new construction - insulation

[Corkpuller]

pardon my typing skills, im left handed and only have use of my right, due to recent surgery.

lookin for hard facts / experience, concerning insulation on new construction. have got started on land clearing and road building to our little slice of heaven to where i'll be retiring to, and seeing my last sunset in deep east texas.

there seems to be a strong push towards this idea of making a house act like an igloo cooler with this closed cell foam insulation.
no ridge vents, no soffit vents. spray foam in walls and on roof decking i believe. no insulation laid between ceiling joists.

from what i understand, you dont seal the living area from the attic, the attic will attain close to the same temp as the living.

i just cant wrap my head around no attic ventitation in the east texas humidity. seems there would be a problem with mildew.

ive spoke with 2 different home owners and they claim its the cats ass. there are custom home builders in lufkin that see it the same........

any y'all have first hand knowledge about it all

[Bamaman]

I would have to refer you to the internet on that subject. You should be able to spot what gets sprayed online.

My buddy used to be an energy advisor at our regional power company. When he built onto his house, he used the spray on insulation on a 20' x 50' den. He has a small fireplace, and he says it'll burn you out in Winter. Sounds as if they're extremely efficient.

[Corkpuller]

I would have to refer you to the internet on that subject.

we're on the f'n internet bama!!!

ok you failed the test questions, next .

[Stompy]

I sprayed my house, best thing I ever did. 3400' of living area, 15' tall ceilings. 8 tons of AC and my electric bill has never been over $250.

[Stompy]

I have 2 vents in the attic which keeps the humidity out of the attic. It stays about 5 degrees warmer than inside the house. Also makes the house extremely quite, hard to hear anything going on outside. I would suggest open cell on the roof and closed cell on the walls. If you have open cell on the roof, and you one day have a leak it will leak straight down. If closed cell on the roof and you get a leak, it soaks it up like a sponge and makes it harder to find the leak. It also sure makes it nice working in the attic.

[Corkpuller]

What about needing to replace the roof.
Say I choose a metal roof and a panel needs replaced, or even a composition roof and some decking needs replaced.
Ain’t those parts covered with the foam.
Would you destroy a good part of the roof gettin it apart.

[Corkpuller]

Stomp what type of attic vents you have.

[CaymasMan250]

John hit the nail on the head. One thing I’d also consider Cork, on your exterior walls if using some type of osb etc I’d apply a roll on fluid applied weather barrier. Seal all sheathing joints and roll on the barrier then spray insulation in the inside. This application will seal it up really tight. If it’s something you are interested in I can help you with that, we do it everyday.

[Stompy]

My roof is decked with 5/8 decking material with a metal roof. If you need to replace the metal or shingles it's no big deal. If you need to replace the decking you'll need to respray the new decking. You will go in the attic and cut the foam around the edges of the decking that needs replacing.

[Stompy]

I have absolutely no attic vents at all, can't have them with a foamed house. My house is like a yeti cooler. The vents in the attic I was speaking of is ac vents, no outside vents at all.

[Stompy]

The attic ac vents, 2 of them on each side of the house, keeps the humidity out of the attic. When the heat or ac comes on inside the house it also blows in the attic.

[Corkpuller]

Thanks, sounds like I may need to have a sit down with y’all before I proceed.
Talk more later, I gotta settle down for the night

[tshooter]

We put in closed cell in our new home 6 years ago. Best decision we made. 2,400 sq ft, 10 ft ceilings, 1 2-ton unit and my bill has never been more than $125. I went 13 months where my highest bill was $65, most months were $23-$35 during that period.

All the extra storage in the igloo attic is awesome too. 6 years later and not 1 ounce of dust up there. Temps don’t exceed interior temp by 5-8 degrees probably.

[Corkpuller]

The attic ac vents, 2 of them on each side of the house, keeps the humidity out of the attic. When the heat or ac comes on inside the house it also blows in the attic.

tryin to figure this out, whole new ballgame to me, i'm ignernt to this method.

if you have hvac vents in the attic, i assume you'd have to have a return air up there as well, right.. ???

[Corkpuller]

We put in closed cell in our new home 6 years ago. Best decision we made. 2,400 sq ft, 10 ft ceilings, 1 2-ton unit and my bill has never been more than $125. I went 13 months where my highest bill was $65, most months were $23-$35 during that period.

All the extra storage in the igloo attic is awesome too. 6 years later and not 1 ounce of dust up there. Temps don’t exceed interior temp by 5-8 degrees probably.

Remember, we live in MUCH different climates than y'all do and that is one of my concerns.

[katyag]

I agree with everything John said. We have 3500' and our bill averages under $200 a month. We may have had one or two months in 3 years where it got as high as $250.

[Stompy]

tryin to figure this out, whole new ballgame to me, i'm ignernt to this method.

if you have hvac vents in the attic, i assume you'd have to have a return air up there as well, right.. ???

Yes, return air to the attic.

[krindgen]

Google, "building envelope." If the walls and roof are insulated (don't know why you'd do it this way) there is no need for the attic to be insulted. Your entire attic will be part of the insulated space. If you don't insulate the roof then the attic (ceiling joist bays) should be insulated and your soffit and ridge vented. I wonder if the idea behind insulating the roof is to keep the attic area at a somewhat lower temp than the outside to help with the mechanicals if they're put up in the attic.

[grout-scout]

After seeing what happens to foam and water leaks, I’m not a fan of it. Yes it’s a great insulation, but you better hire the right company to install it and an even better hvac company that understands it.

[Stompy]

I have foam, I've had a roof leak, it's no big deal. The savings is phenomenal, don't understand why everyone doesn't use it. In fact, most of the homes I've seen built around here for the past few years have used foam. All the hvac companies know about foam insulation, it's been around a while now.