This was exactly what I needed...I am moving towards a rustic outdoor garden patio structure with timber framing...and thought that some straw bale short walls would be nice...maybe 3-4 feet in height...open on the side facing in towards the garden...So, thank you for this and your informed by trial and error experience...very helpful...
Thanks! I just finished framing a straw bale house in Nova Scotia and you gave me an idea about how to finish the entrance to the home. Most of the house will be covered with shiplap for the very conditions you describe - wet, rainy and extreme temperatures. And, that last tip about brushing is very helpful.
Thanks Andrew, The reason I did these vids is that when we built ours, there weren't any other vids out there for our climate. We spent a couple of years and lots of testing till we figured out what worked here in Canada LOL. Someone building a cob house in Mexico doesn't really have the same issues we do several degrees latitude North. Wishing you all the best with the finishing on your new build.
Thanks Lynsey, We have some wonderful friends who live in Victoria near Cobden. You have a beautiful Country and we were blessed to visit the Victoria a few years back. We'd love to come back to check out some of the other provinces. Cheers!
Much thanks. I’m going to put as cheap of a wood frame around as I can get and then cover the outside with cheap construction materials. I might get a little fancier on the inside but it’s too much work to cover and there’s no way of knowing if it will hold up.
Thanks so much for sharing this information. I've been looking for a render mix that is a little more durable than just the clay. There's many videos about the straw, clay, sand & lime but I'm not that much of a puritan. I'm going to try rendering an old timber shed I built, by attaching hessian for the render to stick to. The roof overhang isn't very wide so I needed a more robust weather proof mix. Cheers.
Nailed it! We tried to build a load-bearing straw building and every time we tried tightening the top plate, the building would settle more and we just couldn't level it evenly. We finally gave up when the walls began bowing from the torque. Luckily, we were able to attach posts and beams on the inside to build a structure stable enough to support the roof.
Wonder if you could answer a question. I'm thinking about buying an already-built straw bale house that is wonderful. I saw old pix of it when it was being lived in by the builder. He never painted it, inside or out. I've watched a ton of videos, some of which warn against painting because it "seals" the walls in a way they shouldn't be. Because before the most recent owners put it on the market, they painted the entire interior. This has me worried. I don't know what the builder used to coat the straw but I figure, if the builder himself didn't paint the inside that's something to note & maybe it shouldn't have been done. So my question is, was painting the house a problem? I love the house but don't want to take it on if they've defeated the purpose or made it difficult for the straw to stay dry by painting. The exterior is still natural. I've written to quite a few contractors who specialize but can't get anyone to answer. Thanks!
Sure, I can give my 2 cents. In our case, we painted both inside and out. 10 years living in our house now, I can honestly tell you for our climate, even being painted, the house still breathes. The rule I live by is your straw has to live in less than 30% humidity more time of the year to reduce the risk of breaking down naturally. Having walls painted on the interior works as a vapour barrier to reduce interior moisture from migrating into the wall during the cold months. Painting the outside helps ward off driving rains and melting snow from finding its way into the straw. I'm not a professional builder, but our 2 homes we built are located in SK, Canada and are now 10+ years old and doing fine...so I'll let you make your own decisions. Always account for the climate the house is located in.
@@Naturally-Kelly Wow, thanks. That's really helpful. The house is at moderate altitude, somewhere around 6500 feet, so probably fairly dry. I lived at 7500 feet for 16 years & it was *very* dry, single digits for a lot of the summer. I just read a blog that talked about choosing a paint that is more permeable than whatever was used to cover the straw, & that I don't know. I'm trying to find the builder, or I may see if I can get someone local to inspect it & see if they can tell me anything about the construction. Again, thanks very much. This is the link I found, good info I think. www.strawbale.com/devine-paint-on-plastered-walls/
Hi We are wondering. Is this the same recipe for all the coats on a strawbale home? Or just the scratch coat? Also what is the time frame between each coat that you would recommend? You certainly have made our day finding an easy recipe for strawbale. Cheers
Hey Balin, thanks for the question. We like using the same recipe for all coats: cement/lime/sand...but at different ratios. Scratch coat is 3:2:1 - 3 parts sand / 2 parts cement / 1 part lime. All filler coats after this are 3 parts sand / 1.5 parts cement / 1.5 parts lime. Final finishing coat is 3:1:2 - 3 parts sand / 1 part cement / 2 parts lime. Increasing lime gives you a more "buttery" texture - easy to spread and a nice finish but less strength. More cement gives you better bonding to the straw, more structural strength, but harder to finish and spread. Lots of people talk about "breathability" - Been living in our studio space since 2011 and haven't had any issues - even being painted. We experimented with about a dozen recipes for 2 years before deciding to use this one. It's the best by far we know of for places with strong driving wind and rain that would normally degrade a lot of natural finishes.
Excellent, thank you very much for this and all your videos on light clay straw and straw bale. Your down to earth explanations and demos are very helpful indeed. Has your external render mix of 3 sand 2 cement 1 lime worked out okay over the years since you put it on? Does it breathe ok? Thanks again and all good wishes from England.
Thank you 2Langdon. Yes. Our first straw building was completed in 2011. After the 1st year, we had some settling in the bale walls which resulted in a couple of small cracks on 2 outer walls. It was time to repaint about 3 years ago so we filled those cracks at the time of the paint job and had no issues since. On our new build, we have our scratch and brown coats on so I'll see in the spring if anything has shifted or moved. As far as durability - it's been a good fit for our build. Breathability has never been an issue here - but then again, we have a very dry climate in the Fall/Winter, so I would never expect it to be.
@@Naturally-Kelly Thanks so much for your reply. We're at the earliest stages of planning a home and will be building in a part of the UK that does get wet at times, so a strong durable external finish is good to know about. Thank you for making it look so do-able.
Hi thanks for the informative video. Lots of help. Can you tell me, is the mixer you are using one that you have built yourself? Do you know if there are plans for it? Good luck with the build. Regards Ian
Hi Ian, thanks for the comment. Yes. both the cement mixer and straw tumbler are home built by us. I don't have plans on the tumbler but if you go to our UA-cam channel ua-cam.com/users/riverstonestudios check out the videos under "Homebuilt equipment playlist". Might give you a better idea how I built it.
Great video I’m starting my home in the Sonora desert wood is hard to come by mainly al homes are concrete poured standing supports how will this work instead of wood beams? Thanks once again for the help great video
+Eduardo Perez no problem using cement instead of wood. Just be sure to add a channel or rebar or something on your cement posts to anchor and hold your SLC from falling out between.
Thanks NC, Thanks for the reminder. We've spent so much time and energy testing and engineering that its hard when you get comments from people who have opinions - with no real time experience or testing. I have to remind myself that's the reason I post these vids is to help educate others. Thank you for the reminder not to let a bad day get in the way of good people. :)
@@Naturally-Kelly -- Having an engineering background I can relate .. So I have learned it's best to keep my untested hypotheses to myself, unless you would want to hear them? Like trimming the loose straw that sticks out from the bales and/or using thin coating of clay prior to the scratch coat? Sorry those just slipped out :) BTW, since you were so kind to reply.... I had a question.....What's your thoughts about using strawbale construction in the Philadelphia, PA area region? There is a couple of high relative humidity months in the summer... And is there source to find map that shows the viability of using straw bale construction in different parts of the country? Thank you again for taking the time to spread your knowledge and experience....And keep up the good work...(BTW-My apologies since my dyslexia can make it difficult to understand, what I have written)
@@nc3826 Never noticed any dyslexia. Post and beam straw bale has the nick-name of "Nebraska Style" because as settlers moved out west, there were less native trees available which made any construction with lumber expensive on the prairies, so settlers began getting resourceful and used the building materials that were most plentiful. Sod and straw became the building materials of choice. Straw survived the last century but very few of the sod houses now remain as most eroded from weather over the years. In Canada, the area from Manitoba to Alberta is the most prime for straw buildings. In the US, this line would be from about Iowa straight west to Nevada. The coastal regions are places to avoid including the Great Lakes region. Ideally, 30% Relative Humidity is the magic number. Straw will never break down at 30% humidity or less. It will stay golden colour for life. Here in Saskatchewan, we have wet hot summers - some days reaching over 80% humidity from May until August. This is balanced with very dry fall and winter months with humidity getting as low as 10%. These 2 extremes work well. Our cement/lime plaster works to shed some pretty harsh driving rains in the spring and summer that can sometimes erode lime and sand finishes. Lime also has an undesirable trait of holding moisture - It will draw moisture from the bale but then holds it in the finish. Cement works as a wick in both directions so any moisture that does get drawn into the straw from the hot wet spring/summers draws back out during the 6-8 months of dry cold weather. We just replaced a window in our 10 year old straw bale house and found zero moisture damage from rain or humidity - Golden straw from the inside of the wall to the outside finish. In PA, I'm not familiar with your winters or summers so please use your own discretion. The general rule of thumb is as long as you have more months of the year under 30% relative humidity, you're good to go. I know of straw construction in Ontario and Quebec - Some are perfect - some are rotting. Those built in the northern part of the provinces do well, but the ones with moisture issues are all found around the Great Lakes region which tells me their humidity levels range too high for too much of the year. I hope this info helps you make a decision for your region. I don't know of a map showing yearly relative humidity for different areas, but if you live there, you'd have a much better gut instinct than any map. Straw is pretty forgiving - but you just need to make sure you have more days out of the year you need hand lotion than an umbrella :) Wishing you all the best! Cheers! - K
@@Naturally-Kelly Apparently, your mind readers too. Since the "Nebraska Style" of self supporting StrawBale construction was my main focus, except on the south wall were I plan to have more window. The relative humidity seems a little higher than where you are, so a focus on some mediation methods to prevent moisture penetration seems prudent. Like a longer overhanging roof and wood spacer to keep the bails from moisture. Are couple methods what should help. I'm also thinking of looking for breathable mesh/lath to cover it in to? It should add some strength to the stucco and structure and a act as a water repellent from getting straw soaked in heavy rain. Or wait a little for hemp shiv to become more available and use hempcrete instead (similar to hempcrete blocks ie justbiofiber.ca) . Since its more resistant to moisture.... So thanks for validating the general assumptions I already had about StrawBale construction in my area. I just have to decide now which material(s) to use. TC
@@nc3826 Sounds like you're on your way. I've always been interested in Hempcrete. Hemp wasn't available when we built, but there is one farmer in our area planting it now. I'll have to do a bit more digging on it as it looks like a very robust method with a lot of interest as well.
we are considering buying a certain strawbale house. My partner is environmentally sensitive. She got swollen glands. Maybe I felt it too. She thinks the elastomeric (?) stucco on the outside, has trapped some moisture, perhaps wicked up from the ground. I love the house. How do we remediate it? Is it expensive to do?
I can not help you with that. Strawbale is a wonderful building product BUT moisture ALWAYS has to be kept under 30%. If it has wicked or trapped moisture, within a short length of time, natural decomposition (natural rot) will begin. If this is the case, removal of the damaged material is the only remedy. Elastomeric stucco should never be used on natural building products. Even on traditional wood sheathed housing built in the 1980s, it was quickly learned that breathable Tyvek had to be used to allow air behind the elastomeric stucco. It is a beautiful product that doesn't crack easily, but that rubberized stretchability is a downfall on ANY building if not installed with proper building systems in place.
@@nicholasbrassard3512 Insurance is an issue. No building permits needed where we built. We are on an acreage in farming country. Permits here are primarily for urban areas.
Lime works with sand because it key locks between the sand particles like completing a puzzle so it creates a strong combination. Clay naturally has this ability on its own. The various small particles that makeup the clay shrink and tighten. They also have a good bonding ability to the straw. Lime in and of itself does not bond, it "keys" like with sand particles so it won't adhere well to the straw. It also has little strength on its own. After lime has been soaked in water and dried, it becomes very chalk like. You can certainly experiment to find out, but I have my doubts as to wether it would result in a good building product when mixed with a large percentage of straw.
Great video and information! Quick question, would larger pieces of sand from decomposed granite be an issue? I'm thinking of sand that would go through an eighth of an inch screen/classifier to remove the larger pieces or would you suggest a smaller classifier? Thanks again!
roscly83 No issue at all. Here in Saskatchewan we don't have "beach sand". Any sand that is found and used here is typically screened from gravel deposits which are comprised of mostly granite with a small amount of quartz.
Perfect, I was hoping that would be the case. Does the sand you use have fines in it or is it more of a washed material? Also do you have a maximum size sand particle for use in your final coats versus say the sand used in the initial base coat? I'm a hardscape/stone and water feature installer by trade but I have never worked with stucco and hate to just assume lol. And thanks so much for the quick reply sir!
roscly83 No Problem :) We don't concern ourselves with particle size. When you are using a natural plaster with lime and sand only, then the particle size matters as the lime "locks" and keys in the particles of sand, but with using cement in the mix, it takes a lot of the finicky worries out. Couple of things about the particle size though, too large (>1/8" / 3mm) and you'll have a harder time making a nice spread. You don't have to use washed sand, but a lot of dirt or other organic contaminants in your sand will make a weak finish. Also, I'm not sure if you are familiar with "Crusher Dust"...This product won't work at all. It's basically the dust that comes from crushing larger rock. - Great for packing down paths, but not for stucco.
two questions... so this house has a traditional poured concrete foundation? what are alternatives to that you might be able to do yourself? Second, thats a beautiful roof I was wondering if you could talk about about how the roof was done
Thank you Gianna. I've heard of people using rubble foundations with good success. Personally because of the wind where we live, we chose concrete so we could fasten the walls and roof to the foundation and not have it move. I suppose you could also do a wood foundation...but depending on how thick your walls (more so how thick you make your plaster/stucco finishes) your weight load may add up quickly so your wood footings would have to be able to take the weight of the walls AND the roof without movement. Regarding the roof. We'll put a video out down the road on how we built it. Cheers!
Mark Van den Borre Hey Mark, thanks for the comment and the concern. We've done A LOT of testing plus the house we finished and have been living in for 4 years now is finished this way. The recipe I shared is very breathable. Trust me living on the open prairies with 100 km / hr winds. No issues with breath-ability. It was also a concern of ours and why we have done so much testing with it. We also have areas of our finished walls that we've monitored for the 4 year duration with no issues holding moisture. All the books we've read talk about not using cement. I have to assume it comes from more of a purist belief and not as much a tested theory - at least for Western Canadian climates. Proof can also be seen by comparing cement based stuccos used in traditional American construction on homes built in the 1970's. There were no issues with mould until acrylic stucco came onto the market in the 1980's. Acrylic stucco brought with it tons of issues with mould and as a result construction methods were altered to adjust for the new product.
Do you mean generally speaking building with straw or because you wet your walls to adhere the stucco? In any case, your walls can be wet, mold is never an issue unless you have sustained moisture of over 30% for weeks or months at a time. A typical wood/drywall bathroom is no different - take a shower and your walls will be wet and can start to mold. They don't though because the period of time they are that wet is short enough that it dries below 30% humidity. If you have bad ventilation or if your bathroom walls are constantly wet - you have mold. Building with straw is no different. Incidentally - hay is typically called Green Feed for animals and is typically not used in construction. Straw is what is used. It typically is a dry fibre waste product from cereal crops and not feed for animals although it is used as bedding for animals. "Hay" typically is baled with a higher moisture content to keep nutrient value for feeding animals thus where it can also mold when baled.
Thanks Jeff, and good question. We are real time testing. Right now we have been living 10 years in our straw bale house. In some inside areas of our house we have exposed beams and we've noted shrinkage in the wood leaving a gap in the stucco...which means they've actually been losing moisture over the years. We changed out a failed window 2 years ago and did a physical inspection of the straw in the cavity. It was pleasant to find golden straw all the way around. We figued if there was going to be any ice dams or deteriation, it would have been around a failed window unit so I don't think we'll see any issues at least for a few years to come.
The straw is much more apt to deteriate faster than the wood so as long as the moisture content stays less than 30% more time of the year than not...break down of the materials should never be a concern.
Thanks for the question Cody - This is one of the reasons we like SLC over Straw bale construction. Because bale construction uses individual "bricks of straw - you must cover and sew the bales together with some sort of mesh (plastic mesh/chicken wire/stucco wire etc) to keep cracking to a minimum with settling and shrinkage occurring between each bale. Because the entire wall of SLC is formed as one piece and the fibres are already bound to each other through the mixing and packing process - there is no need for additional mesh except in areas where you have unlike materials such as your wood beams touching the straw. Both products will expand/contract at different rates both due to heat/cold as well as moisture through humidity which will result in your finishing cracking and separating between the two mixed materials unless a mesh is used to help and tie the two materials together so on this building - mesh is only used between wood beams and straw where both are going to be plaster/stucco finished and we want the beam hidden in the wall instead of exposed.
Yes. Stucco fire proofs, seals, and gives a tough, durable water proof finish to the straw. In addition to allowing rain to shed off, it also allows wicks excess moisture from inside the walls to help keep condensation to a minimum in cold climates where that becomes a concern.
+Antonio Vázquez Hey Antonio, need a bit more information - when you say perimeter wall, what is your wall built from? Every material is different and your global location will also dictate based on your climate. For example, here in Canada, SLC - I stucco directly onto the straw - It grips well and the straw and stucco work together for re-enforcement. Straw Bale - I sew stucco mesh on first, then stucco. Plywood/OSB outer sheeting - I use a breathable barrier like GAF FeltBuster or Typar house wrap then tack stucco mesh on top. These methods are based on our climate conditions and materials used.
+Riverstone Studios - Natural Organic Skin and Body Care Hello i live in Rosarito baja ca mexico close to the beach.i plan building eith hay bales and its just a wall around my property instead of a fence..thankyou so much for responding
Antonio Vázquez Ah yes! Nice! We have friends who spent 4 months along that coast line last year. Best suggestion I can give is if you are using bales, cover them with stucco mesh or plastic mesh. The mesh can be attached either with homemade staples made from wire or you can sew the two sides together using twine and a long homemade wooden needle. I would not use a vapour barrier product. A vapour barrier will decrease your structural strength and may increase the risk of moisture not being able to move through the bale. I would just stucco onto the surface. Over time the bales tend to settle and without some sort of mesh product for reinforcement, you will probably have cracks along your bale lines. Show less
Antonio Vázquez If you are concerned about rain getting in the top, I would ensure the finishing of the stucco on the top was curved and sloped enough that there was no chance of water pooling anywhere. You can also paint the stucco. We used latex outdoor on our straw bale house with very good success and no issues 5 years in with either moisture or condensation. With the winds we get there is still good breathability. I am assuming along the Pacific Coast, you get pretty good air movement as well.
Unlike acrylic stucco that seals tight, natural lime and cement plasters actually work to wick moisture - in both directions. We live in a climate that sometimes has 10% relative humidity during the winter months so moisture draws out of the walls easily. Moisture has never been an issue in our first house nor in this one. I wouldn't recommend ANY natural fiber construction in tropical or humid areas - cob and adobe perform much better in those regions, but northern, midwest and arrid regions, moisture in the walls is never a concern. The cement plasters breathe very well yet work to shed off water from rain and snow...best of both worlds :) Thank you for the question.
Hi there! I started constructing a straw light clay house based upon inspiration from your videos about 6 months ago. Well, the walls have dried and it's time for the plaster but now I have some questions I can seem to get clear on in regards to where traditional building practices meet alternative ones. Specifically, I'm thinking about my Windows, housewrap, and flashing. I was wondering if these practices need to be incorporated or if there is more forgiveness for moisture penetration due to the fact that the walls are breathable and the clay traps/releases moisture. There are videos about stucco out there where builders seem to be deeply concerned about moisture penetration. Do you think I should flash my Windows or apply housewrap?
+Curtis Humphrey Sorry its taken so long to get back. I missed seeing your comment. Re: moisture penetration - every year the housing industry comes up with new products and new ways of doing things. I'm not a purist and I believe in mixing old with new along with common sense. Use whatever products you need to get a good seal around your doors and windows to keep water out of your SLC. This is one of the reasons we chose to use cement based stucco and paint for a finish on SLC. It still breathes but sheds water well. As far as around our windows, we frame with oversized cedar planks (5" wide) so water has a harder time reaching the edge of the window and we use a good quality flexible latex caulk. I never worry too much about the sides, but any top edges where water can sit, I always check for cracks or separations in the caulking before the spring rains start coming. SLC will last longer than you or I, but only if it stays dry. Any large amounts of water that gets channelled into the straw will eventually cause it to fail just like any other building product. Regarding using house wrap around the whole house, I've never tried it so I can't comment. You'd have to do some of your own experimenting with that one. We stucco directly onto the straw with very good success and longevity.
+Curtis Humphrey You definitely need to flash around all doors and windows. SLC is a great product, but just like every other building style, you have to keep water from travelling inward into your wall construction. Always look for ways to shed the water away from your walls, regardless of what type of finish you put on them. Caulk, flashing, trim. All good options and all can be used together. Breathing isn't an issue for humidity...rain channelling in is. humidity will breath out, but water penetrated from rain won't. Hope that helps.
Riverstone Studios - Eco-Body Care it helps tremendously and means I have to get my ass in gear to do a second coat of stucco, and paint, caulk, and trim my Windows before winter rain sets in.....!
This was exactly what I needed...I am moving towards a rustic outdoor garden patio structure with timber framing...and thought that some straw bale short walls would be nice...maybe 3-4 feet in height...open on the side facing in towards the garden...So, thank you for this and your informed by trial and error experience...very helpful...
Several excellent points here that apply even beyond the present project. Thanks for a nice video.
Awesome tutorial. Thanks!
Thanks! I just finished framing a straw bale house in Nova Scotia and you gave me an idea about how to finish the entrance to the home. Most of the house will be covered with shiplap for the very conditions you describe - wet, rainy and extreme temperatures. And, that last tip about brushing is very helpful.
Thanks Andrew, The reason I did these vids is that when we built ours, there weren't any other vids out there for our climate. We spent a couple of years and lots of testing till we figured out what worked here in Canada LOL. Someone building a cob house in Mexico doesn't really have the same issues we do several degrees latitude North. Wishing you all the best with the finishing on your new build.
Thanks so much for this valuable information. I am in the brink of building and this is really helpful since I live in a harsher climate too!
Wishing you all the best on your build Fida - Never be afraid to experiment before committing to the full job.
Thank you very well done
thanks man,from canary islands.............
Hello from Australia, I have watched most of your guides and I think your really informative. Keep up the good work!
Thanks Lynsey, We have some wonderful friends who live in Victoria near Cobden. You have a beautiful Country and we were blessed to visit the Victoria a few years back. We'd love to come back to check out some of the other provinces. Cheers!
Much thanks. I’m going to put as cheap of a wood frame around as I can get and then cover the outside with cheap construction materials. I might get a little fancier on the inside but it’s too much work to cover and there’s no way of knowing if it will hold up.
So many great tips 👍
Really packed.
Thanks
Thanks for sharing your experience with us. Good tips and thorough explanations.
That was a good hands on video. Very helpful.
Thanks!
Thank you for the tips!
Glad you found it useful 🥰
I love this video.
New subscriber just because you're smart and that makes me smart. 😄
Really nice job mate! I am building straw bale down in Tubac Az.I am going to use your mixtures.
Wishing you all the best with your build
Thanks so much for sharing this information. I've been looking for a render mix that is a little more durable than just the clay. There's many videos about the straw, clay, sand & lime but I'm not that much of a puritan. I'm going to try rendering an old timber shed I built, by attaching hessian for the render to stick to. The roof overhang isn't very wide so I needed a more robust weather proof mix. Cheers.
Good luck Juliet on your project :)
Nice informative video well done
That was very good!
I like it.
thanks very much for your video and good explanations.
Post and beam with straw bale as insulation would be ok. The straw will settle and will Crack the finish if the roof is set on straw bales.
Nailed it! We tried to build a load-bearing straw building and every time we tried tightening the top plate, the building would settle more and we just couldn't level it evenly. We finally gave up when the walls began bowing from the torque. Luckily, we were able to attach posts and beams on the inside to build a structure stable enough to support the roof.
Thank you. Invaluable information. What do you put in your “brown coat” and “ finish coat”?
My apologies. Just found my answer in one of your replies
Great video 👍🏻 I have a question? Can you use chicken wire on the outside of the bales and then stucco over the wire?
Absolutely ♥️ Chicken wire works well.
I just recently saw video saying cement is not a good option for strawbale homes , because it is not breathable......
nice video, thanks for the advice
Wonder if you could answer a question. I'm thinking about buying an already-built straw bale house that is wonderful. I saw old pix of it when it was being lived in by the builder. He never painted it, inside or out. I've watched a ton of videos, some of which warn against painting because it "seals" the walls in a way they shouldn't be. Because before the most recent owners put it on the market, they painted the entire interior. This has me worried. I don't know what the builder used to coat the straw but I figure, if the builder himself didn't paint the inside that's something to note & maybe it shouldn't have been done.
So my question is, was painting the house a problem? I love the house but don't want to take it on if they've defeated the purpose or made it difficult for the straw to stay dry by painting. The exterior is still natural.
I've written to quite a few contractors who specialize but can't get anyone to answer. Thanks!
Sure, I can give my 2 cents. In our case, we painted both inside and out. 10 years living in our house now, I can honestly tell you for our climate, even being painted, the house still breathes. The rule I live by is your straw has to live in less than 30% humidity more time of the year to reduce the risk of breaking down naturally. Having walls painted on the interior works as a vapour barrier to reduce interior moisture from migrating into the wall during the cold months. Painting the outside helps ward off driving rains and melting snow from finding its way into the straw. I'm not a professional builder, but our 2 homes we built are located in SK, Canada and are now 10+ years old and doing fine...so I'll let you make your own decisions. Always account for the climate the house is located in.
@@Naturally-Kelly Wow, thanks. That's really helpful. The house is at moderate altitude, somewhere around 6500 feet, so probably fairly dry. I lived at 7500 feet for 16 years & it was *very* dry, single digits for a lot of the summer. I just read a blog that talked about choosing a paint that is more permeable than whatever was used to cover the straw, & that I don't know. I'm trying to find the builder, or I may see if I can get someone local to inspect it & see if they can tell me anything about the construction.
Again, thanks very much. This is the link I found, good info I think. www.strawbale.com/devine-paint-on-plastered-walls/
Thank you!!!!!!
👍
Hi
We are wondering. Is this the same recipe for all the coats on a strawbale home? Or just the scratch coat? Also what is the time frame between each coat that you would recommend? You certainly have made our day finding an easy recipe for strawbale. Cheers
Hey Balin, thanks for the question. We like using the same recipe for all coats: cement/lime/sand...but at different ratios. Scratch coat is 3:2:1 - 3 parts sand / 2 parts cement / 1 part lime. All filler coats after this are 3 parts sand / 1.5 parts cement / 1.5 parts lime. Final finishing coat is 3:1:2 - 3 parts sand / 1 part cement / 2 parts lime. Increasing lime gives you a more "buttery" texture - easy to spread and a nice finish but less strength. More cement gives you better bonding to the straw, more structural strength, but harder to finish and spread.
Lots of people talk about "breathability" - Been living in our studio space since 2011 and haven't had any issues - even being painted. We experimented with about a dozen recipes for 2 years before deciding to use this one. It's the best by far we know of for places with strong driving wind and rain that would normally degrade a lot of natural finishes.
Excellent, thank you very much for this and all your videos on light clay straw and straw bale. Your down to earth explanations and demos are very helpful indeed. Has your external render mix of 3 sand 2 cement 1 lime worked out okay over the years since you put it on? Does it breathe ok? Thanks again and all good wishes from England.
Thank you 2Langdon. Yes. Our first straw building was completed in 2011. After the 1st year, we had some settling in the bale walls which resulted in a couple of small cracks on 2 outer walls. It was time to repaint about 3 years ago so we filled those cracks at the time of the paint job and had no issues since. On our new build, we have our scratch and brown coats on so I'll see in the spring if anything has shifted or moved. As far as durability - it's been a good fit for our build. Breathability has never been an issue here - but then again, we have a very dry climate in the Fall/Winter, so I would never expect it to be.
@@Naturally-Kelly Thanks so much for your reply. We're at the earliest stages of planning a home and will be building in a part of the UK that does get wet at times, so a strong durable external finish is good to know about. Thank you for making it look so do-able.
Hi thanks for the informative video. Lots of help. Can you tell me, is the mixer you are using one that you have built yourself? Do you know if there are plans for it? Good luck with the build. Regards Ian
Hi Ian, thanks for the comment. Yes. both the cement mixer and straw tumbler are home built by us. I don't have plans on the tumbler but if you go to our UA-cam channel ua-cam.com/users/riverstonestudios check out the videos under "Homebuilt equipment playlist". Might give you a better idea how I built it.
Excellent video, thank you!
Great video I’m starting my home in the Sonora desert wood is hard to come by mainly al homes are concrete poured standing supports how will this work instead of wood beams? Thanks once again for the help great video
+Eduardo Perez no problem using cement instead of wood. Just be sure to add a channel or rebar or something on your cement posts to anchor and hold your SLC from falling out between.
Thx for all the great info...And pls dont get offended when ppl have differing view on seem best to the them...
Thanks NC, Thanks for the reminder. We've spent so much time and energy testing and engineering that its hard when you get comments from people who have opinions - with no real time experience or testing. I have to remind myself that's the reason I post these vids is to help educate others. Thank you for the reminder not to let a bad day get in the way of good people. :)
@@Naturally-Kelly -- Having an engineering background I can relate .. So I have learned it's best to keep my untested hypotheses to myself, unless you would want to hear them? Like trimming the loose straw that sticks out from the bales and/or using thin coating of clay prior to the scratch coat? Sorry those just slipped out :)
BTW, since you were so kind to reply.... I had a question.....What's your thoughts about using strawbale construction in the Philadelphia, PA area region? There is a couple of high relative humidity months in the summer... And is there source to find map that shows the viability of using straw bale construction in different parts of the country?
Thank you again for taking the time to spread your knowledge and experience....And keep up the good work...(BTW-My apologies since my dyslexia can make it difficult to understand, what I have written)
@@nc3826 Never noticed any dyslexia. Post and beam straw bale has the nick-name of "Nebraska Style" because as settlers moved out west, there were less native trees available which made any construction with lumber expensive on the prairies, so settlers began getting resourceful and used the building materials that were most plentiful. Sod and straw became the building materials of choice. Straw survived the last century but very few of the sod houses now remain as most eroded from weather over the years.
In Canada, the area from Manitoba to Alberta is the most prime for straw buildings. In the US, this line would be from about Iowa straight west to Nevada. The coastal regions are places to avoid including the Great Lakes region. Ideally, 30% Relative Humidity is the magic number. Straw will never break down at 30% humidity or less. It will stay golden colour for life. Here in Saskatchewan, we have wet hot summers - some days reaching over 80% humidity from May until August. This is balanced with very dry fall and winter months with humidity getting as low as 10%. These 2 extremes work well. Our cement/lime plaster works to shed some pretty harsh driving rains in the spring and summer that can sometimes erode lime and sand finishes. Lime also has an undesirable trait of holding moisture - It will draw moisture from the bale but then holds it in the finish. Cement works as a wick in both directions so any moisture that does get drawn into the straw from the hot wet spring/summers draws back out during the 6-8 months of dry cold weather. We just replaced a window in our 10 year old straw bale house and found zero moisture damage from rain or humidity - Golden straw from the inside of the wall to the outside finish.
In PA, I'm not familiar with your winters or summers so please use your own discretion. The general rule of thumb is as long as you have more months of the year under 30% relative humidity, you're good to go. I know of straw construction in Ontario and Quebec - Some are perfect - some are rotting. Those built in the northern part of the provinces do well, but the ones with moisture issues are all found around the Great Lakes region which tells me their humidity levels range too high for too much of the year.
I hope this info helps you make a decision for your region. I don't know of a map showing yearly relative humidity for different areas, but if you live there, you'd have a much better gut instinct than any map. Straw is pretty forgiving - but you just need to make sure you have more days out of the year you need hand lotion than an umbrella :) Wishing you all the best! Cheers! - K
@@Naturally-Kelly Apparently, your mind readers too. Since the "Nebraska Style" of self supporting StrawBale construction was my main focus, except on the south wall were I plan to have more window.
The relative humidity seems a little higher than where you are, so a focus on some mediation methods to prevent moisture penetration seems prudent. Like a longer overhanging roof and wood spacer to keep the bails from moisture. Are couple methods what should help. I'm also thinking of looking for breathable mesh/lath to cover it in to? It should add some strength to the stucco and structure and a act as a water repellent from getting straw soaked in heavy rain.
Or wait a little for hemp shiv to become more available and use hempcrete instead (similar to hempcrete blocks ie justbiofiber.ca) . Since its more resistant to moisture....
So thanks for validating the general assumptions I already had about StrawBale construction in my area. I just have to decide now which material(s) to use. TC
@@nc3826 Sounds like you're on your way. I've always been interested in Hempcrete. Hemp wasn't available when we built, but there is one farmer in our area planting it now. I'll have to do a bit more digging on it as it looks like a very robust method with a lot of interest as well.
we are considering buying a certain strawbale house. My partner is environmentally sensitive. She got swollen glands. Maybe I felt it too. She thinks the elastomeric (?) stucco on the outside, has trapped some moisture, perhaps wicked up from the ground. I love the house. How do we remediate it? Is it expensive to do?
I can not help you with that. Strawbale is a wonderful building product BUT moisture ALWAYS has to be kept under 30%. If it has wicked or trapped moisture, within a short length of time, natural decomposition (natural rot) will begin. If this is the case, removal of the damaged material is the only remedy.
Elastomeric stucco should never be used on natural building products. Even on traditional wood sheathed housing built in the 1980s, it was quickly learned that breathable Tyvek had to be used to allow air behind the elastomeric stucco. It is a beautiful product that doesn't crack easily, but that rubberized stretchability is a downfall on ANY building if not installed with proper building systems in place.
It's like a giant cake.
Totally :)
Thanks for the very informative video! How long did it take you to coat the entire house?
About a week start to finish inside and out.
@@Naturally-Kelly damn, thats good! You run into any problems getting building permits or some such?
@@nicholasbrassard3512 Insurance is an issue. No building permits needed where we built. We are on an acreage in farming country. Permits here are primarily for urban areas.
Can you mix lime with the straw instead of clay?
Lime works with sand because it key locks between the sand particles like completing a puzzle so it creates a strong combination. Clay naturally has this ability on its own. The various small particles that makeup the clay shrink and tighten. They also have a good bonding ability to the straw.
Lime in and of itself does not bond, it "keys" like with sand particles so it won't adhere well to the straw. It also has little strength on its own. After lime has been soaked in water and dried, it becomes very chalk like.
You can certainly experiment to find out, but I have my doubts as to wether it would result in a good building product when mixed with a large percentage of straw.
Great video and information! Quick question, would larger pieces of sand from decomposed granite be an issue? I'm thinking of sand that would go through an eighth of an inch screen/classifier to remove the larger pieces or would you suggest a smaller classifier? Thanks again!
roscly83 No issue at all. Here in Saskatchewan we don't have "beach sand". Any sand that is found and used here is typically screened from gravel deposits which are comprised of mostly granite with a small amount of quartz.
Perfect, I was hoping that would be the case. Does the sand you use have fines in it or is it more of a washed material? Also do you have a maximum size sand particle for use in your final coats versus say the sand used in the initial base coat? I'm a hardscape/stone and water feature installer by trade but I have never worked with stucco and hate to just assume lol.
And thanks so much for the quick reply sir!
roscly83 No Problem :) We don't concern ourselves with particle size. When you are using a natural plaster with lime and sand only, then the particle size matters as the lime "locks" and keys in the particles of sand, but with using cement in the mix, it takes a lot of the finicky worries out. Couple of things about the particle size though, too large (>1/8" / 3mm) and you'll have a harder time making a nice spread. You don't have to use washed sand, but a lot of dirt or other organic contaminants in your sand will make a weak finish. Also, I'm not sure if you are familiar with "Crusher Dust"...This product won't work at all. It's basically the dust that comes from crushing larger rock. - Great for packing down paths, but not for stucco.
two questions... so this house has a traditional poured concrete foundation? what are alternatives to that you might be able to do yourself? Second, thats a beautiful roof I was wondering if you could talk about about how the roof was done
Thank you Gianna. I've heard of people using rubble foundations with good success. Personally because of the wind where we live, we chose concrete so we could fasten the walls and roof to the foundation and not have it move. I suppose you could also do a wood foundation...but depending on how thick your walls (more so how thick you make your plaster/stucco finishes) your weight load may add up quickly so your wood footings would have to be able to take the weight of the walls AND the roof without movement. Regarding the roof. We'll put a video out down the road on how we built it. Cheers!
The cement will kill the breathability of your building. You will get humidity in your bales in the medium term!
Mark Van den Borre Hey Mark, thanks for the comment and the concern. We've done A LOT of testing plus the house we finished and have been living in for 4 years now is finished this way. The recipe I shared is very breathable. Trust me living on the open prairies with 100 km / hr winds. No issues with breath-ability. It was also a concern of ours and why we have done so much testing with it. We also have areas of our finished walls that we've monitored for the 4 year duration with no issues holding moisture. All the books we've read talk about not using cement. I have to assume it comes from more of a purist belief and not as much a tested theory - at least for Western Canadian climates. Proof can also be seen by comparing cement based stuccos used in traditional American construction on homes built in the 1970's. There were no issues with mould until acrylic stucco came onto the market in the 1980's. Acrylic stucco brought with it tons of issues with mould and as a result construction methods were altered to adjust for the new product.
What about mold and meldew in hay?
Do you mean generally speaking building with straw or because you wet your walls to adhere the stucco? In any case, your walls can be wet, mold is never an issue unless you have sustained moisture of over 30% for weeks or months at a time. A typical wood/drywall bathroom is no different - take a shower and your walls will be wet and can start to mold. They don't though because the period of time they are that wet is short enough that it dries below 30% humidity. If you have bad ventilation or if your bathroom walls are constantly wet - you have mold. Building with straw is no different. Incidentally - hay is typically called Green Feed for animals and is typically not used in construction. Straw is what is used. It typically is a dry fibre waste product from cereal crops and not feed for animals although it is used as bedding for animals. "Hay" typically is baled with a higher moisture content to keep nutrient value for feeding animals thus where it can also mold when baled.
Wow! Couldn't hear a word you were saying about the trowels due to wind!!!
Ima do dis....lol ty
Enjoyed your video. Just one question your enclosed timber and breathable walls with moisture will your timber rot over time say 10 15 years
Thanks Jeff, and good question. We are real time testing. Right now we have been living 10 years in our straw bale house. In some inside areas of our house we have exposed beams and we've noted shrinkage in the wood leaving a gap in the stucco...which means they've actually been losing moisture over the years. We changed out a failed window 2 years ago and did a physical inspection of the straw in the cavity. It was pleasant to find golden straw all the way around. We figued if there was going to be any ice dams or deteriation, it would have been around a failed window unit so I don't think we'll see any issues at least for a few years to come.
The straw is much more apt to deteriate faster than the wood so as long as the moisture content stays less than 30% more time of the year than not...break down of the materials should never be a concern.
Thank you I live in michigan much of the same climate as Canada
question: did you put your chicken wire on the strawbale, or just were there is an intersection of straw and wood?
Thanks for the question Cody - This is one of the reasons we like SLC over Straw bale construction. Because bale construction uses individual "bricks of straw - you must cover and sew the bales together with some sort of mesh (plastic mesh/chicken wire/stucco wire etc) to keep cracking to a minimum with settling and shrinkage occurring between each bale.
Because the entire wall of SLC is formed as one piece and the fibres are already bound to each other through the mixing and packing process - there is no need for additional mesh except in areas where you have unlike materials such as your wood beams touching the straw. Both products will expand/contract at different rates both due to heat/cold as well as moisture through humidity which will result in your finishing cracking and separating between the two mixed materials unless a mesh is used to help and tie the two materials together so on this building - mesh is only used between wood beams and straw where both are going to be plaster/stucco finished and we want the beam hidden in the wall instead of exposed.
So does the stucco water proof the straw? Iv seen other builds add a water proof paper to it. Im very new obviously
Yes. Stucco fire proofs, seals, and gives a tough, durable water proof finish to the straw. In addition to allowing rain to shed off, it also allows wicks excess moisture from inside the walls to help keep condensation to a minimum in cold climates where that becomes a concern.
Was this ever finished? New updates?
i want to build a perimeter wall do i need to put roofing paper on top or can i just stucco the whole thing??thankyou
+Antonio Vázquez Hey Antonio, need a bit more information - when you say perimeter wall, what is your wall built from? Every material is different and your global location will also dictate based on your climate. For example, here in Canada, SLC - I stucco directly onto the straw - It grips well and the straw and stucco work together for re-enforcement. Straw Bale - I sew stucco mesh on first, then stucco. Plywood/OSB outer sheeting - I use a breathable barrier like GAF FeltBuster or Typar house wrap then tack stucco mesh on top. These methods are based on our climate conditions and materials used.
+Riverstone Studios - Natural Organic Skin and Body Care Hello i live in Rosarito baja ca mexico close to the beach.i plan building eith hay bales and its just a wall around my property instead of a fence..thankyou so much for responding
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Antonio Vázquez
Ah yes! Nice! We have friends who spent 4 months along that coast line last year. Best suggestion I can give is if you are using bales, cover them with stucco mesh or plastic mesh. The mesh can be attached either with homemade staples made from wire or you can sew the two sides together using twine and a long homemade wooden needle. I would not use a vapour barrier product. A vapour barrier will decrease your structural strength and may increase the risk of moisture not being able to move through the bale. I would just stucco onto the surface. Over time the bales tend to settle and without some sort of mesh product for reinforcement, you will probably have cracks along your bale lines.
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Antonio Vázquez If you are concerned about rain getting in the top, I would ensure the finishing of the stucco on the top was curved and sloped enough that there was no chance of water pooling anywhere. You can also paint the stucco. We used latex outdoor on our straw bale house with very good success and no issues 5 years in with either moisture or condensation. With the winds we get there is still good breathability. I am assuming along the Pacific Coast, you get pretty good air movement as well.
with all that water. Arent you afraid of fungus and stuff inside the walls, when you close them off?
Unlike acrylic stucco that seals tight, natural lime and cement plasters actually work to wick moisture - in both directions. We live in a climate that sometimes has 10% relative humidity during the winter months so moisture draws out of the walls easily. Moisture has never been an issue in our first house nor in this one. I wouldn't recommend ANY natural fiber construction in tropical or humid areas - cob and adobe perform much better in those regions, but northern, midwest and arrid regions, moisture in the walls is never a concern. The cement plasters breathe very well yet work to shed off water from rain and snow...best of both worlds :) Thank you for the question.
Hi there! I started constructing a straw light clay house based upon inspiration from your videos about 6 months ago. Well, the walls have dried and it's time for the plaster but now I have some questions I can seem to get clear on in regards to where traditional building practices meet alternative ones. Specifically, I'm thinking about my Windows, housewrap, and flashing. I was wondering if these practices need to be incorporated or if there is more forgiveness for moisture penetration due to the fact that the walls are breathable and the clay traps/releases moisture. There are videos about stucco out there where builders seem to be deeply concerned about moisture penetration. Do you think I should flash my Windows or apply housewrap?
+Curtis Humphrey Sorry its taken so long to get back. I missed seeing your comment. Re: moisture penetration - every year the housing industry comes up with new products and new ways of doing things. I'm not a purist and I believe in mixing old with new along with common sense. Use whatever products you need to get a good seal around your doors and windows to keep water out of your SLC. This is one of the reasons we chose to use cement based stucco and paint for a finish on SLC. It still breathes but sheds water well. As far as around our windows, we frame with oversized cedar planks (5" wide) so water has a harder time reaching the edge of the window and we use a good quality flexible latex caulk. I never worry too much about the sides, but any top edges where water can sit, I always check for cracks or separations in the caulking before the spring rains start coming. SLC will last longer than you or I, but only if it stays dry. Any large amounts of water that gets channelled into the straw will eventually cause it to fail just like any other building product. Regarding using house wrap around the whole house, I've never tried it so I can't comment. You'd have to do some of your own experimenting with that one. We stucco directly onto the straw with very good success and longevity.
+Curtis Humphrey You definitely need to flash around all doors and windows. SLC is a great product, but just like every other building style, you have to keep water from travelling inward into your wall construction. Always look for ways to shed the water away from your walls, regardless of what type of finish you put on them. Caulk, flashing, trim. All good options and all can be used together. Breathing isn't an issue for humidity...rain channelling in is. humidity will breath out, but water penetrated from rain won't. Hope that helps.
Riverstone Studios - Eco-Body Care it helps tremendously and means I have to get my ass in gear to do a second coat of stucco, and paint, caulk, and trim my Windows before winter rain sets in.....!
scratch coat , good he remembered to scratch it ..
LOL - always do but darn near forgot it in the video.