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1 Answer

Band joist insulation (first floor ceiling / second floor floor)


I know that the best approach to insulate band joist would be using spray foam / foam board + spray foam sealing the perimeter. However, the builder has already put in fiberglass insulation along the band/rim without air sealing - would this cause condensation problem? The building is in zone 5.

Thank you for your help.

In Energy efficiency and durability | Asked By Kin Chan | Mar 6 16
4 Answers

Installing rigid mineral wool on the interior of studs


We have an old addition on our house that would benefit from additional insulation. It is stripped to the studs at present, from the interior, and the plan is to spray an inch of foam and the remainder of the cavity with cellulose (the combo is for reduced sound transmission). I would like to add additional insulation on the interior surface of the studs. Access to the exterior would be difficult. I am wondering about adding 1" rigid mineral wool.

In Green building techniques | Asked By Douglas Wathen | Mar 6 16
4 Answers

Shower sheeting on exterior wall and general ceiling finish

Climate Zone 5B in southwest Colorado. Ready to sheetrock interior with 5/8" type X.

The exterior walls are: corrugated metal / 2x3 strapping (rainscreen) / tyvek / 2x4 studs & R15 roxul / 3.5" gap & R15 roxul / 7/16 osb taped air barrier / 2x6 studs & R23 roxul / sheetrock air barrier #2.

Question 1 - Is it ok to sheetrock the wall in the shower area (seen on the left side of the photo where the pan depression is) given that the shower will be built using Tru-Gard or Schluter shower wall system, or should wonderboard be used, keeping in mind the sheetrock is air barrier?

In Green building techniques | Asked By Chuck Jensen | Mar 5 16
7 Answers

Radiant heat insulation between conditioned floors

Hi, I read your article questioning the need for radiant heat on a second floor. My question/concern relates to this but is particular to my situation.

I have installed radiant floor heat (not yet charged or insulated) in the first and second floor (separate zones) of my old farmhouse. I have all new low e windows and will be using spraying poly on the walls. The house will be tight! My contractor thought I may never use my second upstairs zone particularly, since I've also plumbed in a wood stove on the first floor. The bottom floor is 800 sf and the second is only 400 s.f.

In General questions | Asked By w n | Mar 5 16
4 Answers

I'm not sure that my building inspector understands the science

I live in climate zone 4A (near Philadelphia, PA) and I am building a 2400 sq ft addition on the back of my house. From the outside in, my wall assembly is vinyl siding, rainscreen, 2" XPS rigid foam, zip-system sheathing, 2x6 stud framing with Roxul insulation. My building inspector says that I must have an interior vapor barrier. To the best of my knowledge (and research) with the exterior XPS on the wall, the interior of my wall should be vapor-open. I'm not sure that my building inspector understands the science behind leaving the interior vapor-open.

In Green building techniques | Asked By Ian Doherty | Mar 5 16
4 Answers

Down South cathedral ceiling insulation confusion

A little bit confused most everything I find is for northern climates and the little info I have found for my climate seems to contradict one another. Need some help to figure this out.

I'm in zone 2a, central Florida. The house is an octagon in an octagon with the main floor roof about halfway up the 2nd floor/loft walls, sitting on top of the garage/basement. Except for the 3 bedrooms and baths the entire house has cathedral ceilings covered in cedar planks.

In GBA Pro help | Asked By Gerald DeArman | Mar 4 16
2 Answers

Differentiating high solar gain and low solar gain windows

This question is related to a recent thread on measuring performance of existing windows.
Is a solar incidence meter/heat lamp setup a reasonable way to differentiate high solar gain and low solar gain windows? The solar meter is sensitive from 400 to 1100 nm (but not a flat response curve) and readings were taken at a baseline and then with glazing between the lamp and the meter. I understand that the measurement may not be accurate in terms of absolute SHGC but am I correct in assuming that there should be a measurable difference in the % transmission under these conditions?

In General questions | Asked By Rob Myers | Mar 5 16
5 Answers

Detail for covered entry door and exterior rigid foam with brick veneer

Hi all,

There is plenty of discussion out there about proper techniques for window installation on thick wall construction, but not much, if any, for door installation.

Here's my situation...

I'm going to have an entry door, flanked by sidelights, under a full covered porch, on a house with 2x6 studs and 3" of exterior rigid foam, then an air gap, then brick veneer.

In Green building techniques | Asked By Clay Whitenack | Mar 4 16
4 Answers

Wet basement OSB. Remedy?

I started finishing my basement and noticed slight mild behind the vapor plastic barrier. After removing the plastic, the insulation between the studs, i noticed the OSB was sopping wet. Basement is half exposed and this occurs above the ground level.
I don't understand the cause but would like to determine a solution and move forward with the remodel. Advice?

In General questions | Asked By Jason Krahn | Mar 4 16
2 Answers

Air leaks, overlooking the obvious

I'm confused why the air lock style entry systems are not incorporated into more homes. An open door leaves a big passageway for the rapid exchange of air. Why don't prized and awarded homes incorporate this feature more often into the design? A busy house no matter how tight when the door is shut is subject to much cold every time Johnny comes in and out.

In Green building techniques | Asked By Hal Sartelle | Mar 5 16
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