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9 Answers

How do I determine the size of a ductless minisplit?

How do I determine the size of a ductless mini-split Heating and Cooling for my new to me Cottage type home built in 1925.

It is 36 feet wide by 26 feet deep. It is an open ceiling type to the roof rafters about 12ft high at the center peak with R-19 insulation, the walls are R-13, Two inside rooms/divider walls with no ceilings (open concept).

The two side outside walks and the front wall get no sun there Is total of 9 double pain windows on these walls the back wall 30ft long has 10 single pain wood frame windows that slide open from right to left.

In General questions | Asked By Mitchell Thompson | Nov 1 16
7 Answers

Is this a valid way to measure heat load?

Our manual J calculation said that the heat load of the house is about 30K at about 65 degree delta T. (It was more precise than that but I don't have the report handy, so I am going from memory.) I am hoping to confirm that the actual load is not too far away from that before we get into really cold weather.

In Mechanicals | Asked By Reid Baldwin | Dec 5 16
18 Answers

Another crawl space in the Northwest

Hello all, I have a 1150 sq ft rambler house in Fall City, Washington (near Seattle), zone marine 4c. I am currently in the process of redoing the crawl space. I have pulled the damaged and rodent infested insulation down, and removed the town vapor barrier. It seems I had some rodents that were digging past the foundation and getting into the crawlspace, ruining everything.

In Energy efficiency and durability | Asked By David Meyer | Nov 28 16
14 Answers

How to employ a mixing valve in a closed loop radiant heat system

We are just wrapping up the new roof on my project house and now its [past] time to turn our attention to HVAC - or, more specifically this time of year, Heating! This 1975 house came with radiant heat ceilings as the only source of heat. Recently we have been having night time lows in the teens and daytime highs here in Northern Nevada zone 5 at 5000 feet are usually in the 40's. I have done some preliminary calcs on heat gain/loss, and plan on doing a full Manual J model before laying out any cash for components.

In Energy efficiency and durability | Asked By Roger Smith | Dec 1 16
1 Answer

Rodent-proof soffit vents

Hi,
what is the best way to create a rodent proof soffit vent air intake? I am looking for really durable products. My concern is that rats and squirrels could eventually gnaw through even hardware cloth. Any stainless steal products that people can recommend? Thank you very much.

In General questions | Asked By Matthias Paustian | Dec 5 16
11 Answers

How important is a thermal break between a house foundation and an attached garage foundation?

Our footings were poured today for a new house and attached garage. The walls of the basement foundation (9') and garage foundation are scheduled to be poured next week.

Looking over the plans, our concrete sub is worried about the 7" thermal break between the basement and garage foundations (no physical connection) as currently drawn on the plans. The separation is there in order to allow us to attach 5" of Roxul Comfortboard 80 to the basement foundation (we'll be doing the same for the whole exterior perimeter of the basement foundation).

In Green building techniques | Asked By Eric Whetzel | Dec 2 16
3 Answers

Insulating an unvented roof

I'm looking to finish the ceiling (underside of roof rafters) in a workshop/barn that is only heated when occupied. I'm in IEEC zone 6 (upstate NY) so it gets cold. Can't pull off the roof because it's relatively new and in great shape. Any work has to come from the inside. Right now there's a double layer (6") of rigid polyiso insulation in each rafter bay. The insulation if faced on both sides with fiberglass impregnated black paper (nasty stuff). There's also about 3" of open space between where the insulation stops and the edge of the roof rafters.

In Energy efficiency and durability | Asked By David Wittner | Dec 5 16
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
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