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11 Answers

Polyiso foam in basement: a rim joist question

Hi all,
Love this site, great hints
Now Im in Rockland county a little north of NYC and have a 2007 2 story colonial
I have added to the R38 with another 8" of cellulose and now am looking at the basement.
It is unfinished but I has r19 batts in the ceiling (unfinished)
So I was looking at putting 2" Poly Iso board glued to the basement walls, the ceiling height is 8ft so perfect fit for the boards

In Energy efficiency and durability | Asked By Darren Finch | Feb 11 14
3 Answers

Cut and cobble vented cathedral ceiling

We are finishing our attic on a tight budget. We just had new roofing installed 2 years ago and unfortunately did not add continuous exterior insulation at that time since we had an insulated attic (at the time). The floor-to-ceiling height is so low that every inch counts, so we are looking at cut and cobble to maximize R-value within a very small space. House is 1927 drafty everywhere, so unvented roof seems impossible to retrofit appropriately without spending a lot of time and money. We are in Portland, Oregon (moderate climate).

In Energy efficiency and durability | Asked By Miyeko Endy | Jun 18 14
1 Answer

How best to insulate the outside of the sheathing?

What say you wall system experts about this "new" product vs. my old favorite Thermax?


In Green products and materials | Asked By Morgan Audetat | Jun 18 14
1 Answer

I have an old wood window sill that I want to install PVC Trim over

After I scrape out, fill any rotted areas with a spackle or epoxy mix and sand what other prep do I need to do before attaching my pvc trim, caulking & repainting?

Because of the design of the frame there are infact 2 small sills where the storm windows used to be. When the windows were installed PVC trim was put around all sides of the storm window area with a quarter round base (to cover the sloped sill gap). The paint on the large sill has taken a beating, so I want to extend pvc trim over it.

In GBA Pro help | Asked By Mike Tew | Jun 18 14
9 Answers

Insulating PWF basement

The "new plan" is to insulate the outer wall of my PWF basement with strips of EPS between the studs since I've found the material at a cost lower than mineral wool bats.. I'll cut strips of the sheet goods and install them much like bats for a total of 7 1/2"thickness. Inside the foam will be 3 1/2" of mineral wool as an ignition barrier for a cavity r of 45. Since my outer insulation is not air permeable, I should not need an interior vapor/air barrier.

In Energy efficiency and durability | Asked By Jerry Liebler | Jun 17 14
1 Answer

Hot water distribution

I have an electric water heater that I’d like to move from one end of my house to the other and I'm wondering how to calculate any potential energy savings.

All of the water users including the kitchen, laundry, and bathroom are tightly clustered at the front of the house where our town water supply enters the foundation. But the hot water tank is at the opposite end of the house about 30’ away, for reasons that predate me owning it.

In General questions | Asked By Mark Fredericks | Jun 18 14
3 Answers

Best source for domestic hot water?

Getting ready to build a LEED certified home, tight construction, excellent quality windows. Ground Source Heat Pump based HVAC. Will use excess heat from heat pump for hot water, but need a storage/booster tank. HVAC contractor wants to use standard resistance tank heater. Is this sufficient? How do I best find a highly insulated tank? Essentially no one in my area of the country (Northeast Indiana) is building like this. Heat Pump tank?

In Mechanicals | Asked By Andrew Katz | May 9 14
7 Answers

Will a single ductless mini-split heat pump be able to distribute its air evenly throughout my house?

I am in the middle of a deep energy retrofit of my 1,200 sf New Mexico house, and a manual J calculation of the projected loads once my projects are completed shows an estimated heating and cooling load of only around 13,000 BTUs each, compared to the current baseline of 41,000 heating / 28,000 BTUs cooling.

Since this is such a small number, my existing 125,000 BTU furnace will become even more ludicrously oversized than it is now. So on everything is done, I'd like to replace it with a single ductless mini-split heat pump.

In Mechanicals | Asked By Nathaniel G | Jun 13 14
1 Answer

Window shading in a cool climate - is it needed?

I'm designing a small up/down duplex in a mountain climate with cold winters and cool summers. Do I really need or want window shading overhangs with a relatively high south glazing ratio (13%)?

In Energy efficiency and durability | Asked By Lars SG | Jun 17 14
16 Answers

Rubberized spray to seal rigid foam seams?


In General questions | Asked By Evan Gentler | Apr 13 14
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