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31 Answers

Double wall with cellulose and zip sheathing in the NW?

I'm slowly getting rid to build a house in Seattle (zone 4c) and have a wall system I think would work well, but wanted feedback:

Cladding (hardi-panel) on furring (rainscreen) on building-wrap (tyvek or similar) on zip sheathing (taped) over a 12" thick 2x4 double wall (staggered?) filled with dense-pack cellulose with drywall finish.

I know the zip system is a WRB but I would be using it mostly as an air-barrier and preferring the mechanical joint of lapped building wrap to a chemical joint of the zip tape (although that would be a backup).

In Green building techniques | Asked By Daniel Stewart | May 29 12
2 Answers

Best insulation method for new construction, 3-ply flat roof in Central Florida?

We are building a new home in Central Florida - hot and humid weather. Home is 2 story, CBU on 1st floor and 2 x 6 frame on second story. We have a very low pitch, commercial grade flat roof with 2 ft overhangs. There is only about 2 ft space in the trusses and much of that is filled with A/C ductwork. The builder had planned on R-39 blown-in, but now realizes this will be very difficult to get in the space properly, and then vented soffits are going to allow wind drift of the insulation. After reading here, we've decided on non-vented soffits since we have a flat roof.

In Energy efficiency and durability | Asked By Kimberly Naoumoff | Jul 6 12
1 Answer

How do you apply exterior siding over metal building siding.

We have a metal home and would like to add a more appealing siding over the metal sheets. Any suggestions on how to do this?

In General questions | Asked By Casey Wall | Jul 6 12
2 Answers

How should I frame and insulate?

I am building a 2300 square foot, 1&1/2 Story, home for my family on the seacoast of New Hampshire. The building's foundation is going to be a slab on a frost wall with radiant heat. The footings were just poured and I am about to order material for the frame. I want to build a simple fairly energy efficient building.

In Energy efficiency and durability | Asked By John McCormack | Jul 5 12
2 Answers

Any issues with using rigid foam board as in fill in exterior walls.

200+ year old colonial I am residing from the exterior. Removing everything so I am looking at the back of the horse hair plaster. Could dense pak cellulose or have open or closed cell foam sprayed in from the exterior. The problem is timing. I will be working on this a couple days at a time stripping and sheathing. I have three sides to do and I don't want to coordinate with an installer four or five times to come out when I am ready. So my thought was to use rigid foam (its post and beam) cut roughly to size and spray foam around the edges to seal it in place. Then fill the bay this way.

In General questions | Asked By terry grube | Jul 5 12
3 Answers

Attic insulation

I have 20 year old home in SC that has fiberglass batts between ceiling joists and a few years ago I had blown fiber (12 inches) on top of that. However the area over the attached garage has never been insulated at all. Since we are having record heat I've decided to insulate the garage area since yesterday it was over 100 degrees in the garage. I am not sure that I am getting full benefit out of the
existing insulation due to pot lites and perhaps the soffit vents may be blocked or partially blocked.

In Energy efficiency and durability | Asked By Jerrry Harris | Jul 3 12
6 Answers

Double stud walls & wood shrinkage

My evolving plan for my new house in northern Michigan uses double stud walls. The outer wall sits on the concrete basement walls while the inner wall sits on the floor that sits on an inner stud wall in the basement. The inner stud wall of the basement is separated from the concrete by 3" of XPS. The outer stud wall supports the roof trusses. The inner main floor stud wall is sheathed on it's exterior side and this sheathing is the vertical portion of the primary air barrier. The outer stud wall supports the roof trusses.

In Energy efficiency and durability | Asked By Jerry Liebler | Jul 3 12
1 Answer

Insulating floor of addition

We are adding a 2nd story addition to the back of our house in Portland, Oregon. The addition is supported on columns so the first story is open creating a covered porch. I am trying to decide how to insulate the floor since it is open to below and will have plumbing in the floor.

My thought was to use R-30 unfaced fiberglass batts in the floor, a layer of 2" XPS fastened to the bottom of the floor joists, 2x4 flat sleepers, and then 1x6 T&G.

In Building Code Questions | Asked By David Fischer | Jul 4 12
11 Answers

Most energy-efficient ERV?

I'm planning a net-zero energy home built from SIPs, and am trying to size my PV system accordingly. Unfortunately, I'm finding that the ERV that the home needs eats electrons with relish (one model, if run at the highest setting, will consume about 6 kWh per day if it runs continuously). That said, I don't understand the workings of an ERV to know if it does run continuously or cycles, or what the average daily electricity consumption is. I'm hoping folks on this forum can share their insights.

In Mechanicals | Asked By Claire Anderson | Sep 16 09
9 Answers

Condensation Problem

I decided to liven up this gloomy winter day in the Mid-South, by posting about a problem I recently encountered. I am just posting the information pertaining to the problem and will not add my two cents about the possible solution until we see what others think about this. Pictures are attached.


In General questions | Asked By Grant Dorris | Jan 13 11
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