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5 Answers

REMOTE wall retrofit - the next steps have me puzzled

I live in Anchorage, Alaska (zone 7) in a early 70's split entry home. The original construction consists of 2 x 4 walls, but an addition to the house 2 years ago was built with 2 x 6 walls.

In Energy efficiency and durability | Asked By jon kunesh | Dec 7 11
40 Answers

Alternative (Non-Foam) Outsulation Strategy Using Rockwool

There’s a lot of talk about the benefits of exterior insulation, but also the downsides of rigid foam materials—that is, the chemicals involved, future disposal issues, wrong-side vapor barriers, susceptibility to fire and pests. It is possible to use rockwool / mineral wool as an alternative, but this is not often discussed or practiced, at least in this country. That may be largely due to the lack of compressive strength of rockwool compared to foam boards, requiring some strategy to support the cladding other than simply driving screws through the insulation.

In Green building techniques | Asked By Thomas Jefferson | Oct 24 10
17 Answers

disassembling the green roof Dagwood sandwich

Green roofs: raise your hand if you've done `em. I want to talk about absolute-minimal approach.

I'm about to get one set up on this outbuilding, and on reviewing the necessary layers, I'm wondering if I can strip the layers down to as few as possible.

Generally, the layers necessary are:
waterproofing layer
root barrier
insulation
drainage
growing medium
plants

Since we will probably be installing by putting trays of sedum in lightweight growing medium down, here's what I see:

In General questions | Asked By Minneapolis Disaster, 6B | Nov 16 11
3 Answers

Penetrations in deep exterior foam

In planning the construction of my house I may have some of those "obvious in hindsight" questions. When the exterior foam insulation begins to exceed the depth of a standard receptacle or lighting fixture box, how do you support them? Obviously you want to minimize the amount of insulation removed so providing solid blocking all the way back to the wall is out. I am picturing long screws through the back of the box and foam to solid blocking, with plastic spacing tubes around them to prevent crushing the foam due to fixture/receptacle movement.

In Green building techniques | Asked By Nathan Spriegel | Dec 9 11
21 Answers

Not sure if my vapour barrier is done right or in the right spot. Can you tell me what is right?

I live in Alberta, Canada (great white north). I built a new house myself and wanted extra insulation. I purchased 1" styrofoam that has foil on both side which passes as a vapour barrier (P2000 is the manufacturer).

In Energy efficiency and durability | Asked By Adam Willert | Jun 11 10
3 Answers

How extensive should rigid foam be placed under slab on grade frost wall foundations?

Schematic diagrams demonstrating the use of rigid foam insulation under slab on grade frost wall foundations always show the rigid foam under the slab and less frequently under the footer or on the external surface of the stem wall. If the goal is to have an optimal thermal break barrier under this type of foundation construction why not place the foam both under the slab and completely around both sides of the stem wall and under the footer? It seems to me that this is the only way to create a complete thermal break for the foundation.

In Green building techniques | Asked By Tim Ward | Dec 8 11
5 Answers

I have moisture under patio blocks laid over concrete. What can I do?

We bought a home that has a beautiful pool area with patio pavers all the way around. There is an area that retains moisture I couldn't understand. I looked at the original lot map, the house had a concrete patio that looks to be the same size of the moisture issue. I believe they laid the pavers over the concrete and that area retains moisture. is there anything that I can to correct this or prevent moisture?

In General questions | Asked By Paula Johnson | Dec 8 11
4 Answers

Wood shingles nailed through 1-1/2" Styrofoam

Climate zone 5, I'm building a high-performance home, on the exterior walls I used zip wall system with tape joints as my sheathing. I used 2-1/2" cap nails to install DOW 1-1/2" Styrofoam T&G with tape joints over the zip wall system. No furring strips over the Styrofoam. I'm placing home slicker as a drainage plane over the Styrofoam. Since I did not use furring strips I'm concerned about what type of siding to use. My thoughts are to use red cedar shingles nailed with 3" stainless steel hand nails seems to be the best approach.

In GBA Pro help | Asked By Peter Fusaro | Dec 8 11
10 Answers

Is thermal mass capacity impacted by the tiling process?

I'm wondering if you can lay tlle over a concrete subfloor without compromising the thermal mass capacity of the concrete.

Would an uncoupling system, using something like Ditra, have a negative impact? Should we be looking at using sand instead?

Our building site has great orientation for passive solar, but we'd prefer tile versus a finished concrete floor.

In Energy efficiency and durability | Asked By Christa Campbell | Dec 3 11
2 Answers

Valley Flashing Options?

Per my roof installer, the roofing shingle I have specified (Certainteed Presidential) cannot be woven in the valleys. He says it voids the warranty. He says we have to go with metal flashing (over the usual Ice and water barrier). Is there any other product I should be looking at besides the aluminum (.032) or copper (unknown gauge) he offers? Pitches are 6 1/2 and 8. The reason I specified this shingle was the "heavy texture" appearance so I assume any similar shingle will have the same restriction.

In General questions | Asked By Jim Orasky | Dec 8 11
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