The Best Attic for a Hot/Humid Climate
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- Опубліковано 23 лип 2024
- In this video I'm reviewing all the reasons you should build conditioned attics in hot/humid climates. I'm joined by John Umphress of the Austin Energy Green Building Program. Matt Risinger
Fantastic video Matt! New subscriber man, and I love your ideals and values as you go about your process. You've shown you're a grade above when it comes to the thought process of building your homes, and it's certainly appreciated! Keep it up brother, looking forward to seeing more content! A Houston resident, but the value of your videos translates so well across the Texas climate. Cheers!
@clintsmith96 We sprayed 7.5" of open cell on the underside and we used 3/4" of rigid polyiso on top of the roof. Closed cell is certainly an option but it's more expensive and I don't think it's worth the cost for this application. I also like open cell foam for roofs as it's pourous. If you ever had a roof leak the water would drain through the foam. Closed cell foam would trap the water and rot the roof before you knew you had trouble. -Matt Risinger
doesn't the open cell foam create a mold play ground in the attic since it's not conditioned space? I'm looking at options for florida
This is a conditioned attic assembly. That is why it has such a low temperature.
@@Bward216 It can, but have to make sure you have a good air and water barrier. He also added polyiso on the roof to keep the some of the dewpoint out of the insulation and more so at the roof deck, very very very unlikely to have mold growth with the exterior insulation on top.
Exactly what I will be doing for my new build in the Phoenix area.
You're a fucking imbecile!
vapor drive and humid hot air WILL cause your framing members to rot
Great vid matt. love the work. Im also a builder who specialises in energy efficent home here in Australia and couldn't agree more about comfortable home with off the shelf products. Hi performance shouldnt be complicated. Cheers
So cool to hear from you Scott! Are you hot humid in Australia too? Never been. Would love to visit! Best, Matt
+Matt Risinger not where we are. im down south near melbourne. dry hot summers and cold winters. Very hot humid up north where we used to live. Plenty of chalangers in any climate though. We can get mould attack from the inside. Our building standards are very slack here with air tightness and condensation control.
Fantastic. Our house is generally comfortable except for the humidity.
Hi Matt, can you do a video on the difference between doing open cell foam under the roof and rigid foam under the rafters. Some UA-camrs are recommending air flow under the roof.
Hi Matt. Excellent videos you produce. I live in Houston and will build a home soon. Questions: What was the air temp outside and RH when you shot the video? Instead of using Polyiso, wouldn't Ice and Water Shield be a better product ... I am thinking about using Boral concrete tile. Did you also seal off any penetration from the floor below (such as wiring, etc.) for air leakage ... I wouldn't think so, because you would need some air flow. You are spot-on in regards to paying attention to dew point.
@HomeEnergyNow: Our cooling costs are much higher than that, I would guess the average 3000 sf house in Austin has a summertime electric bill above $400/month. We didn't spend $40k on those upgrades and they WILL pay for themselves. Those are rigid metal trunk lines with exterior insulation. We drop the last 10' or less in flex duct to quiet down the air stream. Remember that we already agreed to disagree on the fresh air system. -Matt Risinger
@HomeEnergyNow So, couple things don't add for me here. You're assuming energy costs will be constant in the future. I have no idea what electricity will cost in 5-10-30 years and that roof & insulation will still be going strong. Solar pencils out easily with Austin Energy rebates and Federal rebates, our 5Kw system was under $10k. The other factor you're not accounting for is comfort, this house will be much more comfortable for the owners than if I had built it to standard code. -Matt
We bought an older home and it has spray foam sprayed recently. The attic is very hot. They still have thrown in insulation. Do we need to keep it?
@@drdhruvang do you mean they still have blanket insulation on the attic floor? Our company removed it because it’s important to have some air exchange from the conditions space downstairs. I put a cheap dehumidifier in my large spray foam attic, and I tied the drain to our air conditioning units PVC condensate drain. Very easy and just enough to help keep the relative humidity low.
Hi love your work that you do for us what is the best way of insulating your home if you live in a warm climate
Great to see. I am thinking of spray foaming my attic here in central Florida. My question is, does the attic still need to be ventilated. As I am having roof redone as well. And need to know if I need to have them into vents etc. Thanks
To retrofit a current house that has hvac in attic, how do you address the condensation plane moving to the underside of roof sheathing when using spray foam on the roof deck to covert to a conditioned attic? Eastern NC here where dew points during the cooling season are regularly 70-78 degrees?
Matt - love the videos. Quick question: Do I need to have insulated ducts for the bathroom fans if my attic is a conditioned space? Or are uninsulated ducts OK since it's all the about the same temperature? Trying to avoid condensation issues inside and outside the ducts.
I live in Jax Fl. Why not just spray over the ceiling in your attic? And what about walls? I have T1-11 siding.
We have a 1:12 pitch vaulted framed rood from 1958. We have zero insulation in our roof. We live in hot and humid Central Florida. Out roofing is torch down roofing. We do not need a refoof job as it was installed in 2002. The roof is fine. Our problem is we don't have insulation. We have soffits with a 2 inch hole in each rafters bag and we have a 12 inch Whirlybird in the middle of our roof for taking out the heat. How should we go about insulating our ceiling? Thanks
Will the open cell foam insulation work for Maryland where it gets hot, but also cold? Also, with the foam against the sheathing, does the roof require sleepers and a 2nd layer of roof sheathing to keep the shingles cooler?
This might be a stupid question but here goes nothin’. If i were to insulate the roof with the open cell would the need for insulation on the ceiling be negated? I’m getting ready to build a house in Brandon, MS and I’m really interested in sealing the attic and the crawl space. Any info would be much appreciated. Thanks- Cam
I have an 851 sq foot cottage built in 1951 in hot and humid Beaufort, SC. The attic now has deteriorated insulation.My roof is tin and pitched. What type of insulation would you suggest? It has been 95 to 100 recently and attic is an oven.
Hi Matt, I have been watching a lot of your videos and I am a guy who wants to focus on Insulating homes the right way. I wished the builder did that properly or build homes the right way. Keep posting and educating. I was wondering if you do work in the Dallas area. I do have a question. In one of your videos where you remodel a home, the Insulations guys (True R Value guys) said not to put foam insulation in attic as you have Furnace up there and with Gas lines, you could have issues, but in this remodeled home, you have furnace and you have foam insulation. Can you provide your guidance? Also I heard that foam insulation can cause issues with Asphalt Shingles and your warranty can be voided. What are your thoughts there?
I leave in Augusta Georgia, and I would like to know how to contact someone that could insulate my attic. I am having issues with humidity in the house and it seems that is coming from the attic.
You can tell John is a smart guy. He was saying things along with Matt that I have been saying for years, especially the part about dew point being most important. Some people, mainly those up north assume people with a country accent are less intelligent, this is far from the truth.
Humidity is the killer. I would mention humidity to an HVAC guy about my window unit vs central unit. I had both and the window unit would drop the humidity. Of course the HVAC gave me a lecture. I was going on observation, which is pretty damn scientific.
Where do you get your panels from? Which company?
I live in a pier and beam 100 year old bungalow. We suffer from high humidity. Would doing something similar as in video solve our problem or would I need to address the open crawl space under the house as well?
Hi Matt,
I live in Converse, Texas just outside of San Antonio. I would like to install solar heating on my home, but I would like to have the home insulated properly before doing so. Our CPS bills are over 500 a month during the summer months. Do you do work outside of Austin? I watched your video and am very impressed with the job you do. I would like you or your company to give me an estimate on doing my home. If not, can you recommend a company here to have them come out and give me a fair assessment to get the job done properly?
Thanks again
James
What is the added cost of heating/cooling your home since you’re adding more square footage to the home? Also, do you have to buy a larger AC UNIT and or furnace to meet the needs of your attic as well as your home?
I'm in need of a completely new HVAC system our home was built in the 80's and we have a small poorly insulated attic. There is mold all within our air ducts we are located in Texas Hill Country so its hot in summer cold in winter we run off propane in winter. What would you suggest is the best and most efficient system for our home?
Hi Matt,
I Iive in the Atlanta, GA area. I had my attic roof insulated with open cell foam last year on my 3k sq. ft. two story home. After experiencing unusually high humidity levels of 66% in 2015, I recently added a whole-house humidifier/dehumidifier with two HEPA filters. We went ahead and replaced 8 duct runs in the attic that were suspected of leaking and we replaced two fiberglass insulated plenums with larger insulated metal plenums to further improve air quality.
I was informed by a different foam contractor that I should remove the existing pink insulation on my attic floor to allow the accumulating house gasses to rise from the upstairs rooms and into the attic. I was also told to install a mechanical fresh air duct to go directly into my dehumidifier which was not installed nor mentioned by my foam installation contractor. Is this necessary and if so, what is the best approach to install the fresh air duct - mechanical or electrical/auto?
Recently I noticed a leak in my roof in an upstairs bedroom. The entire roof was replaced 18 mos ago. This room has a cathedral ceiling whose sheetrock sits up under the roof rafters. I fear one of two issues:
1) The foam contractor failed to fill the rafter cavities above this ceiling thus creating a moisture laiden cavity because the air cannot escape since its path is cut off by foam blocking the other end. That may have created condensation that is leaking into the bedroom through the seams in the sheetrock.
2) The roofer did not adequately repair/replace the roofing in that portion of the roof.
- Thanks for your input. - Rick
Yes that insulation contractor was correct you should remove the insulation on the attic floor to allow the attic space to acclimate to the rest of the house temperature, and yes it is a good idea to introduce fresh air into your heating and cooling system. I don't know what type of humidifier you have but the unit Matt showed in the video has Provisions for fresh air intake ducts to be connected to it to introduce fresh air into the mechanical system. And your moisture problem does sound like lack of insulation to me hot meets cold condensing. If the roof was not spray foamed correctly and is hot and it's close to colder air condition sheetrock on the other side you very well could have condensation problems. I'm no Matt Risinger but I've been in the HVAC industry for almost 20 years and have a little understanding of this stuff.
@HomeEnergyNow That's rude.
Matt, if you spray foam the underside of Roof deck , how do you ventilate under the shingles? Have you furrred them out above the roof deck?
you should put air channels between the rafters before you cover it with spray foam from what I understand.
@@enkrypt3d just watched this video, answers your question. ua-cam.com/video/Ggk-ran6NKw/v-deo.html
Hi Matt. I have been watching your videos lately and agree with everything and have learned a lot. I have a few questions for you. I am in Florida, so much of the same weather and building issues you deal with, so here goes. 1) What do you do about termites with your stick built homes? 2) Can you do a video on FOAM as far as fire? 3) Can you give me some advise on making my shop easier to work in during our mostly hot and sticky weather? It is a 4 bay concrete block building with a truss structured roof and ZERO insulation. I have built a loft for storage and a wall dividing the two sides of the shop, so the side I am interested in cooling to be able to work is about 28' x 28' with (1) 16 foot overhead door and 2 cheap house style windows. I am a handicapped vet on a tiny check, so i need the best bang for my few bucks.
Hi Steve, I see you never received an answer to your question so I thought I might offer one of my own, my name is Daniel I work for Terminix pest control I am a outside sales and home inspector And I am located in West Palm Beach Florida. May I ask what part of Florida you live in? And Are you still looking to insulate your attic? For hot humid regions like South Florida EPA certified blown in cellulose is the best option For a few different reasons. 1st of all because it's so humid down here many houses can retain excess water That if left on absorbed can lead to wood rot and mold formations. Blown in cellulose is 89% recycled paper with A boric agent that makes it flame retardant And his the absolute best option for absorbing excess moisture because it acts very much like a sponge and redistributes excess water evenly across the entire service area of the insulation and eventually drys. The problem with closed or open cell spray on insulation is that it is not absorbent and can trap water between the Space between the insulation and wood it's attached to Which can cause Lead to would rot and mold growth as well it can possibly warp the surrounding wood. There is another risk which is fact that South Florida is ground 0 for dry wood and subterranean termites. Wet wood can extract these organisms And may conceal evidence of their presence for years. Treating for these organisms with spray on foam requires the removal of the insulation And reapplication afterward. Cellulose absorbs moisture and Aids in Keeping would dry which lowers the odds of termite activity and is easy to move out of the way if treated for termites is necessary And then can be simply moved back into place once complete. Cellulose insulation is also significantly rated much higher when it comes to Protecting against fire damage. Terminix is licensed To sell and install TAP cellulose insulation, It is an EPA certified high grade insulation that Has a specific characteristic that makes it stand apart from other cellulose insulation brands.TAP is an acronym for thermal, acoustic and pest control. Like other cellulose insulation brands. it has outstanding resistance to heat conduction Which typically saves customers between 20 and 30% monthly from their electricity costs. And is an affective Acoustic dampening Agent Making rooms insulated with it less likely to carry sound and Eco. And is treated with a boric acid dry pest control agent that will permanently keep pest insects away. Typically Terminix charges approximately a dollar per square foot to insulate with TAP , Which is less costly than insulating with spray foam insulation which can vary between a dollar to a dollar fifty per square foot depending if it is a open or closed cell spray foam. With the added benefit of the Immediate reduction in electricity costs, it will eventually will pay for itself.Terminix uses our own in house insulation crews to do this It does not use any sub contractor companies. I hope this answers your question and gives you insightful information to consider Best of luck with your project. have a great night
Is there a similar video for a Cold / dry Climates?
What happens if the big de-humidifier breaks? Does water condense on the ceiling of the attic then? I'm in Maryland and it's not always hot, but it's always humid. Big problems with black mold.
the humidifier is for the whole house not the Attic. You don't necessarily need it but it helps in keeping the house comfortable and cool by taking the humidity out of the air. The only reason it's in the Attic is because that's where the mechanical equipment is probably no basement area in the house. All the spray foam insulation on the underside of the roof is doing is keeping the heat out of the attic and keeping it at a reasonable temperature usually a few degrees higher than the house temperature, this way the space where the heating and air conditioning unit stays relatively cool in the summer time so the air conditioner can work more efficiently. The attic becomes somewhat conditioned space just like the downstairs levels therefore there should be no humidity problems. You're basically eliminating the Insulation that was on the floor of the attic between the attic and the lower level and raising it up a couple feet to the underside of the roof is all he is doing by spray foam in the underside of the roof. This way the lower floor temperatures of the house can travel up through the floor into the attic and maintain a lower temperature and the attic becomes conditioned space.
Matt Risinger I don't know if it snows at all in Austin, but here in northern Georgia it is hot and humid most of the year, but we can get a good snow or two ever other year maybe. With that insulation sprayed directly on the top of the roof with no ventilation are you not concerned for the possibility of ice damns and water leaking into the attic if you get the occasional snow storm? Thanks for the video!
+Kevin Kinnett For that you would need to install rafter baffling from the soffit vents up to the ridge/roof top vents to make sure that the roof and the sealed attic are still kept separate. I would also recommend a radiant barrier between the baffling and the foam.
snow/ice is not a concern in austin. I imagine you would be worrying about frozen pipes, electricity (outside electrical lines not insulated), driving on ice before worrying about the roof.
It only snow in the central and southern Texas area every 100 years or so and its a one day maybe 3 inches and then its gone in one to two days after that. And the last snow we had here in the Corpus Christi area was in 2004 so I think we're good for now lol
never say never
Jesus Matt, you look like a little kid. Hahaha. 10 years ago. Great content.
Why an open cell spray vs a closed cell spray insulation?
How about the best attic for two story house in California gets 100° that day with no ridge vent
I agree it's more efficient , but how much this cost to set up?
I need this guy to come to my house.
Wow! This guy John seem like he knows his stuff. He’s doing math and calculations for every answer that is given.
did you used to skateboard? did you go to McCallum high?
Hi Matt,
I’m considering having someone come to my home to
What R value & inches are sprayed on the underside of the roof?
Why not closed cell foam?
Thanks
Open cell is cheaper, R30 approximately.
@@jessewood3999 Also, vapor permeable
What's the up-charge? ...$25/gsf over "traditional" methods?
He looks so young!!!
Does the insulation ever shrink?
+Pete Linster nope
No.
What would be the approx. expense to upgrade a existing attic that measure's 1978 sq. ft. in a Coastal Home in Southeast Texas ?
MrSymbolic7 Hard to guess. Retro fits are very hard to guess. Access is the main issue. You'll need to talk to a contractor locally to know for sure. I wish you the best... Matt
We are a south Texas spray foam contractor. Estimate about $1.00 per square foot to remove the existing insulation and about $2.00 per square foot of foot deck for spray foam application. This is if the entire attic is accessible with a good roof pitch. Feel free to call us with any questions @ 361-960-0337. Thermal technology group LLC. Hope this helped.
I have A brand new ac unit. The handler in the attic and compressor outside. Its hot as hell in my room during the day. It doesnt stay as cool as my last house. It all pink insulation up in my attic,yuk. I hate getting that on me. What can I do to get my bedroom coll as the rest of my house?
First talk about how HOT it's been and will remain and then about how efficient the gas furnace is?? That would be great in the Northern part of USA.
That U-turn flex run that's smashed underneath the plenum looks like shit. Other than that: it's a nice looking install.
good shit mon
We need to vent the roof per Building Science Corp. And use rigid foam or rockwool, not spray foam!!!!
11 yrs later
I dislike variable speed DC fan motors as they cost 20 times what a 3 speed PSC motor runs and they invariably fail just outside a warranty period, I have replaced the DC motors with old school motors when customers discovered how much their indoor blower motor cost in comparison to the old PSC type fan motors, PLUS if they ever encounter resistance such as too many supply vents closed or dirty coil or filter they will burn out faster.
Dick, this is the fan and motor I have www.lowes.com/pd/Air-Vent-30-in-Aluminum-Single-Belt-Drive-Whole-House-Fan/3563350 it only has 2 speeds and it is not AC. What motor should I replace it with? I would rather have a motor that has infinitely variable speed.
Adam Savage really let himself go
All air conditioners are dehumidifiers. It is good that builders are making efforts to improve homes but if you properly size the AC you will control the humidity. Using a 900 sq/ft per ton heat load calculation may be undersizing the AC which would not remove sufficient humidity. Oversizing your AC will not remove sufficient humidity either, because it would drop the sensible heat too fast and cycle off before having time to remove the proper amount of humidity. Your dehumidifier is just another air conditioner which is controlled by a humidistat?
David Brewer In 1979 I was in the U.S. Navy stationed in Guam. Guam is very warm & extremely humid. I had a "window" air conditioner mounted in a sleeve in the concrete wall. It was a 240V model so I had a 50 amp relay with a 120V coil wired into the outlet & a lamp timer to control it. That way it would turn on an hour or so before I would normally get home. I also had a portable dehumidifier which I plugged directly into a timer. I kept the temperature at about 80°F & 40-45% relative humidity.
The A/C would start & I had the dehumidifier set to start an hour later. I had a box fan to circulate air to the bedroom. My normal electric consumption was about 20 KwH/day total (electric stove & water heater + climate control).
After a couple of months I decided to run a test; I shut off the dehumidifier. With the air conditioner providing all of the climate control I needed to lower the temperature to 76°F for the same comfort level. My electric consumption was about 40 KwH/day. So, by using the dehumidifier as an adjunct to the air conditioner I cut my electric bill in half.
One thing that I thought was pretty neat was, after the initial cool-down, the A/C would shut off, within 1 minute the dehumidifier would start. When the temperature went up the A/C would start & within a minute or two the dehumidifier would shut off. So, basically, the dehumidifier was keeping the humidity at a comfortable level and the A/C was keeping the temperature at a comfortable level (and also helping out with the humidity).
Paul Carver
Austin is not humid, it is dry. Come down to Houston and sweat like a mule.
Amen.
Try coming over to Mobile alabama. You can drown breathing the air going to check the mail
Your customers aren’t worried about saving money! They want the comfort which is what you keyed on. It cost money to condition that attic and solar panels lower the electric bill, but never pay for themselves over time. I guess if people pay for the solar with the total cost of the home, the lack of Econ feasibility of solar panels is hidden. The engineers that are potential home buyers will figure this out....
But you're not conditioning the space directly. Basements in Texas are very rare so duct work is almost always in the attic. Would you rather have 120 degree room above your conditioned space or something that is only 10 degrees warmer than your living space?
I tend to listen to people who've been doing something for 15 years over someone who got all their information ON LINE. wink wink. Guy on the left knows what he's talking about but this is simply over kill for bucks.
Genuine question. Where should the duct work go??? In FL it's standard to have ductwork in the attic. I've never seen a house any other way.
Get rid of all the crap in this attic and put in two large fans at either end to pull air through the attic! This isn't complicated!
Because having your ac handler sitting in a 100 degree room makes sense.
What a waste. Attics should be ventilated not sealed. Air conditioners, heaters, and duct work should not be in an attic. The living space should be heated and cooled not the attic.
Had me up until he said," American made." Only if the American quality got positive results. We can't even get our cars running correctly.