You have a steel house? Awsome!Originally Posted by Sparkkky
You have a steel house? Awsome!
I think you gotta be careful a bout how the exterior is finished if you're completely ceiling the interior walls. If that's the case I would imagine the exterior shouldn't be sealed with a house wrap at all. That would create an unventilated space between the interior sealed foam and the exterior and lead to condensation on the sheathing.
2017 Phoenix 819
2016 200ProXS, s/n 2B359849, Mod 1200P73BD
Don't mess with the foam insulation in the walls. To do it right use 2x6 construction with standard batt or blown-in insulation. The key is to achieve a thermal break on the exterior face of the studs by using an insulated sheathing board. Here's a link to the product data. This will out perform a foamed 2x4 wall by spades: http://www.huberwood.com/zipsystem/p...tem-rsheathing
2006 Ranger Z20 / 225HP Merc Pro XS
"ain't too smart.....but I'm always thinkin"
The key that foam has is air sealing, but the downside is moisture control. If your going to do foam what type is dependent on your climate zone and you will need to do some extra steps to make sure that moisture doesnt accumulate or leak into the foam. Southern zones 1 and 2 open cell is good along with whole home dehumidifiers that can keep the attic humidity in check. Combine that with a ice and water shield on the roof to keep the moisture drive from the sun from reaching the roof deck and you should be fine. In northern climates it gets a little trickier but can be done. Even closed cell will trap moisture in the roof decking. My suggestion is to do a rainscreen and vented metal roof if doing foam. Air seal the outside with a zip system or good peel and stick or spray on wrb. Then the rainscreen and vented roof can expel any moisture that ever gets thru and dry out. That's the simple explanation, building science goes way beyond that and there are many different levels of performance you can achieve but they also come at a cost. A lot depends on climate zone to how you would handle the vapor.
I suggest checking out Matt Risinger or Home performance on YouTube. They have a ton of videos on how these systems work and Matt has some great studies and test on different systems and how to combine them.
We are about to start building and here's what I plan on doing, based on cost of course so the roof may change. Regular 2×4 construction and osb sheathing with polywall spray wrap MVP and their other products to air seal and waterproof from the roof down. Use ice and watershield on the roof and do a vented metal roof. Also to do a vented rainscreen on the walls. To do the rainscreen and vent strips for the roof shouldn't add more than $1k of cost although the metal roof will be a pretty good bit more. You could always do another roof deck with venting in between and use the tech shield on the top one and do shingles. That would come out a little cheaper and add the benefit of the tech shield to your insulation values. Anyway, check out those YouTube channels and the building science websites, theres more information than you can handle lol
If you seal your house with foam, you will need to get a heat exchanger so that you get fresh air into your house. The air in your house is very polluted and you don't want to trap it in your house. Get some kind of air exchanger so that you get fresh air in the house.
We did foam in the walls and blown cellulose in the attic. 0 problems so far. Also, very low utility bills.
Foam insulation is a great thermal barrier but not a vapor barrier. Humidity will go up without other modifications. Air conditioners are de-humidifiers but with foam they won’t run long enough to de-humidify. This is why a/c sizing becomes more critical and you hear all these people on here talk about multi-zone or dehumidifiers etc. You have pay to play for efficiency sakes. Standard a/c will require a good integrated into your central system de-humidifier at a minimum. There are a lot of ways to accomplish some of this. Talk to reputable and knowledgeable HVAC company.
2014 Phoenix 721XP, 250 SHO, Bobs Action Jack, Dual Blades, 112 Ultrex, 2019 Lariat FX4 F150 Supercrew 4x4
I own an efficiency and solar company. Our new house is ALL foam with a silver standing seam roof. 17seer ac unit etc. I don't like large homes so our house is right at 1500sq feet of "living space." 72* ac setting middle of a south texas summer my utility bills are 114$ a month with a PLUG IN hybrid BMW X5. The foam is very efficient. We have solar going up shortly and that should zero us out other than $8/mo.
Every home I own going forward will have it. We have humidity mitigation stuff in place.
The suggestion to watch Matt Risinger is a good one. To me, there is no question that foam is superior and worth the cost but it comes with its own set of issues. If you just do everything else on the house like “normal” construction but then foam it, you’re probably going to have issues. It has to be part of an integrated system for the whole house. Including moisture management at the sources, HVAC including dehumidification and whole home heat and moisture recovery exchange ventilation, as well as roof and sheathing types and techniques of installation.
2022 Ranger Z520R, 2022 Mercury 250 ProXS 4s
Dual 16” Lowrance Live’s at console, 12” Live with Active Target, Garmin 8612 and Livescope, and Humminbird 12” Mega 360 at the bow
Lowrance Ghost TM
One needs a professional insulation and HVAC companies. Old HVAC rules do not apply with a total foam house. The house becomes a system. Heat exchanger, ac, exhaust vents, registers must be sized and install properly. My furnace/ air handler pulls outside air into the intake plenum. If a gas water heater and gas range is used it becomes even more critical to get it right. My house is one year old and is open cell foam including the roof, which makes a sealed conditioned attic. 3,000 sq ft living area with 20', 11', 10' 9' ceilings. I have a 3 or 3 1/2 Ton AC compressor. Last winter 6 hours in a 24 hour period was the longest the heat ran, usually 4 hours or less. In this brutal Arkansas heat and humidity 12 hours or less is the norm. I have no stale air, moisture problems or issues at all, but my builder builds many foam with conditioned attics and he and his subs know what they are doing.
Well there ya go.
I have been reading and reading and reading about this spray foam insulation. As far as my Shop/metal building goes, I have yet to have any of the builders tell me what method is "right" for my particular build.
Closed cell, open cell, they all say it's up to the customer.
Bullshit, one or the other is "RIGHT" for me. Closed cell on the walls if ya don't cover it because it's more durable. If yer gonna cover it then don't spend the money on Closed cell, open cell is fine "they say".
For the house>>>
To start with, foam is more expensive. So you have to spend more money to insulate, then you seal it up so good it can and will cause moisture problems, so then you spend more money to alleviate the moisture/stale/sick house syndrome.
And where we are building in DEEP East Texas, humidity is HIGH and a way of life. So my fresh air intake / exchanger thing-a-ma-bob is SUCKING IN MORE HUMIDITY. I just don't get it.
Where is the $$$ savings??
A vented metal roof is HIGH DOLLAR and at near 60 yrs old, my money will go to something else.
I ain't seen the Risinger dude ever discuss a foam application for my "area". He is yacking mostly about stuff around Austin and the Hill Country. TOTALLY different climate the East Texas.
"ain't too smart.....but I'm always thinkin"
You mad, bro?
2022 Ranger Z520R, 2022 Mercury 250 ProXS 4s
Dual 16” Lowrance Live’s at console, 12” Live with Active Target, Garmin 8612 and Livescope, and Humminbird 12” Mega 360 at the bow
Lowrance Ghost TM
We are building 4500 in S La, humidity is often 100% or very near. We put open cell on the roof decking and exterior walls. The exterior also has a foam board and wrap. The hvac is a 3 zone system with VFD compressor and will be installed this week as well connecting power to the house this week and powering up the AC. There is a significant difference between the outdoor temperature and the indooor temperature. However the indoor humidity is noticeably high. I plan to monitor the humidity inside the house as well as inside the attic.
oil tech.
I’ll be curious to hear your thoughts after some time with it.
The home builder we are talking with said that once the foam job is completed, they try to get the A/C running ASAP. I do not remember the exact reasoning.
"ain't too smart.....but I'm always thinkin"
No. Aggravated about not finding solid answers from the folks I’ve spoke too, other than how great it is and “that’s the best way to insulate these days”.
Just pointing out what you say is correct, and I can’t see the benefit with the cost and added equipment , and there’s also a chance the install goes south which could create more problems.
It’s a lot of money, it’s my last house and shop and I want to ensure I get it done right and want to know and understand how it’s done, right.
Last edited by Corkpuller; 08-09-2020 at 09:19 PM.
"ain't too smart.....but I'm always thinkin"
In this state you cant get a termite company to do your house because they cant see the wood work. Better check with your termite people.
It only saves you money, when you’re long gone, initial savings will take forever to pay themselves back. I prob said this when the thread was first started, but after working in a house that had hurricane damage & foam in it, I’d never have it. That crap had gallons & gallons of water trapped in it and it was just up there hiding for weeks until finally found.
Its prob fine in a metal building, I’m just not a fan of all the extras required for use in a residence.
Highly recommended
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