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9 Answers

Floor truss spacing and sub-floor options for a "stiff" floor : opinions?

I am currently building a slab on grade home, with 24" deep open web floor trusses (24" selected with the intent of having (2) 20x21" house long chases to run low velocity HVAC ducts, supply and return and avoid bulkheads).

My architect, who is admittedly old school/conservative, specified spacing at 16" OC, with 3/4" ply sub-floor. The house is 30' wide, and the joists are basically designed to take this full span. However, I have a mid width supporting wall/beam in the design, which basically cuts the span in half (max span from wall to exterior wall is 17').

Asked By Mai Tai | Aug 5 17
6 Answers

Peel-and-stick or Tyvek WRB?

Here is my proposed exterior wall assembly:

5/8 Drywall
Vapour barrier (for the building inspector)
2x4 studs at 12" o.c with 3.5" Rockwool batting
5/8" Densglass Drywall sheathing
2" Rockwool boards
cement board open cladding

I was commenting on other threads but thought I'd start a new one. I need the advice of the GBA members.

Question: Considering cost, performance and application, Should I use a SA membrane or Tape the seams of the sheathing and Staple on a WRB?

Self adhering membranes I've looked at:

Asked By Jamie B | Aug 11 17
12 Answers

Is this "double vapor barrier"..?

We are coming late to a new construction low income housing project and are trying to add a few energy efficiency measures. The house has Kraft paper faced R-30 insulation in the attic and no other surface for attic floor but drywall.

We are thinking of adding 6 mil poly sheets, taped at seems and edges and around electrical fixtures etc. before drywall install.

Asked By Lucyna de Barbaro | Aug 11 17
7 Answers

Tiny house with metal roof: vapor shield?

I’m building a 20’ tiny house on a trailer with a 3:12 shed vented roof vented. My current plan for the roofing and ceiling structure consisting of 2x6 rafters is as follows: metal roof->water and ice shield->5/8” plywood->XPS foam between rafters->tongue & groove beetle kill planks. I am located in zone 5b with cold snowy winters. Is this layering plan sufficient to prevent condensation issues in the winter? The question is, do I need a vapor retarder between the plywood and xps foam, or between the tongue and groove and the xps, or skip a separately distinct vapor retarder?

Asked By user-6887032 | Aug 10 17
13 Answers

How does someone cancel subscription when there seems to be no way out??

Could someone guide me in the cancellation of membership? it doesn't seem like it is possible to do so.

Thank you

Asked By James Someone | May 27 17
5 Answers

Venting: Roof ridge and gable ends without soffit venting

We are doing a vented roof with access to the attic space through the East Gable End.
The Roof Ridge will be vented.Instead of the soffits to provide air floor to roof ridge use the gable ends to provide air into attic space.

General info
20 feet x 35 feet length to gable ends. 700 square foot home
7/12 pitch simple gable roof
12 inch raised heel roof
Synthetic roof under lament
Low Heat coated Metal roof
The gable ends face east and west
Area in which we live in receives good south west wind most of the year.

So the question do I need soffit venting?


Asked By Richard Riso | Aug 9 17
2 Answers

Inadvertant trap in mini-split line set?

I'm finishing the installation of my mini split line sets and realized I may have introduce a "trap" into the line set due to the way I had to route it.

The main line set runs from the compressor to the branch box in the attic. From the branch box, the line sets run down into one stud bay, in a 180 degree bend, through a stud, and pointing back up into another stud bay. This 180 degree bend is my concern.

Asked By Mike M | Jul 28 17
3 Answers

How do I prepare for a blower door test in new construction?

I'm interested in doing a blower door test on my new construction house.

I have read some of the articles on here about blower door testing, and most appear to focus on existing construction.

One article said to preform the test on new construction after insulation, but before drywall.

In the typical insulation / drywall progression, wouldn't the walls be insulated, then everything drywalled (including the ceiling), and then ceiling insulation laid on top of the ceiling drywall?

Asked By Adam Peterson | Aug 10 17
5 Answers

Can I put rigid foam insulation over plaster exterior walls of a brick house?

I live in central Illinois and it gets very hot or cold during summer and winters here. My bungalow was built before 1900 so there's literally no insulation in the house except for the attic. I was thinking of putting up some the pink R-10 rigid foam board insulation on my walls and then drywall over them. the walls currently have layer of lath, then plaster, then thin wooden paneling over the plaster. Is it ok to attach the foam boards over the wall without tearing anything down? I don't mind extending the windows and doors or refitting the electrical outlets. Thanks.

Asked By Darkpie | Aug 10 17
10 Answers

Plumbing question: Drainage vent for tiny house not hooked up to septic

I’m at the plumbing stage for my tiny house on wheels. After hiring a plumber, I see that he has an aav vent for both the kitchen sink and bathroom sink, in between the wall studs.

1) Considering that I am not hooking up to sewage (composting toilet), do I even need a vent?

Asked By Grey Wolf | Aug 5 17
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