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6 Answers

How should I insulate my exterior walls?

I live in zone 4a, northern Virginia. My house is a single story, 2x4 exterior walls, no plastic wrap on the interior, no sheathing on the exterior, no house wrap on the exterior, and the exterior siding is RB&B board. The house is 40 years old and has just 40 year old batting insulation with siding. I want to spray foam, from the exterior, but one person says do not use closed cell because it is too hard to cut smoothly and water could settle in any uneven places, the next person says to only use closed cell.

In Energy efficiency and durability | Asked By Michael | Nov 23 15
9 Answers

Why will our heat pump not warm the whole building?

Our office has complaints about the building we work in -- it will not get warm. We have an old boiler, but when we renovated in the 90's the company installed heat pumps and connected the two systems together.

Once it hits 32 degrees, the boiler was supposed to come on. Instead, half the building is cold and the other is hot.

Can anyone please explain what is going on here, and can it be fixed?

In General questions | Asked By Desirae | Nov 23 15
7 Answers

Window advice - Zone 3

Well we are looking at Marvin all Ultrex, Andersen 200, Softlight Elements and Sunrise Vanguard.

We are in Zone 3 on a heavily wooded lot, 4 small window on the west, 2 covered by porch, 15 on the north northwest, 4 on the south and 2 sliding doors, one 6 footer on the south with a 8 ft covered porch and a 12 ft sliding door on the east covered by a 12ft deep screened porch.

What should we look for in U-factor and SHGC?

In Energy efficiency and durability | Asked By Quinton Bryant | Nov 10 15
1 Answer

Can you install a metal panel roof on plastic furring strips?

I am getting ready to install a metal roof (36" wide panels) onto my SIP roof. I've read that a 'cold roof system' is the way to go with SIPS - to allow any moisture that comes through the sips to evacuate. Is the extra layer of sheathing over the furring necessary, wouldn't you get more ventilation if the roof was installed just on furring strips? And could these stand alone furring strips be the plastic Cor-a-vent Sturdi-strip product to allow for better drainage and ventilation? Does this product make for a weaker connection of the metal panel to the sheathing?

In General questions | Asked By Rene Cappuccino | Nov 24 15
3 Answers

Installing rigid foam insulating board on the interior of an exterior wall

1890 house we've pulled the plaster and lathes off. Have access to exposed exterior wall between studs from the inside. Can we cut and tightly fit 2" board between the studs, Should it be snug to the exterior wall? Or will there be a moisture issue...how do we prevent moisture issues? If we double layer the board does it increase effintiency? do we need to tape the seams against the studs? We live in Maine.

In GBA Pro help | Asked By Andrea | Nov 23 15
8 Answers

ERV or HRV that scrubs the incoming air?

Hello all, I'm planning a new home and need some help on a ventilation issue. A couple of my neighbors burn a lot of wood in the winter, so much that you smell like a BBQ pit after a few minutes outdoors sometimes. Is there any ventilation system on the market that would scrub incoming air--activated carbon maybe? Or can anyone think of way to alter ventilation ducts on a typical ERV or HRV to do so that is safe for the systems and for me?

In Mechanicals | Asked By Antonio Oliver | Oct 9 14
14 Answers

HVAC Retrofit for 1918 Colonial Revival in CT

My husband and I own a 1918 Colonial Revival in CT... where summers are hot and humid and winters are cold. We bought the house 4 years ago. But we're not spring chickens... we're in our 50s so we won't see as much return on investments as say... a younger couple might. (We have no children but my husband's elderly uncle might stay with us in Feb. 2016 so we need efficient heat for him.) We also don't have a big budget - plus our house is in a neighborhood where the houses are losing value, so we don't want to spend a tremendous amount on renovations.

In Green products and materials | Asked By Margaret Tehan | Nov 22 15
0 Answers

Does EPS shrink with time?

On the following link a comment was made that I have concerns :
"On the foam, two layers is better than one, with seams taped on both layers, and overlapped by a foot. Over then next 40 years the EPS is going to shrink a bit, but the performance hit won't be too bad if the seams are overlapped and still reasonably air-tight."
Answered by Dana Dorsett

In Energy efficiency and durability | Asked By Edwin Perdomo | Nov 23 15
3 Answers

Radiant floor in very thick slab

I'm working on a project (climate zone 4C) that will use a thick (~16") raft slab due to poor soil conditions and the client is interested in a radiant system as well.

If the pex tubing were held approximately 2-3" below the top of the slab and the entire perimeter and sub-slab were insulated to R-20 would it make sense to use a radiant system?

I imagine at the very least it would be a huge flywheel that a very long time to heat up or cool down, so you'd have to just set the temperature and leave it alone.

Any thoughts?


In Energy efficiency and durability | Asked By Daniel Stewart | Nov 23 15
4 Answers

Vapor barior on SIPs in a hot humid climate

We have been asked to repair siding on a sips panel house in a hot humid climate. Our client has been advised to have us put a vapor barrier over the panels before installing the siding. This will essentially put the OSB between two vapor barriers... in a hot humid climate. This does not seem like a good idea. What do you think?

In Green building techniques | Asked By Hugh Stearns | Nov 20 15
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