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James11470301 09-09-2012 06:07 PM

How do insulate existing house following Hurricane Isaac
I have a couple of questions I hope can get answered here. Ive searched all day and not really found any answers.

I live in south Louisiana, very hot and very very humid. After this last hurricane I am going to be tasked with residing my house. No big deal, it needed it anyways.

The house is about 25 years old or so. It currently has sheetrock walls inside followed by regular insulation batts, plywood sheathing, black tar paper wrap, and finally vinyl siding.

I wanted to wrap the house in double bubble foil barriere was told by the company that it is not recommended because the reflected heat will damage my new vinyl.

What is recommended in a situation like this? Not interested in spray foam or the loose insulation. I was reading on the rigid foam boards but saw an article where it is mot recommended because of the batt insulation.

My question: if I go with foam boards and seal the tightly do they go on top of the black paper or should the black paper be removed? Should I rewrap the house with te perforated Tyvek and then foam board? What should I do and whay order does it need to be in? Im really concerned about moisture due to the humidity down here.

My house has all vented vinyl soffit all the way around, gable roof with ridge vent at the top. It sits on a slab about 4-6 from the ground.

nealtw 09-10-2012 12:17 AM

Hay welcome. As foam would be a vapour bearier I don't think it would matter what other wraps are there or missing, as wraps are intended to let moisture out.

James11470301 09-10-2012 02:45 PM

So I can just install the rigid foam board over the black wrap and install my vinyl? I havent looked much at the foam board, but from what I have seen I have noticed some boards come with a wrap or foil on one side. Should I use plain foam or get one with the foil or other material? Which way would the foil or material side face, towards the house or towards the vinyl?

nealtw 09-10-2012 04:56 PM

We need someone with more knowledge about practice down there.

James11470301 09-13-2012 07:23 PM

Seeing that the thread got little response, anyone recommend any other home repair forums?

GBR 09-18-2012 08:30 PM

Neal is correct, you want/need a vapor barrier (foil-faced foam board) on the plywood. Pull the black paper to get a quality caulking seal at foam perimeter, pp. 11, Fig. 6;
You don't want humid air getting to your cavity insulation. No interior v.b. like mirrors, paper-faced batts, etc. Thickness of f.b. to prevent cavity condensation;
Zone 2= R-4+; Tape seal the joints, add a WRB if you want, check with local AHJ.


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