Hi all,

Im located near galveston, texas. We lost our house due to hurricane ike and are starting to discuss our rebuild. We are going to build a 1700sf house on stilts 17ft above the slab. Downstairs will be garage space etc.

In planning the insulation of the house, the contractor is telling me to just go with blown cellulose type insulation. He says is pretty energy efficient etc.. I understand it may be, but i would like to go further. Below is what i was thinking.. can yall tell me what your thoughts are on it.

Roof with radiant barrier underside of the sheathing.
Spray foam insulation on inside roof decking ( 1
" 1/2 # foam to seal)
Cellulose insulation in walls and blown inside attic
Spray foam in garage ceiling ( main floor sealing)

How does this sound.. In this type of situatiion, do i need to vent the attic? Should i get some sort of air mover for the house etc.

Thanks

Thomas

I would recommend foam in the frooof deck--don't know if the radiant stuff (you mean the shiny stuff) would do much with the foam. Foam is a much tighter fit. We just put it in in our roof deck. You could foam it before y our walls are closed Personally I would avoid cellulose. We were advised by the engineer against sealing or insulating the attic floor, in addition to sealing the roof deck with foam--you need air circulation.

Use foam for the garage.

WE used a product called Demilic open cell--There are several types of application.

What type of HVAC system are you putting in. We just put in a Geothermal DX system Earthlinked formally called ECR but not co. in Pa) in our 100 yr old home, If you are considering a geothermal system I can provide additional info on what we have. WE also have upgraded our thermostat so that it will help with the humidity--Honeywell 8000 I think.

Originally from NO Gald to se you are rebuilding.

Please let me know if I can help
alice

Sorry to come back so soon

If you have not started building yet, have you considered SIPs

Texxan1

Sorry to hear that you lost your house to hurricane Ike and hopefully that will never happen again. That being said, if I lost my house to a hurricane, I would certain consider building the next one with Insulated Concrete Forms (ICFs). They have a forum on this website that you can review and make your own opinion of the best way to build. They aren't much more than traditional stick built and very energy efficient. I believe in Texas your homeowner's insurance can also be reduced significantly if you build with ICFs. I would at least investigate the product.

Best of luck - renangle

You can't really use ICF's with stilts very well. If you are already going to have a spray foam contractor on site, just have him go ahead and spray all the walls and ceiling with foam. It will also add to the structural integrity of the walls and ceiling.

Closed cell polyurethane spray foam will add strength to the structure.  I do not believe that open cell will add any strength.

You can do ICFs on stilts, then at least it won't blow/float away again. ICFs are the only way to go.

For attics spray urethane and blow in on top of that, is economical. I prefer fiberglass.