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6 Answers

Mini-split energy usage

My first winter with a Mitsubishi ductless 15000 BTU (MSZ-GE15NA & MUZ-GE15NA). It's been in the low 30s in Seattle the past few days. I attached the electric usage recorded by my e-gauge. In the past (warmer temps) the usage curve is pretty flat. Now it's pretty jagged. Is it working properly (i.e.efficiently)? Thanks.

In Mechanicals | Asked By S K | Dec 5 16
2 Answers

Insulating 4-inch exterior walls

I am in the process of total gut remodel project, zone 5, 2x4 walls and installing vinyl siding.
I am trying to decide if I should use structural insulated sheathing such as Huber Zip-R and closed cell foam to fill stud cavity's. or install foam on outside exterior sheathing and use open cell foam.
any feedback would be appreciated.

In Green building techniques | Asked By Steve Karkau | Dec 5 16
1 Answer

Filling nail holes in Zip?

I have a question. Framing almost done. Have exterior sheathing done with Zip board.

I noticed that the framers' guns' pressure was high, and nails in some areas went deep into Zip, or in some areas nails missed the studs.

Question: Does it make sense to try to fill deep shot nails with a liquid barrier of some type?

If yes, what type?

I was also thinking of putting a stapled or peel-and-stick weather barrier over the Zip instead. Does that make any sense?

In General questions | Asked By Boris Rubinstein | Dec 5 16
3 Answers

Fill stud cavity with fiberglass insulation?

I am finalizing a house design in zone 5. Exterior walls to be insulated with R10 XPS exterior of the sheathing and R13 fiberglass in the wood stud cavity. Peel and stick will be directly applied to sheathing per REMOTE style walls.

My concern: wood studs will be both 2x4 and 2x6 construction, with 2x6s where walls are tall (10 ft.). Is R13 insulation pushed towards exterior (I'll have to figure out the best way to do that) OK or should I fill the cavity with insulation in the tall walls? Will ratio of R19 to R10 work re: moisture control?

Thanks in advance.

In Green building techniques | Asked By Joel Cheely | Dec 4 16
3 Answers

How would you air seal existing sheet rock to the bottom plate?

Building a new house in Syracuse NY. Sheetrock is up but no trim, mud or paint yet. I have been doing a variety of things to air seal and am looking for advice on how to seal the sheetrock to the bottom plate. The bottom plate is already sealed to the subfloor. Foam, caulk or tape? I have used foam in a previous house but I am not sure that it worked very well. I am leaning towards tape. Any suggestions?

In Energy efficiency and durability | Asked By david schreiber | Dec 3 16
7 Answers

Ipe wood vs. Azek (PVC) decking

My cedar deck has rotted. Periodic sanding & staining extended its life but now it is over. I am considering using either ipe wood or a PVC decking material (brand Azek). From the little I know, trying to consider a life-cycle assessment, neither seems like a great environmental alternative. Is there a clear choice between the 2?

In General questions | Asked By Betsy Leibson | Apr 11 16
8 Answers

Boards covering the top plate to air seal in attic - Top plate is not accessible

Many of my top plates are completely covered by other boards. I.e. Some of the top plates have 2 2x4 boards butted together on top of it (Effectively making a 2x8 with a split in the middle.) While this 'covers' the gaps I do not believe it creates an air seal.

Should I assume it will be sufficient to seal around and between these boards?

- It would increase the length of my sealing by ~ 50% since I would be doing two sides and a middle. (Not counting the ends which are negligible). However would be much easier than prying them up.

In Energy efficiency and durability | Asked By Charles Lee | Dec 1 16
1 Answer

Should I install my wood stove chimney through the attic?

I am instaling a wood stove for occasional fires and I want to install the chimney inside the house. It is really cold out here and the outside chimney I have right now conducts the cold into the wood stove and the stove becomes really cold when not in use.

I want to install the chimney through the first and second floor of the house but I want the pipe to make a bend from the ceiling of the second floor to exit on the side of the house instead of going through the attic.

Is this a good idea. I hear horror stories about chimneys going though the attic.


In Energy efficiency and durability | Asked By MF Houle | Dec 3 16
2 Answers

HVAC Multifloor return system - Should I get grills with dampers to control velocity?

I am designing the new HVAC system for my home. I plan to do a 4 zone system, lennox SLP98UH090XV60C

Attached is a diagram for a visual.

I am getting into the return ductwork. To my understanding it's good practice is to have a return grill on each floor and it will better circulate air. Also, I separated them into two zones to help with noise transfer between floors.

In Mechanicals | Asked By Jamie B | Dec 2 16
6 Answers

Can rigid insulation be safely used in the center of a double stud wall?

Joe Lstiburek's details for double stud walls show a layer of OSB/plywood in the center of the wall for an air and vapor barrier. Could a wall be assembled with R-13 batts in 2x4 framed walls, separated by a layer of 2"-3" rigid insulation? It seems like the first condensing surfaces of the rigid insulation would safely remain below the dewpoint, and foil faced insulation like polyiso would be a very effective air and vapor barrier. This would be built in climate zone 4.

In Green building techniques | Asked By Jason Whitacre | Nov 30 16
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