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13 Answers

How to fix my unvented cathedral ceiling roof assembly?

We tried to build a house with a fairly tight envelope based on reading I could find. Well, apparently I messed up, so really want some advise before I mess things up more.
House is in central Missouri( zone 4, but real close to 5). Small, 750 sf but with an open loft making it about 940sf. Sealed Concrete slab as the finished floor, and new construction ( under roof in may but moved in The next January). Red metal roof and one side of that faces north..
Walls are 2x4 and we used open cell foam with 1/4" foam inside the studs as an air ( not vapor) barrier.

In General questions | Asked By Brenda K | Feb 16 17
6 Answers

Zip System R-Sheathing

Quick question about Zip System R-Sheathing.

The concept of a REMOTE wall, where exterior insulation is used to ensure that the structural sheathing stays warm (and thus dry), makes perfect sense to me.

The Zip System R-Sheathing is a compelling product because it saves several steps by installing all the necessary wall components in one go.

HOWEVER, from the pictures on their website, it looks like the Zip System R-Sheathing has the WRB on the outside, followed by the sheathing, followed by the insulation. So, doesn't this mean that the sheathing is cold?

How does that work?

In Green building techniques | Asked By Matt Culik | Feb 16 17
2 Answers

Rainscreen with gapped panels

Hello Again GBA'ers

We have a design for a ventilated rain screen ventilated with mixed cladding materials. This will be exterior to 6" of foam board insulation. One of the materials is Equitone, and the manufacturer recommendation calls for 3/8" gap between panels, they supply a butyl tape to face the furring strips, both to provide a dark color on the reveal and to provide a moisture barrier on the face of the wood furring strip. The panels are very long, and there will be long horizontal gaps.

Two questions:

In Green building techniques | Asked By Gerald Pehl | Feb 16 17
14 Answers

Noise from PEX/PVC drain pipes

We are at the stage of starting the framing for the new construction home in Pittsburgh. It is also a Passive House duplex. Our architect specified cast iron for domestic water drainage pipes (from shower and toilet, etc.), mostly on the account that these result in most quiet interior. For delivery of the water within the house, PEX is planned. Then we heard that iron pipes are more susceptible to clogging. Is some compromise, where pipes close to dining/living room are cast iron, and PEX elsewhere an OK option?

In General questions | Asked By Lucyna de Barbaro | Dec 6 14
5 Answers

I have a slab-on-grade floor (pre-1900) that sweats enough to where it can get slippery in summer

What can I do to prevent this?

The building is a raised "shotgun" in New Orleans. The lower area (about 7.5 ft. tall ) has been converted to an apartment. This is quite common here. Originally, these areas were used for storage only due to the possibility of flooding.

It is basically an unconditioned space, the hvac provided by window units.
The walls are insulated with Rolux batts, no ceiling insulation, and the old single pane double hung windows are fairly tight.
Is there an elastomeric, or epoxy type product that I can use to mitigate some of this problem?

In General questions | Asked By Roger Steinbrink | Feb 16 17
17 Answers

Radiant hydronic heating, embedded in slab, or over slab?

This is perhaps a very stupid question with an obvious answer, but..

Are there any numbers of how much more efficient is it to embed pipes for hydronic radiant heating in the slab, vs laying them ON the slab?

Also, as a rule of thumb, doing it in slab should be less expensive?

In Energy efficiency and durability | Asked By davor radman | Jan 27 17
20 Answers

Best cold climate exterior insulation assembly

Hello GBAers,

Long time reader, first time poster here. I have huge gratitude for this resource, and I've finally become a member.

We started on a PassiveHouse retro-fit journey quite a while ago, and we really need to finish- I'm gearing up to do that now.

Our architect spec'd 6" of polyiso on the exterior, fastened with 1x4 battens to which siding will be fastened, and which will also serve as a ventilated rain screen.

In Green building techniques | Asked By Gerald Pehl | Feb 9 17
5 Answers

Flash & batt insulation in Climate Zone 5

I would like to insulate a 2x6 wall cavity with a combination of either EPS or XPS and Roxul Mineral Wool - Can someone please let me know what thickness of FOAM would provide the best R-Value?

Mark Kozlowski
Nelson, BC

In Energy efficiency and durability | Asked By Mark Kozlowski | Feb 16 17
4 Answers

Open-cell spray foam wall insulation

Hi there,

I was doing consulting on a heating system in a new home this morning and brought up insulation as a subject of the heat loss calculation.
It was mentioned that they are going to be spraying open cell six inches thick in the wall bays. The house has 2 inches of styrofoam for the stucco on the outside. Next they have areas where there is a layer of tar paper or some wrap and then wood. Other areas the brick structure was retained.

In Green building techniques | Asked By Moe Hirsch | Feb 15 17
3 Answers

Super slim LED option

I have been looking at replacing my canned lights in the ceiling and considering two options. Unfortunately, cove lights, pendant lights or other options are not popular with my spouse.

In Energy efficiency and durability | Asked By Stan Weinstein | Feb 14 17
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