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7 Answers

Best backfill material for frost protected shallow foundation?

We have a frost protected shallow foundation (monolithic slab) at our house in NH (zone 6), there is 4" of XPS for the slab edge (protected by the aluminum flashing) and wing insulation. The white material is cellular PVC board and then spruce clapboards.

When we finished the insulation, we covered it in some leftover screened sand to protect it before we were ready for landscaping. I've attached a photo showing some sand scraped away, there's anywhere from 2-6" currently on the wing insulation depending on location.

Asked By Brian P | May 26 15
2 Answers

Add exterior foam -- but paper-faced batts?

I am about to replace the windows on one side of my house, which for various reasons will require removing my existing siding. I also have in my possession a whole bunch of 3 inch foil faced polyiso foam board, the perfect opportunity to add an R19 layer of foam on top of my existing 2 x 6 walls with fiberglass batts. Problem is, I'm sure the batts have kraft facers on the interior. So I'd be creating a vapor barrior sandwich.

So what are my options? Here are 5 that come to mind,

1 - I could of course do nothing, which dramatically simplifies things.

Asked By Kyle Hollasch | May 26 15
9 Answers

Building wrap as an air barrier above a cathedral ceiling?

Hello,
I'm building a small house in Alaska with a 12/12 cathedral ceiling. I'm planning on a 1 1/2" vent channel above the fiberglass batts I will be using. Venting will be the usual eave to ridge vent design.
I've been advised to create an air barrier above the batts so they aren't wind washed by air traveling up the vent channel.
I haven't been able to find much information on this approach, and none of the builders in my area are familiar with it. Can anyone supply me with some "do's and don't's" one this technique?

Asked By Justin Smith | Apr 2 15
3 Answers

Insulating an old home

working on an old house, removed lathe down to the studs and the outside clapboard siding. There was no sheathing so what is exposed is the horizontal clap board siding. What is your recommendation for insulating the outside walls. Is it possible to use foam insulation (closed cell or open cell foam) directly against the siding or do I need some kind of air space between? If an air space, would15# black felt paper against siding be sufficient? the back side of the siding has never been painted. Siding is pine and 140 years old. Would appreciate any input.

Asked By John Conway | Feb 24 15
5 Answers

Is there an energy efficiency penalty for an oversized dehumidifier?

If i buy one that is oversized for my basement it will presumably run fewer hours a day at higher wattage, is there any penalty or lower effectiveness on this?
The one i am considering is 1.85L/kWh energy star rated compared to another 1.85L/kWh unit.

Asked By Alan B | May 22 15
2 Answers

Perlite in wall cavity recommendations.

I have a 2x4 wall cavity that is only about 5" wide. The cavity contains a steam pipe which is uninsulated. The cavity is obscured by another wall that makes access to it very difficult.

I would like to fill the cavity with perlite to insulate the steam pipe. I can close up the wall to prevent the perlite from leaking out, and have access to the top.

The house was built in 1928. From the outside: brick, air gap, roofing felt, 3/4" tongue and groove.

Asked By Kurt Kiley | May 25 15
6 Answers

Slow rise foam or dense pack cellulose in roof slope?

Cape Cod style house– i.e., under roof is kneewall, slope, and small collar attic above the flat bedroom ceilings

1925 house in Washington DC area with slate roof on front side of house, asphalt shingles in back. Roof deck is boards, not plywood or OSB. Currently there is a small amount of cellulose on “attic” floor and some poorly installed fiberglass batts on some areas of roof deck in kneewalls.

Asked By elizabeth hilder | May 17 15
4 Answers

What type of rigid foam is best for under siding?

We are removing the existing siding down to the diagonal board sheathing. We are making some necessary repairs at this area where windows have leaked, then covering with Grace Vyncor env-s self-adhering housewrap. This seamed to be a good choice to seal all the gaps between the boards. All penetrations are flashed to this level. Then we plan to install 1" foam panels with seams taped, 7/16" Zip panel strips for a rainscreen, then LP Smartside lap siding. We plan to use foil faced poly iso board. Is this a good choice?

Asked By mike labesky | May 26 15
4 Answers

Prepping a basement foundation for finished basement down the road

We are looking to finish the basement of our 100yr old house in a few years. I know there are some potential moisture issues with the rubble foundation. We usually experience some flaking during the spring thaw. My thoughts on repairing the foundation is to have the interior and exterior reparged / repaired before we even consider any waterproofing.

One that is done, should we give it a year before we invest in waterproofing or can we do that after its hardened (after 28 days)?

Asked By Mike Tew | May 26 15
18 Answers

Is there a standard factor General Contractors use when calculating their fee to construct

I am in discussion with a builder to construct my new home in zone 4B. We have engaged the services of an energy modeler to determine how to build the most efficient house within the budget. We are grossly over budget, at the moment. I noted that the GC has build a 16% fee into the budget to build the house. This is on top of all the subs and the contigency. Not wanting to negotiate something I have no background on, I'm wondering if this is a negotiated fee or is there some standard? I understand my builder needs to make a profit but I would love to get 16% return on my investments!

Asked By scott schroeder | May 22 15
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