new construction - insulation (East Texas)

[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 ***. there are custom home builders in lufkin that see it the same........

any y'all have first hand knowledge about it all

 

[RNeumann]

The style you speak of is something I’ve seen a few times in the south. I’m not a fan of spray foam but if that’s your flavor I get what they are going for. Basically all spaces are conditioned with the ceiling drywall/paint combo working to keep the attic and living area in two different temp ranges.

Check out buildingscience.com for a lot of good studies and ideas for your climate zone.

 

[jaxs]

It's my policy not to jump onto new technology,beit appliances,cars or health fads until it is proven. One comlaint I've heard is roof leaks are difficult to detect before major structrial damage is done. The debate continues but I'm not convinced cooling more space save's enough energy to make it a good idea. If you find a contractor with experience and track record,get a proposal for ground source heat pump. IMO,the best thing in Texas is a couple of big trees shading the roof. Foil faced decking has proven to save energy.

 

[RNeumann]

Here you go-

BA-1312: Application of Spray Foam Insulation Under Plywood and OSB Roof Sheathing | Building Science Corporation

It’s been around awhile- just not that popular.

 

[PEJ5]

I would think that insulation to save energy is as important in Texas as it is in Canada. Our building guidelines call for R60 attics and R32 walls. Insulating basements or under slabs is equally important in Canada.
Roof trusses are built with a raised heel allowing more insulation above the walls. Adding 2" of rigid insulation to the outside before installing the siding reduces thermal bridging - where cold travels through the wall studs.


Check out these guidelines
Keeping the Heat In | Natural Resources Canada

 

[3Ts]

I have a house built with spray foam done by a builder in Lufkin. In my opinion, the spray foam is - - well, there are pros & cons. 1st the con is that since you're heating & cooling the attic as well, I don't see much of a savings there. 2nd, the pro is that it seals the envelope and reduces air infiltration which is a big energy savings. I think the air infiltration offsets the attic, but not by much.

As for the problem that leaks won't show up until there is a real problem, I don't know. On one hand I'm inclined to agree, but on the other, the spray foam is a chemical that acts like a polyurethane glue and may tend to localize any leaks or damage. And because it's a glue it helps to reinforce the walls and roofs.

 

[Corkpuller]

I have a house built with spray foam done by a builder in Lufkin. In my opinion, the spray foam is - - well, there are pros & cons. 1st the con is that since you're heating & cooling the attic as well, I don't see much of a savings there. 2nd, the pro is that it seals the envelope and reduces air infiltration which is a big energy savings. I think the air infiltration offsets the attic, but not by much.

is that builder mike, with dream homes?

how old is your home?
you aren't seeing significant savings in yer light bill?

thanks

 

[EddieWalker]

My neighbor did this about ten years ago and he says that his electric bill has never been over $50. He also travels a lot and that might be part of that. He said his only issue is that he has to open a window to get his fireplace to burn good. It's too air tight for it to get a good fire going in winter.

 

[Corkpuller]

well Eddie, i suppose your neighbor would be about the closest to me considering climate. i just cant wrap my head around no attic ventilation in this HOT and HUMID climate.

 

[Lineman North Florida]

I know several people that have built several houses for themselves and both say there is no comparison, they claim their electric bills are less than $100.00 per month during the heat of the Florida summer which should be awful close to what you are dealing with, verses around $200.00 per month with a conventional framed home with R-13 in the walls and R-38 in the attic. It makes sense to me that if you don't allow the heat to transfer into you're attic it can't transfer into you're living area, and if you are worried about roof leaks just sheet it with tin screwed in the ridge and there won't be any, problem solved.