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8 Answers

How are people prepping for wall penetrations?

I am hoping to start building an energy efficient house this year with an ACH50 below 1. To achieve this I am trying to have all the penetrations figured out before I start to build. My basic wall construction will be from the outside: LP smart products over 2X4 rain screen, 3" XPS, zip system sheathing(air barrier), 2X6 cavity with dense pack cellulose, and finally sheet rock. Since the zip-sheathing is the air barrier and the exterior surface is where the zip-tape seals to best I am trying to pre-plan all the penetrations before the exterior foam is applied.

In Mechanicals | Asked By Dillon Vautrin | Apr 3 16
8 Answers

Insulating old house from interior zone 4A


My project is located in D.C., climate zone 4A, mixed-humid.

We are renovating our old home for different reasons, including energy performance. My question is specific to the building envelop and improving the thermal performance as well as making sure our 'improvements' don't create a moisture problem inside the wall. Removing the siding seems cost prohibitive, plus the cedar shakes are still viable, so I'm looking at reducing thermal bridging as much as possible from the interior.

After doing a lot of reading, here and elsewhere I am considering the following assembly:

In Energy efficiency and durability | Asked By Adrienne Gallo | Apr 2 16
3 Answers

Wood floor installation

We are working on a house in Houston where the wood flooring installer is requiring the wood flooring to acclimatize in the house for 4-5 weeks with the permanent HVAC system installed and running in order to provide his warranty. The contractor usually installs temporary AC during construction so as not to clog the permanent system filters from the sanding, dust, etc and so when the owner moves in, the system is brand new as should be expected with a new house. The flooring sub is not accepting that. Has anyone come across scenario before?

In Mechanicals | Asked By Heather Gayle Holdridge | Apr 4 16
2 Answers

Replacing a wood deck with composite

When replacing a wooden deck with composite material there is usually a 1/2 inch discrepancy because the decking was 1 1/2 inches thick and the new composite is usually 1 inch thick. What migh tone use to handle this problem to enable the deck to end up at 1 1/2 inches thick again? Thanks

In GBA Pro help | Asked By Kenneth Riedel | Apr 4 16
21 Answers

Need help insulating an old non-vented cathedral ceiling

I am looking into the proper way to insulate a room in my home that has a cathedral ceiling. I am in zone 3 (southern California). The house was built in 1957 and the ceiling assembly is as shown in the uploaded photo. (drawing). the room is 12'x12' FYI.

From top(roof) to bottom... this is the assembly.

The roof is a metal 3 dimensional shingle (Metro shingle) so there is some venting "air flow" beneath the shingles. There is Titanium UDL50 synthetic underlayment, then 1x4 skip sheathing, 2x4 rafters, and then drywall.

In General questions | Asked By J Loc | Mar 1 16
3 Answers

Bungalow: second floor insulation

I have two questions.

1) In my knee walls are foil faced fiberglass batts with the foil face pointing into the unconditioned space. I want to place a layer of Foil-faced polyiso across the bats to stop thermal bridging, but then I got to thinking... am I creating a problem by having a vapor retarder next to a vapor barrier?

In Energy efficiency and durability | Asked By Kristopher Schuster | Apr 4 16
11 Answers

Slab/no slab in frost-protected foundation?

A frost protected shallow foundations is basically a tub of foam with a concrete slab in it. And very carefully laid out plumbing and utilities. I am wondering about leaving some of the slab out in places such as under a bathroom and simply framing that section in so the finished floor is level with the adjacent concrete floor (at doors) The framing would serve as a stop during the slab pour and prevent movement.

In Green building techniques | Asked By Robert Swinburne | Apr 2 16
0 Answers

No more importing euro fibreboard?

We've decided to shoot for PHIUS certification on a new build this summer. Our double 2x4 stud walls will be filled with >15" dense-pack cellulose. We're thinking of using SONOclimat's Eco4 fibreboard as sheathing. It's local (for us), it's recycled, 26 perms and R4 for 1.5" and, at 35$ for a 4'x8' sheet, affordable. Short of hitting up an engineer, I wonder if there is a simple way of determining whether it is robust enough for bracing or whether we need to add some metal strapping.
here are the technical specs.

In Green products and materials | Asked By william murray | Apr 4 16
6 Answers

Vegetated roof assemblies

I am quite familiar with vegetated roofs (aka green roofs). Some advantages include for membrane durability, reduced insulation, and perhaps some insulation. Other green qualities are habitat and owner connection with nature. I've been looking around GBA and can't find much discussio discussion about vegetated roofs. They seem like a good fit over many of the well insulated for systems discussed here.

In Energy efficiency and durability | Asked By Ethan T ; Climate Zone 5A ; ~6000HDD | Apr 3 16
25 Answers

Rigid insulation on the interior face of the wall

I am considering putting 2" of rigid insulation on the INSIDE of my perimeter wall in a home I am preparing to construct. This will serve as a vapor retarder and add r10 to the wall assembly that will include 5.5" of dense cellulose (r20 + r10 is not a bad wall). Here is the breakdown of the wall I am proposing: hardi Plank on 1x4 furring strips, Tyvek or similar air barrier, plywood sheathing, 2x6 framing at 16"oc, 2" rigid (xps) with taped joints, GWB.

In Energy efficiency and durability | Asked By sean stewart | Mar 26 16
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