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5 Answers

How to tie in existing shingled roof when adding exterior foam?

I am adding 4" of rigid foam to my house and am looking for suggestions on how to flash where the adjacent wall ties into existing roof shingles. I am curious if there is a way to put the foam on top of the shingles and then flash. This would, of course, cover the existing step flashing and I am not sure if it is a good idea. My original thought was to remove the shingles close the wall and butt the foam straight to the roof underlayment and redo the connection on the outside of the foam with proper tape, peel and stick, and step flashing. Is there a better way?

In GBA Pro help | Asked By Brian Otten | May 14 15
2 Answers

Basement perimeter wall construction

My basement has a full perimeter sump pump; drainage mat on wall from 1 foot below ground level to loop into the plastic cove that empties to the sump drain below; limestone foundation walls; penetrating sealer on the concrete floor.

I plan on installing light steel perimeter walls where no steel will touch the limestone foundation walls. Closed cell spray foam, treated with a fire barrier, will be installed professionally after plumbing and electrical runs are completed.

In Building Code Questions | Asked By Donna Agah | May 15 15
24 Answers

Exposed Wigluv tape

The spec sheet for Siga Wigluv tape claims that it is "UV stable". Does
this imply that it's appropriate for little seal-up jobs on the exterior?
There are a couple of funky end-cap joints on my metal roof which could
let water in if windblown rain arrives horizontally, and I'm thinking
a slap of Wigluv over the slots would be an acceptable fix if it's
likely to last more than a couple of years under sun exposure.

Or are any of these products too new to really know? Did any of the
Siga offerings make it into the "backyard tape test"?


In Green products and materials | Asked By Hobbit | May 9 15
3 Answers

Poor man's spray foam help

Newbie here:

I am rehabbing a stickbuilt cottage in FL. It was torn back to studs by the previous owner. I obtained permits and am actively getting through the inspections and such. Next step is insulation. I discussed the process of foaming in cut foamboards and the county seemed ok with it. I bought 1 1/2 inch polyiso board from a recycle group that is in great shape. I have close to 200 4' x 8' boards.

In GBA Pro help | Asked By Ferrell Brown | May 14 15
9 Answers

Window replacement

Hi. I need to replace a 5 1/2 foot x 22 inch window in my kitchen . It is 16 years old, has had foggy streaks in it for over 5 years (gets lots of sunlight) and I am told it can't be repaired.
I called two companies to ask for quotes. They replied with quotes over the phone. There was a price difference of over $100.
Turns out one quoted 3 mm thick glass, one quoted 4 mm. thick glass.
Don't they need to know the thickness of my current glass, and match that?

Is there anything else I should specify in the quote? If so, in your view, is it a 'nice to have' or a 'must have'?

In General questions | Asked By Ann Piece | May 14 15
2 Answers

Foamboard and creep deformation

I have been trying to find a way to insulate a brick ledge on the north side of my home. I am planning a large insulation upgrade to help get my floor heat somewhat working and seal up the house some.

In General questions | Asked By Mike M | May 11 15
3 Answers

Insulating rafter bays with sistered roof rafters

I have a newly constructed home in Massachusetts, built to minimum energy standards (or maybe a little below).

The attic is unfinished, but the builder planned to finish it one day so he insulated the 2x10 rafters with a "flash & batt" approach. There are 4 inches of a sprayed on foam in the rafter bays (I would guess R-24 to R-28) and 3.5 inches of R-15 fiberglass. The fiberglass is held in place with vinyl straps and a layer of Membrain vapor barrier. There are soffit vents and a ridge vent, but these appear to be unused and blocked by the foam, at least in the rafter bays.

In Energy efficiency and durability | Asked By David Lewinnek | May 14 15
1 Answer

Wall system for recording studio / home. Vapor questions?

Hello, thanks in advance for your time and knowledge. This site is a great resource.

I am building a home / recording studio in Murfreesboro, TN (zone 4A) and have some questions about my wall system. My plan is to build my walls in the studio as such: vinyl lap siding, 1" xps foam taped at all seams, osb taped at seams, 2x4 walls with rock wool batts, 5/8 drywall, 1/2" sound stop fiberboard and finally one more layer of 5/8 drywall painted. All air sealed as best I can. My question / concern is about vapor.

Does this wall system pose any issues with vapor?

In General questions | Asked By JOE ROBERTS | May 13 15
6 Answers

Flat roof advice needed

I’m building a carport and breezeway in southeastern Michigan and I’m struggling with construction methodology and products for the proposed flat roof.

Flat roof? I know…Martin's Ten Rules…But… I would like to use all this roof real estate. This roof will cover a substantial portion of my small urban lot and I think, in the future, this could be valuable space. A Small Deck, a Modular Green Roof, Potted Gardens, Solar Panels…

In General questions | Asked By Howard Road | May 11 15
3 Answers

Spraying foam into stud bays without any kind of barrier

One of my clients has a pre-war home, (Civil War, that is), and would like to spray foam into the stud bays, although there is no barrier of any kind. Just old pine siding nailed to the studs.
I told him first that he should re-naill the siding using splitless ring shank nails to secure the siding.
Without any kind of barrier, I envision foam squirting out between the gaps.
Short of removing all the siding, and installing a vapor barrier, I suggested lining the stud bays from the inside using roofing felt stapled to the studs encapsulating the stud bays.
Any better ideas?

In General questions | Asked By roger steinbrink | May 13 15
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