This book is a comprehensive guide for anyone who wants to build a second unit on their property. ua-cam.com/users/postUgkxzaRUJNcbypw-fRBDbqqz43ULIa-1EGP- It showcases various types of houses, such as garage apartments, with photos, videos, and floor plans. The book provides the square footage and the dimensions of each house, as well as the option to order the plans or customize them according to your preferences. You can choose from a range of styles, from ultra modern to cottages and A frame lake houses. The book also offers suggestions for sheds, pool houses, and office studio buildings. This book is an ideal resource for the aspiring home designer.
Thanks m8! ❤Best I could find, the rest were out there! One even recomended AGAINST ag- pipe, and pushed skinny rigid pvc pipe, dirt backfilled🤣 no sight of gravel or fabric...what the heck!? Thanks for your sanity and simple to understand vid xx
Top shelf video, thanks for the upload. I had a retaining wall built 6 months ago and a tradie who recently worked on my property noticed it's already atlease 10 mm offline. Either he didn't put a drainage pipe down or not enough of aggi or gravel mix. In short I am getting the guy in again to 'please explain'
In the process of filling behind my wall and not sure how much gravel. The wall is 1200mm high so from your video I will continue to fill with gravel. Will add geo fabric as a separation between soil and gravel. Thank you for your video, answered my question about how much gravel. Mt Colah, NSW
My retaining wall failed exactly where the previous owner added geo fabric. Over a short period of time, the fabric gets clogged by dirt and water begins to accumulate on top and behind rather than flow through the porous wall which is what the wall was designed to do.
Could somebody please advise? If I put the 'geo tech' fabric in place, won't this just stop all of the drainage? Is 'geo tech' the same as 'damp proofing'? Is 'geo tech' porous? I live in the UK - what is the local name for 'geo tech?' Many Thanks!
@@virabadrasana That’s exactly the same thing I wanted to know and just asked the same question myself lol 🤷♂️ Did you ever find out the answer to this question?
If you have a CLAY type soil DON'T put geofabric vertically. It will get clogged up. Hydrostatic pressure will build up behind the clogged fabric. This will push against the drainage stone. The drainage stone will in turn push againt the wall. The wall will then belly and potentially blow out. For CLAY soils only put the geofabric horizontally over the drainage rock, don't run it vertically down the side between the CLAY soil and the drainage stone.
thank you so much now i know why the rain waters keeps coming through the wall. I didnt put enough gravel and too much old fill. damn should of research more before filling it :(
To my knowledge putting an ag pipe directly on sand necessitates the use of a socked ag pipe or else the sand will just migrate into the Ag over time (and wash away). Not sure why you're not just putting the Ag on 100mm of the same drainage aggregate instead (and using geotech behind wall as discussed in vid)
Hi Mate, the bed of sand just allows you to easily get the slope you will need on the pipe. You could use the same material as the drainage aggregate if you like.
Great video mate. I’ve searched to see if you have been asked this already but I couldn’t see it. Would it be beneficial to lay a plastic sheet behind the wall, between it and the blue metal to prevent water coming through it?
Hi Mate, no, unless you have some reason for not letting water through other than looks. You really want the water to escape so it doesnt build up presure behind your wall.
@@Buildsum that makes total sense. I have to replace a retaining wall under my house, so I think to help reduce the amount of water coming through I may run 2 Agi-pipes with a plastic sheet to help reduce water coming through. I will take the extra weight from water buildup into serious consideration when choosing the material sizes etc. Thanks for the reply and great info.
I’m building an 8 foot long retaining wall coming out from my house. The wall will step down gradually to match the ground that slopes away from the house. My wall will be at its highest point about 2 1/2’ tall at the house and will step down over that 8 feet to about 1 foot tall. My trench is 10” wide and my block is 7” wide. I’ve put down 5” of Class 5 rock and packed it down then have about half to 1” an inch of sand on top of that to level it off nicely. I’ll put gravel and fabric between the wall and dirt like you show here. Since the ground on the outside of the wall slopes so quickly over 8’ so I need the drainage tubing? Thanks
We have a high retaining wall in our back garden (about 8ft) that holds back our neighbours garden which is alot higher than ours. It does have small drainage pipes at the bottom of the wall, however the wall is constantly wet in patches. Could this be because the backfill has mixed and there is now soil directly behind the wall? The wall was built by our house builder so not sure what they have done behind it 😅
Sorry for my question you might not see it but at the moment I am working on a retaining wall system for stone load-bearing walls (two floors in direct contact with the river ,However, I am not sure if I need to use the pipes and what the purpose of it in that case and how thick my wall need to be in order to hold the structure
Hey quick question what can you do if the dirt has been washed out from below the wall and now the wall is on the air and dirt is still washing below it, this is happening to me right now at the moment half of my garden has washed out from below and my wall already fell also it is still raining so my garden is still being washed out i tried making a retention wall but dirt is still washing into it and it is dangerous please can you give me a suggestion or something thanks...
Hi Miguel, there is not much you can do until the rain stops, if the water and soil is running under the wall it sounds like you should dig in a concrete footing that runs along the bottom of the wall. Then you will have to dig out behind the wall like shown in the video and install the Ag pipe and the well draining material. Unfortunately it sounds like you have go a real mess on your hands however you may have to make some more in order to be a wall that will do the job that you need it to. Hope this helps.
Would fiberglass mat work instead of "geo tech" mat? In Vietnam over here, we don't have fancy construction materials. Or could that clog up and defeat the purpose of the draining layer, as mentioned in another comment? Also: no weep holes?
I've got a house where the brickwork has been built into the hillside without any waterproofing or drainage, and the subfloor is flooding behind it. Plumber had a go but only went halfway down so water is penetrating underneath. Would this technique be the same for a structural house wall, maybe just with waterproofing on the house side?
Thanks for the video! So, when we purchased our home, this retaining wall was already done, but it lacks any drainage system. How would we go about fixing this?
Hi James, how old is the wall? If it has been there for a while and lets the water pass through the wall then i probaly wouldnt worry about if. If you want to put in drainage you are going to have to dig down behind the wall and install drainage as shown. I'm not sure how big your wall is but this could be a huge job.
Hi Marco, Ag pipe comes with the holes or slots already in it. If you have to drill them yourself i would suggest going to a Hardware store and having a look. I cant find anything that states the sizes and spacing of the holes. Or these pictures may help www.google.com.au/url?sa=i&url=https%3A%2F%2Fwww.alibaba.com%2Fproduct-detail%2FHDPE-Agricultural-Perforated-Subsoil-Drainage-Pipes_60765188155.html&psig=AOvVaw1j33Qwd0QjEmUf8epNCkTn&ust=1614317723230000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjL2KWohO8CFQAAAAAdAAAAABAL www.google.com.au/url?sa=i&url=https%3A%2F%2Fkennedys.net.au%2Fproduct%2Fpvc-slotted-drainage-pipe-90mm-x-6m%2F&psig=AOvVaw1j33Qwd0QjEmUf8epNCkTn&ust=1614317723230000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjL2KWohO8CFQAAAAAdAAAAABAY
I have a roughly 4 ft wood retaining wall in my backyard. I don’t think there’s any drain system behind it. I don’t know if I can dig all the way down to put the pipe along the bottom. Is there any value in digging as far down as I can - 2 ft, let’s say, and put aggregate and pipe there to move at least a little water away?
Hi Brett, if it is a timber wall there is a good chance that the water is getting throught the wall anyway. If this is the problem then you should be able to dig down the whole 4 ft if there is enough room behind the wall and put the Ag pipe on the footing of the Retaining wall. I guess 2ft would be better than nothing but the deeper the better.
@@Buildsum Yes. The water is definitely getting through - and I think the person who built it assumed that relieves all the pressure that is needed, but I think giving the water an outlet might be a better solution. And it is very mushy and not so bad to dig down - except for the fact it's 65 ft long.
this video is really helping me in my retaining wall project. Thank you! QUESTION: how high does the drainage aggregate need to go before filling the rest with backfill soil?
@@BuildsumI’ve seen some recommend “impervious soil” on top of the gravel. What do you think? And why don’t people just allow that gravel to be exposed? Concern it will get clogged without the fabric on top?
if the drainage pipe is on a slight angle for run off and one end is burried how do you cap up the burried end to stop sedament/gravel etc from runing into it ? cheers
Nice video! Is it better for it to have a slope from the middle outwards in both directions or from one end all the way continuously to the other end? Thanks!
Hey mate, question regarding the drainage. Do you need to have the ag pipe running along the retaining wall if you have weep holes along the wall? This is in clay type soil. The wall is 800mm at its highest sloping down to 200mm over 7 metres. Cheers.
Hi Mate, as long as the weepholes are sufficent to drain all the water that builds up and will no become blocked over the lifespan of the wall that should be ok.
Could somebody please advise? If I put the 'geo tech' fabric in place, won't this just stop all of the drainage? Is 'geo tech' the same as 'damp proofing'? Is 'geo tech' porous? I live in the UK - what is the local name for 'geo tech?' Many Thanks!
Hi Jean-Pierre, geotech fabric is porus, it will let the water through while holding back the soil. Here is a link to a UK website who supply GeoTextile products. geotextilemembranes.co.uk/ no recommendation just the first one i found on a google search. Hope this helps.
Q: should the requirement for the drainage and pipe be dependant on the height and weight of backfill? I'm only looking at backfilling a 40 - 60cm retaining wall.
If behind the retaining wall you planned to pave instead of having just a garden bed would backfilling with rubble on top of the blue metal stones be ok? Would the paver sink just behind the wall? Maybe you'd have to compact the blue metal stone before adding the rubble? Sorry confusing question
Hi Mate, the area behind the wall will be very likely to sink. You have to make sure that the Bluemetal is well compacted. Filling on the top of the Bluemetal is ok just make sure you have a good WeedMat or Geotextile fabric separating the two. Pavers would be better than concete as they will be more flexable and allow for more movement. It is also easier to pull them up and put in more fill if required.
@@Buildsum Hey mate, I really appreciate you replying and so quickly too. You sharing your knowledge with us is priceless! You won't believe how hard it is to get in contact with other tradies atm and get good advice! You have another subscriber now mate!
Blue metal is another name for crushed stone? (sharp edged). I should pull the geotex up over the top of the aggregate infill but then further up to the top of the wall, this prevents the top infill soil getting in between the wall and the geotex, also the soil will not go into the gaps between the blocks or sleepers of the wall. I'm currently building a retaining wall and this is helpful info, I have a good amount of reclaimed 10-20mm crushed stone from the garden path, after removing dirt from it by washing in a cement mixer this will be a decent aggregate for drainage I think.
@@Buildsum Actually not that bad, washing the agg. I did wash 3,5 cubic metres of gravel which came from my flat roof in about 8 hours, worth the effort considering the cost of disposal of roof gravel which is seen as chemical waste because of the tar used on old roofs. Now it is used in the concrete post feet and foundation for the wall.
Hello Buildsum, how far from the top would you put the gravel of a pressure treated 4x12 retaining wall (tallest 5' spot down to 2'). In other words how many inches of soil would you put on top of the gravel in the fabric barrier. Thank you!
Hi Anthony, it doesnt rely matter, you could even just use the same material as you are going to use to fill the rest of the wall just as long as it easy to level off.
Hi Anthony, you can get special fittings like this one www.bunnings.com.au/vinidex-50-x-25mm-grey-water-hose-adaptor_p4770262 however you could just cut the right sized hole in the 90mm pipe and push the ag pipe through the hole.
The black flexible pipe is cheaper, much cheaper, than schedule 40 pvc but, the black ABS plastic will be crushed under anywhere near that much rock. It might work for 8-12 months. That's all. You put perforated schedule 40 pvc pipe on the bottom, charge the customer more or make less profit, whatever, and then it will last for 150-450 years.
Hi Mate, Great educational video. One question, Is it OK to drill a series of multiple holes, across the thickness of wall, at the bottom of retainer wall and insert pipes to the other end for drainage? Or lay a series of pipes at the bottom of wall when building a new retainer wall? Thanks
Hi Gordon, you want a course sand with no clay content, the sand just makes it easier to level the bottom of the trench and it can also act to drian the water that doesen't make it into the Ag Pipe.
Great video thanks heaps. Rebuilding a wall that had zero drainage. Can I ask, does the Geofabric get clogged up? And are the AgiPipes with Socks any good? Cheers mate!
HI Lee, Thanks for your comments, I have not seen any evidence of the geotec fabric clogging and the agipipes with the socks would definitely be better than the ones without. Hope this helps
Hi Jimmy, the idea is to get the water around the wall rather than just build up behind it so even if you just let the Ag line run out the end of the wall that would work just as well.
Great video! I am building a pressure treated retaining wall. Do you recommend a moisture barrier in addition to the fabric and gravel? Should the moisture barrier be used for the entire back of the wall or just the part that is above the gravel? Thank you
Hi Virginia, i wouldnt put a moisture barrier in, IF the gravel was comprimsed or overwhelmed the water could still escape through the wall. If a barrier was in place the water would just build up and put pressure on the wall.
Just had a thought on this... would a paintable DPM product painted on the back of the sleepers be worth a shout? That way the soil (wet) side of the sleeper wall would have a water barrier but the water would also be able to naturally find its way through the joins/cracks/weep holes etc... love to hear someone's opinion on this.
Hi Nick, no not really the old wall may still provide some support and take some of the load off the new wall however it will take up a lot more room having it infront rather than removing the old one and replacing it.
Just starting now with a retaining wall (and not knowing muh to begin with) - this was a great lesson! Thank you! Do you prefer the 3/4 inch stone over the pea gravel? I've watched other videos and apparently pea gravel moves/rolls too easily and can compromise the structure much more so than the 3/4 inch stones that "lock" together?
Okay I have a I believe a unique question. I have a driveway and a retaining wall that's on my side the driveway is above and the retaining wall is holding back the driveway the driveway has now started to slide against the retaining wall I'm going to bump up the driveway which is the next door neighbors but there is virtually no room to backfill so I got to go straight up with the retaining wall and I do not want to undermine the driveway how do I do it and do I put drainage underneath there that perhaps May collapse is there a way of doing that?
Hi Conrad, Yes certainly a unique situation, and hard to resolve without disturbing the driveway. An option would be to use a retaining wall system that allows the water to pass through the wall without the need for drainage behind. A less desirable option would be to move the wall further onto your property to give you the room you need. Hope this helps
My attention would be on the shifting driveway or ground first. How about reinforcing the retaining wall first with steel pilings (or something similar) on your side, to prevent soil movement and also making your retaining wall stronger. Then build up on the retaining wall as necessary. I would think the soil will not hold much water assuming there is already a structure built on it. The drainage shown in the vid imho is ideal on new builds; if the sandpad is the open space on the property; and you have space for it.
that is really up to you as long as it doesn't end up in the neighbour's yard. You could run it into the stormwater system or just have it come back around to the front of the wall into a garden or onto the lawn
Instead of placing a drain pipe which over time will just fill with silt and roots, just make sure to have the correct amount & size of weep holes in the wall.
Running the geo fabric up the entire height of the wall is not the way it is done. You have geo fabric on the base of the wall and have a agg pipe encapsulated in at least 100mm of stone then wrap tha goe fabric around it. Then you fill with 300mm of drainage stone. Running fabric the full height of the wall would be labour intensive and an absolute pain to backfill a large wall!
Hi Mate, yes it is a pain on a large wall however if it is not done the drainage stone will eventually just fill up with soil and no longer drain the water away.
@@Buildsum I don't understand why the fabric (whether it installed up the full height of the wall or merely wraps the ag pipe and some aggregate) doesn't fill with silt and eventually transfer water pressure onto the wall. Am I missing something? I understand that fines will eventually clog drainage aggregate, so why won't fines clog the cloth as well? A top video either way. Thanks.
@@clarencecrowcarter Hi Clarence, the fabric provides a barrier that stops the fine particles of dirt filling up the pipe or the section of course fill behind the wall. Even when it is full of dirt It will still allow the water to pass through and then drain away so it doesn't fill up behind the wall and push it over. Hope this helps
C R You have it exactly right. The Geo fabric clogs in no time and the water pools. If you are in a Northern Climate, the wall is pushed to failure by ice.
Hi Mate, for a concrete retaining wall that is quite common, however there are plenty of other systems out there that are the same thickness the whole way up.
@@Buildsum oh, very interesting I thought it was a rule, concrete, blocks or rocks ....thicker underground, not sure I would trust such a thin wall to hold back the tonnage ...drained or otherwise as drainage can silt up and become ineffective over time
Eli Naghyoui HI Eli, An agg pipe would certainly help the water to get away from your wall quicker and give it somewhere to go rather than through your wall
Fuck my retaining wall doesn't have backfill.most retaining walls built 20 to 30 years ago in my country doesn't have backfill.so far the wall is still in place although there are some cracks.Is it possible to just cover the whole front of the wall with dirt?
I mean the repair cost a lot and my property is more than 30 years old.the wall is about 3 feet high.btw my neighbor's house have a retaining wall but it's not visible because they dump dirt in front of it and it covered the whole wall.i am planning to do the same because repair cost a lot.so far no problem at the neighbors house.he covered the whole the retaining wall about 20 years ago
Hi Martin The idea of retaining wall is to hold up the material behind it when it was too high to hold itself up. If you are not worried about the wall and the space that the additional dirt will take up then no problem. Remember that the dirt will have to able to support itself ua-cam.com/video/Lcyou2imKfQ/v-deo.html Hope this helps
Buildsum 'worried about the wall'? The wall won't collapse right?from the link you have given I believe the dirt that is being dumped in front of wall will prevent it from collapsing.plenty of space so space isn't an issue here btw
Hi Adam, yes i agree evern a solid wall should have weep holes. I guess it was a pour choice of words, what i meant was a wall that wont let the water pass through it like a solid concrete wall.
You could just make the original wall from concrete however this will not stop the build up of water and hydrostatic pressure. Even if the wall was strong enough not to break the pressure would eventually push it over. With the drain reliving this pressure you can use lighter weight materials to do the same job.
@@Buildsum what i mean is: between the retaining wall and soil, instead of filling it with usual dirt, sand, gravel etc, why not just fill it with conrete coz then the water wont trickle down to the bottom and you wont need a drain. what do u think?
I would NEVER use the black ABS plastic. With that much above it it will get CRUSHED! Use schedule 40 or 80 PVC - drill a lot of 0.5" dia holes about 15 degrees off bottom centerline (both sides) and be sure to use pea gravel on bottom layer and cover PVC pipe 80% with pea gravel. Be sure on the highest elevated portion of drainage pipe to add a clean out fitting. 95% of the time I see retaining wall or foundation drain issues the installer used that WORTHLESS ABS stuff with no clean out fitting.
I concur. My husband and I have constructed many retaining walls in a variety of soil conditions. Abandoned the use of ABS in favour of perforated PVC in all wall drainage systems. PVC manufacturers also have end caps and other fittings to accommodate clean outs and exterior drainage through the wall. A wide variety of Geotextile fabrics are available to handle drainage/soil separation from drain rock.
![How to Build A TIMBER Retaining Wall [What's Behind the Wall?]](/img/n.gif)
Thank you for passing on all of this knowledge. As someone starting out their career in this industry, these videos are a Godsend
Thanks Mate, I''m glad you like them.
This book is a comprehensive guide for anyone who wants to build a second unit on their property. ua-cam.com/users/postUgkxzaRUJNcbypw-fRBDbqqz43ULIa-1EGP- It showcases various types of houses, such as garage apartments, with photos, videos, and floor plans. The book provides the square footage and the dimensions of each house, as well as the option to order the plans or customize them according to your preferences. You can choose from a range of styles, from ultra modern to cottages and A frame lake houses. The book also offers suggestions for sheds, pool houses, and office studio buildings. This book is an ideal resource for the aspiring home designer.
people like you who is willing to share the experience and skills making this world great!!! you are an excellent guys!
David Yi Thanks David I'm glad you like the videos
⁵
Thanks m8! ❤Best I could find, the rest were out there! One even recomended AGAINST ag- pipe, and pushed skinny rigid pvc pipe, dirt backfilled🤣 no sight of gravel or fabric...what the heck!? Thanks for your sanity and simple to understand vid xx
The best YT tutorial on this subject. Thanks so much.
Thanks mate, Glad it was helpful!
Brilliant. Thought this was a question too specific for anyone to have an answer for.
Thanks Mate, good to hear that it is useful.
great video thank you, I am a DIY amateur looking to build my first retaining wall This video was quick and taught me a few things.
Literally exactly what i was looking for. thank you for this mate, spot on.
Hi Andrew, Glad you like it, hope it helps.
Andrew same made so much sense
mega spray hell yeah mate!!!
Top shelf video, thanks for the upload. I had a retaining wall built 6 months ago and a tradie who recently worked on my property noticed it's already atlease 10 mm offline. Either he didn't put a drainage pipe down or not enough of aggi or gravel mix. In short I am getting the guy in again to 'please explain'
Thanks Mate, I'm glad it was helpful!
In the process of filling behind my wall and not sure how
much gravel. The wall is 1200mm high so from your video I will continue to fill
with gravel. Will add geo fabric as a separation between soil and gravel. Thank
you for your video, answered my question about how much gravel. Mt Colah, NSW
Hi, Mate, good to hear that you found this video useful, thanks for your comment.
Well presented, well explained. Thank you my Friend, this has really helped me to understand how the retaining wall works 👍🏽👍🏽👍🏽
Hi mate, thanks, I'm glad it was helpful!
I would geo mesh every 2 ft
Brilliant, great video, straight to the point. Would this work exactly the same if the retaining wall was the basement of a house?
Hi Mate, with a basement you would have to have a waterproof membrane on the outside of the wall a well. Hope this helps.
@@Buildsum great, thanks for the reply
My retaining wall failed exactly where the previous owner added geo fabric. Over a short period of time, the fabric gets clogged by dirt and water begins to accumulate on top and behind rather than flow through the porous wall which is what the wall was designed to do.
Could somebody please advise?
If I put the 'geo tech' fabric in place, won't this just stop all of the drainage? Is 'geo tech' the same as 'damp proofing'? Is 'geo tech' porous? I live in the UK - what is the local name for 'geo tech?' Many Thanks!
@@virabadrasana That’s exactly the same thing I wanted to know and just asked the same question myself lol 🤷♂️
Did you ever find out the answer to this question?
@@CyberWolfVR This video mentions some issues that can arise from clogged fabric ua-cam.com/video/yKp-u5Gr2QA/v-deo.html
If you have a CLAY type soil DON'T put geofabric vertically. It will get clogged up. Hydrostatic pressure will build up behind the clogged fabric. This will push against the drainage stone. The drainage stone will in turn push againt the wall. The wall will then belly and potentially blow out. For CLAY soils only put the geofabric horizontally over the drainage rock, don't run it vertically down the side between the CLAY soil and the drainage stone.
thank you so much now i know why the rain waters keeps coming through the wall. I didnt put enough gravel and too much old fill. damn should of research more before filling it :(
Hi Shin, thanks for your comment, yes a few minutes research is always worth the effort.
To my knowledge putting an ag pipe directly on sand necessitates the use of a socked ag pipe or else the sand will just migrate into the Ag over time (and wash away). Not sure why you're not just putting the Ag on 100mm of the same drainage aggregate instead (and using geotech behind wall as discussed in vid)
Hi Mate, the bed of sand just allows you to easily get the slope you will need on the pipe. You could use the same material as the drainage aggregate if you like.
Great video mate. I’ve searched to see if you have been asked this already but I couldn’t see it.
Would it be beneficial to lay a plastic sheet behind the wall, between it and the blue metal to prevent water coming through it?
Hi Mate, no, unless you have some reason for not letting water through other than looks. You really want the water to escape so it doesnt build up presure behind your wall.
@@Buildsum that makes total sense. I have to replace a retaining wall under my house, so I think to help reduce the amount of water coming through I may run 2 Agi-pipes with a plastic sheet to help reduce water coming through. I will take the extra weight from water buildup into serious consideration when choosing the material sizes etc.
Thanks for the reply and great info.
I’m building an 8 foot long retaining wall coming out from my house. The wall will step down gradually to match the ground that slopes away from the house. My wall will be at its highest point about 2 1/2’ tall at the house and will step down over that 8 feet to about 1 foot tall.
My trench is 10” wide and my block is 7” wide. I’ve put down 5” of Class 5 rock and packed it down then have about half to 1” an inch of sand on top of that to level it off nicely.
I’ll put gravel and fabric between the wall and dirt like you show here. Since the ground on the outside of the wall slopes so quickly over 8’ so I need the drainage tubing?
Thanks
Hi Mate, yes i would still be putting the ag pipe in.
@@Buildsum thanks
thanks for the tips ...working on a retaining wall now!
We have a high retaining wall in our back garden (about 8ft) that holds back our neighbours garden which is alot higher than ours. It does have small drainage pipes at the bottom of the wall, however the wall is constantly wet in patches. Could this be because the backfill has mixed and there is now soil directly behind the wall? The wall was built by our house builder so not sure what they have done behind it 😅
Hi, yes that could be the cause or a blocked drainage hole.
Thank you so much for this video. Very informative
Thanks Mate.
Sorry for my question you might not see it but at the moment I am working on a retaining wall system for stone load-bearing walls (two floors in direct contact with the river ,However, I am not sure if I need to use the pipes and what the purpose of it in that case and how thick my wall need to be in order to hold the structure
Hi mate, sounds like you need to get your wall designed by a Structural Engineer or similar due to the extreame nature of your situation.
Hey quick question what can you do if the dirt has been washed out from below the wall and now the wall is on the air and dirt is still washing below it, this is happening to me right now at the moment half of my garden has washed out from below and my wall already fell also it is still raining so my garden is still being washed out i tried making a retention wall but dirt is still washing into it and it is dangerous please can you give me a suggestion or something thanks...
Hi Miguel, there is not much you can do until the rain stops, if the water and soil is running under the wall it sounds like you should dig in a concrete footing that runs along the bottom of the wall. Then you will have to dig out behind the wall like shown in the video and install the Ag pipe and the well draining material. Unfortunately it sounds like you have go a real mess on your hands however you may have to make some more in order to be a wall that will do the job that you need it to. Hope this helps.
Would fiberglass mat work instead of "geo tech" mat? In Vietnam over here, we don't have fancy construction materials. Or could that clog up and defeat the purpose of the draining layer, as mentioned in another comment?
Also: no weep holes?
Hi Mate, i guess it would be better than nothing however I have never seen or heard of it being used so not sure how it would perform. sorry.
Dont know about putting a sand bed but good presentation 👌🏻
I've got a house where the brickwork has been built into the hillside without any waterproofing or drainage, and the subfloor is flooding behind it. Plumber had a go but only went halfway down so water is penetrating underneath.
Would this technique be the same for a structural house wall, maybe just with waterproofing on the house side?
Hi Robert, yes you would need to do the same thing and waterproof the outside of the wall as well.
Thanks for the video! So, when we purchased our home, this retaining wall was already done, but it lacks any drainage system. How would we go about fixing this?
Hi James, how old is the wall? If it has been there for a while and lets the water pass through the wall then i probaly wouldnt worry about if. If you want to put in drainage you are going to have to dig down behind the wall and install drainage as shown. I'm not sure how big your wall is but this could be a huge job.
Gotta make wholes on top of pipe right for water to go into pipe? How big and how apart are the holes and do I put them on side or top of pipe?
Hi Marco, Ag pipe comes with the holes or slots already in it. If you have to drill them yourself i would suggest going to a Hardware store and having a look. I cant find anything that states the sizes and spacing of the holes. Or these pictures may help
www.google.com.au/url?sa=i&url=https%3A%2F%2Fwww.alibaba.com%2Fproduct-detail%2FHDPE-Agricultural-Perforated-Subsoil-Drainage-Pipes_60765188155.html&psig=AOvVaw1j33Qwd0QjEmUf8epNCkTn&ust=1614317723230000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjL2KWohO8CFQAAAAAdAAAAABAL
www.google.com.au/url?sa=i&url=https%3A%2F%2Fkennedys.net.au%2Fproduct%2Fpvc-slotted-drainage-pipe-90mm-x-6m%2F&psig=AOvVaw1j33Qwd0QjEmUf8epNCkTn&ust=1614317723230000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjL2KWohO8CFQAAAAAdAAAAABAY
@@Buildsum thank u
I have a roughly 4 ft wood retaining wall in my backyard. I don’t think there’s any drain system behind it. I don’t know if I can dig all the way down to put the pipe along the bottom. Is there any value in digging as far down as I can - 2 ft, let’s say, and put aggregate and pipe there to move at least a little water away?
Hi Brett, if it is a timber wall there is a good chance that the water is getting throught the wall anyway. If this is the problem then you should be able to dig down the whole 4 ft if there is enough room behind the wall and put the Ag pipe on the footing of the Retaining wall. I guess 2ft would be better than nothing but the deeper the better.
@@Buildsum Yes. The water is definitely getting through - and I think the person who built it assumed that relieves all the pressure that is needed, but I think giving the water an outlet might be a better solution. And it is very mushy and not so bad to dig down - except for the fact it's 65 ft long.
this video is really helping me in my retaining wall project. Thank you! QUESTION: how high does the drainage aggregate need to go before filling the rest with backfill soil?
Hi mate, the whole way up, you just need enough soil on top to let the grass grow.
@@BuildsumI’ve seen some recommend “impervious soil” on top of the gravel. What do you think? And why don’t people just allow that gravel to be exposed? Concern it will get clogged without the fabric on top?
if the drainage pipe is on a slight angle for run off and one end is burried how do you cap up the burried end to stop sedament/gravel etc from runing into it ? cheers
Hi, I would just make sure that the end is covered with the geotec fabric (the sock that the ag pipe is covered in) before you add the stone
Hi Buildsum,
Would you recommend this to help drain around foundations of a house?
Hi Mate, yes that would work.
Great video, should the ag pipe have a slight fall / slope to drain effectively?
Thanks Andrew, Yes a slight fall will help
Nice video! Is it better for it to have a slope from the middle outwards in both directions or from one end all the way continuously to the other end? Thanks!
Hey mate, question regarding the drainage. Do you need to have the ag pipe running along the retaining wall if you have weep holes along the wall? This is in clay type soil. The wall is 800mm at its highest sloping down to 200mm over 7 metres. Cheers.
Hi Mate, as long as the weepholes are sufficent to drain all the water that builds up and will no become blocked over the lifespan of the wall that should be ok.
@@Buildsum Thank you kindly good sir 👍🏻
Could somebody please advise?
If I put the 'geo tech' fabric in place, won't this just stop all of the drainage? Is 'geo tech' the same as 'damp proofing'? Is 'geo tech' porous? I live in the UK - what is the local name for 'geo tech?' Many Thanks!
Hi Jean-Pierre, geotech fabric is porus, it will let the water through while holding back the soil. Here is a link to a UK website who supply GeoTextile products.
geotextilemembranes.co.uk/
no recommendation just the first one i found on a google search.
Hope this helps.
Wait, how does water get through the wall of the plastic pipe? This has confused me for ages. Doing a DIY project now.
Hi Mate, the ag or agi pipe has small holes in it that allows the water to enter the pipe.
Forget the pipe! How does water even drain into the gravel bed if it’s surrounded by the geo tech? lol 🤷♂️
Q: should the requirement for the drainage and pipe be dependant on the height and weight of backfill? I'm only looking at backfilling a 40 - 60cm retaining wall.
Hi Mate, i would put it in regardless of the height of the wall.
@@Buildsum thank you.
If behind the retaining wall you planned to pave instead of having just a garden bed would backfilling with rubble on top of the blue metal stones be ok? Would the paver sink just behind the wall? Maybe you'd have to compact the blue metal stone before adding the rubble?
Sorry confusing question
Hi Mate, the area behind the wall will be very likely to sink. You have to make sure that the Bluemetal is well compacted. Filling on the top of the Bluemetal is ok just make sure you have a good WeedMat or Geotextile fabric separating the two. Pavers would be better than concete as they will be more flexable and allow for more movement. It is also easier to pull them up and put in more fill if required.
@@Buildsum Hey mate, I really appreciate you replying and so quickly too. You sharing your knowledge with us is priceless! You won't believe how hard it is to get in contact with other tradies atm and get good advice! You have another subscriber now mate!
Thanks Mate, Welcome aboard.
How wide would you make the drainage rock on a 3.5 m high wall using 70/40 mix
200 - 300mm wide will do the trick.
@@Buildsum yeh awesome thanks for that. I went 400 -600 wide had the extra material available
Blue metal is another name for crushed stone? (sharp edged).
I should pull the geotex up over the top of the aggregate infill but then further up to the top of the wall, this prevents the top infill soil getting in between the wall and the geotex, also the soil will not go into the gaps between the blocks or sleepers of the wall.
I'm currently building a retaining wall and this is helpful info, I have a good amount of reclaimed 10-20mm crushed stone from the garden path, after removing dirt from it by washing in a cement mixer this will be a decent aggregate for drainage I think.
Hi Tom, Yeah, that all should be good, going to be a lot of work washing that agg though.
@@Buildsum Actually not that bad, washing the agg.
I did wash 3,5 cubic metres of gravel which came from my flat roof in about 8 hours, worth the effort considering the cost of disposal of roof gravel which is seen as chemical waste because of the tar used on old roofs. Now it is used in the concrete post feet and foundation for the wall.
Hello Buildsum, how far from the top would you put the gravel of a pressure treated 4x12 retaining wall (tallest 5' spot down to 2'). In other words how many inches of soil would you put on top of the gravel in the fabric barrier. Thank you!
Hi Virginia, just just need enough soil on top to keep the grass alive. The more gravel the better.
Hello, can you tell what sand would be suitable to use for the first layer
Hi Anthony, it doesnt rely matter, you could even just use the same material as you are going to use to fill the rest of the wall just as long as it easy to level off.
@@Buildsum thanks much appreciated, also how do to connect a 50mm Perforated Land Drain Pipe x 50m to a 50mm 90˚ Land Drainage Tee Junction..thanks
Hi Anthony, you can get special fittings like this one
www.bunnings.com.au/vinidex-50-x-25mm-grey-water-hose-adaptor_p4770262
however you could just cut the right sized hole in the 90mm pipe and push the ag pipe through the hole.
Thanks for thr advice and tips 👍
The black flexible pipe is cheaper, much cheaper, than schedule 40 pvc but, the black ABS plastic will be crushed under anywhere near that much rock. It might work for 8-12 months. That's all. You put perforated schedule 40 pvc pipe on the bottom, charge the customer more or make less profit, whatever, and then it will last for 150-450 years.
Thanks, Max, good advice.
Hi Mate,
Great educational video. One question, Is it OK to drill a series of multiple holes, across the thickness of wall, at the bottom of retainer wall and insert pipes to the other end for drainage?
Or lay a series of pipes at the bottom of wall when building a new retainer wall? Thanks
Hi Mate, sure anything to allow the water to get away as long as you are not weakening the wall at that point.
@@Buildsum Thanks. Much appreciated.
Simple explanation but very informative. What type of sand do you use and do you compact it?
Hi Gordon, you want a course sand with no clay content, the sand just makes it easier to level the bottom of the trench and it can also act to drian the water that doesen't make it into the Ag Pipe.
2:51 If you have the geo tech on top and the side, how does water even get into the gravel and down to the drain pipe? 🤷♂️
Hi Mate, the Geotech fabric is design to allow water to pass through it while filtering out the soil so the water will still get to the pipe.
@@Buildsum Ah ok, great thanks 👍🏼
excellent video. thank you.
Thanks Mate, Glad you liked it!
Great video thanks heaps. Rebuilding a wall that had zero drainage. Can I ask, does the Geofabric get clogged up? And are the AgiPipes with Socks any good? Cheers mate!
HI Lee, Thanks for your comments, I have not seen any evidence of the geotec fabric clogging and the
agipipes with the socks would definitely be better than the ones without.
Hope this helps
I don’t have a drain to connect it to anywhere what are my options please?
Hi Jimmy, the idea is to get the water around the wall rather than just build up behind it so even if you just let the Ag line run out the end of the wall that would work just as well.
My footings extend to under the agg pipe area. What do you advise in this situation?
Hi Mate, that's fine, just sit the ag pipe on top of the footing using the sand to give is some fall.
@@Buildsum Thank you mate for a prompt reply. Much appreciated. Btw, Loved the clarity of your video.
Thanks Mate, I'm glad you like them, thanks for your comment.
@@Buildsum I have some bricky sand left over from brick laying. Would it be suitable to use for creating slope away from the restating wall? TIA
@@JimmyjimmyJimmyjimmy-ih3yd yeah mate that will work fine
Great video! I am building a pressure treated retaining wall. Do you recommend a moisture barrier in addition to the fabric and gravel? Should the moisture barrier be used for the entire back of the wall or just the part that is above the gravel? Thank you
Hi Virginia, i wouldnt put a moisture barrier in, IF the gravel was comprimsed or overwhelmed the water could still escape through the wall. If a barrier was in place the water would just build up and put pressure on the wall.
@@Buildsum this is the answer I have trawled the Internet for weeks to find... Nice one bro...! 🤜🤛
Just had a thought on this... would a paintable DPM product painted on the back of the sleepers be worth a shout? That way the soil (wet) side of the sleeper wall would have a water barrier but the water would also be able to naturally find its way through the joins/cracks/weep holes etc... love to hear someone's opinion on this.
thanks mate , great vid.. bad idea to build a concrete sleeper wall in front of an old treated timber one buildsum?
Hi Nick, no not really the old wall may still provide some support and take some of the load off the new wall however it will take up a lot more room having it infront rather than removing the old one and replacing it.
Did you do it? I am also thinking of adding a concrete or stone retaining wall in front of existing timber wall..
Good job mate
Thanks Mate.
How about using a Capiphon system much better the agipipe
Hi Akram, im not sure that that would be nessecary the more complicated you make the system the more chances of something going wrong.
Great video, well done and very helpful!
Thanks Stephen, Glad you like it
Hey Buildsum, also just wanted to comment video was really good!
What drainage material do you recommend these days? Thanks!
Hi Mate, blue metal is still the normal but recycled crushed concrete may be a cheaper option these days.
@@Buildsum legend thanks mate
Just starting now with a retaining wall (and not knowing muh to begin with) - this was a great lesson! Thank you!
Do you prefer the 3/4 inch stone over the pea gravel? I've watched other videos and apparently pea gravel moves/rolls too easily and can compromise the structure much more so than the 3/4 inch stones that "lock" together?
Hi Becly
I would prefer 10-20mm blue metal or recycled concrete.
wont the ag pipe just get crushed by the gravel backfill
Hi Mate, no it is designed to withstand these loads.
Okay I have a I believe a unique question. I have a driveway and a retaining wall that's on my side the driveway is above and the retaining wall is holding back the driveway the driveway has now started to slide against the retaining wall I'm going to bump up the driveway which is the next door neighbors but there is virtually no room to backfill so I got to go straight up with the retaining wall and I do not want to undermine the driveway how do I do it and do I put drainage underneath there that perhaps May collapse is there a way of doing that?
Hi Conrad, Yes certainly a unique situation, and hard to resolve without disturbing the driveway. An option would be to use a retaining wall system that allows the water to pass through the wall without the need for drainage behind. A less desirable option would be to move the wall further onto your property to give you the room you need.
Hope this helps
My attention would be on the shifting driveway or ground first. How about reinforcing the retaining wall first with steel pilings (or something similar) on your side, to prevent soil movement and also making your retaining wall stronger. Then build up on the retaining wall as necessary. I would think the soil will not hold much water assuming there is already a structure built on it.
The drainage shown in the vid imho is ideal on new builds; if the sandpad is the open space on the property; and you have space for it.
Yep, bewdy many thanks.
Very helpful! Thank you!
Thanks Mate, I'm glad it was helpful!
Great video...Is the blue metal compacted on top of ag pipe. If so i assume it be compacted simultaneously with sand fill.... thanks again john
+John Charles Hi John No there is no need to compact the blue metal
Thanks. Handy video.
Thanks Sam.
Where will the collected water be drained off to?
that is really up to you as long as it doesn't end up in the neighbour's yard. You could run it into the stormwater system or just have it come back around to the front of the wall into a garden or onto the lawn
Best video. Thank you.
Thanks Mate.
Very well explained
Thanks Christian.
Very helpful., Thank you.
the holes are supposed to be on the bottom. water builds up and flows up into the pipe. not down into it.
Hi Mate, the holes in Agg pipe are generally located all around the pipe so the water can enter from anywhere
Instead of placing a drain pipe which over time will just fill with silt and roots, just make sure to have the correct amount & size of weep holes in the wall.
Is there a formula for this? As far as how many holes/size per square foot of wall?
Running the geo fabric up the entire height of the wall is not the way it is done. You have geo fabric on the base of the wall and have a agg pipe encapsulated in at least 100mm of stone then wrap tha goe fabric around it. Then you fill with 300mm of drainage stone. Running fabric the full height of the wall would be labour intensive and an absolute pain to backfill a large wall!
Hi Mate, yes it is a pain on a large wall however if it is not done the drainage stone will eventually just fill up with soil and no longer drain the water away.
@@Buildsum I don't understand why the fabric (whether it installed up the full height of the wall or merely wraps the ag pipe and some aggregate) doesn't fill with silt and eventually transfer water pressure onto the wall. Am I missing something? I understand that fines will eventually clog drainage aggregate, so why won't fines clog the cloth as well?
A top video either way. Thanks.
@@clarencecrowcarter Hi Clarence, the fabric provides a barrier that stops the fine particles of dirt filling up the pipe or the section of course fill behind the wall. Even when it is full of dirt It will still allow the water to pass through and then drain away so it doesn't fill up behind the wall and push it over.
Hope this helps
C R You have it exactly right. The Geo fabric clogs in no time and the water pools. If you are in a Northern Climate, the wall is pushed to failure by ice.
@@clarencecrowcarter C R you are correct. Don't use filter fabric vertically if you have a clay soil. It will clog up and contribute to wall failure.
Video is distorted. What happened?
Hi Mate, it seems ok now on my end so not sure.
Retaining walls should be much thicker underground then taper up to the final course..or be too weak
Hi Mate, for a concrete retaining wall that is quite common, however there are plenty of other systems out there that are the same thickness the whole way up.
@@Buildsum oh, very interesting
I thought it was a rule, concrete, blocks or rocks ....thicker underground, not sure I would trust such a thin wall to hold back the tonnage ...drained or otherwise as drainage can silt up and become ineffective over time
Great video.
Thanks Andrew
Glad you like it
Spot. On mate
Thanks, Dene.
Thanks for the video
No problem, glad you like it.
hello i have built similar wall but added blue metal. should i have placed an agg pipe. water is leaking through my wall
Eli Naghyoui HI Eli, An agg pipe would certainly help the water to get away from your wall quicker and give it somewhere to go rather than through your wall
Thank you
Thanks, Mate.
Fuck my retaining wall doesn't have backfill.most retaining walls built 20 to 30 years ago in my country doesn't have backfill.so far the wall is still in place although there are some cracks.Is it possible to just cover the whole front of the wall with dirt?
I mean the repair cost a lot and my property is more than 30 years old.the wall is about 3 feet high.btw my neighbor's house have a retaining wall but it's not visible because they dump dirt in front of it and it covered the whole wall.i am planning to do the same because repair cost a lot.so far no problem at the neighbors house.he covered the whole the retaining wall about 20 years ago
Hi Martin
The idea of retaining wall is to hold up the material behind it when it was too high to hold itself up. If you are not worried about the wall and the space that the additional dirt will take up then no problem. Remember that the dirt will have to able to support itself
ua-cam.com/video/Lcyou2imKfQ/v-deo.html
Hope this helps
Buildsum thanks for the video
Buildsum 'worried about the wall'? The wall won't collapse right?from the link you have given I believe the dirt that is being dumped in front of wall will prevent it from collapsing.plenty of space so space isn't an issue here btw
Hi Martin
No, the wall won't collapse, as you say the dirt in front of it will help. I meant if you are not worried about covering the wall.
Disagree with the wall not allowing the water to pass through, retaining walls should still have weep vents at the bottom
Hi Adam, yes i agree evern a solid wall should have weep holes. I guess it was a pour choice of words, what i meant was a wall that wont let the water pass through it like a solid concrete wall.
@@Buildsum I see, great video, clear and informative. Just what I was looking for:)
finally...thank you
Thanks, Marg, Glad you like it.
Why cant u just fill it with concrete? Then u wont need a drain.
You could just make the original wall from concrete however this will not stop the build up of water and hydrostatic pressure. Even if the wall was strong enough not to break the pressure would eventually push it over. With the drain reliving this pressure you can use lighter weight materials to do the same job.
@@Buildsum what i mean is: between the retaining wall and soil, instead of filling it with usual dirt, sand, gravel etc, why not just fill it with conrete coz then the water wont trickle down to the bottom and you wont need a drain. what do u think?
Hi, as per my previous comment you still need to get the water out from behind the wall, filling it with concrete is not going to help in any way.
I would NEVER use the black ABS plastic. With that much above it it will get CRUSHED! Use schedule 40 or 80 PVC - drill a lot of 0.5" dia holes about 15 degrees off bottom centerline (both sides) and be sure to use pea gravel on bottom layer and cover PVC pipe 80% with pea gravel. Be sure on the highest elevated portion of drainage pipe to add a clean out fitting.
95% of the time I see retaining wall or foundation drain issues the installer used that WORTHLESS ABS stuff with no clean out fitting.
HI Mate, thanks for your comments, good to know
I concur. My husband and I have constructed many retaining walls in a variety of soil conditions. Abandoned the use of ABS in favour of perforated PVC in all wall drainage systems. PVC manufacturers also have end caps and other fittings to accommodate clean outs and exterior drainage through the wall. A wide variety of Geotextile fabrics are available to handle drainage/soil separation from drain rock.
Awesome
Thanks, Jasmine, glad you like it.
No dead men ?
They're buried under neighbor's add-on porch.
Great stuff ,wasted my time with other uploads yours
Thanks Andy, glad you like it.
Thank you