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6 Answers

Filtration and humidification with mini-split systems

I have a customer with allergies. Her existing GFA furnace has a high efficiency filter and a humidifier.

In the new (air sealed and super insulated) home we are designing for her, we are planning to use Fujitsu mini-splits for heating and cooling and a Honeywell ERV for ventilation. Specs for these units indicate a washable filter but no MERV rating.

In Mechanicals | Asked By Terry Herschberger | Mar 23 15
3 Answers

Thicker walls

I live in Minnesota. I'm remodeling an older home with full 2x4 studs. On the outside there is a layer of 1 inch buffalo board and 1 inch foil covered foam.
Is it worth the time and money to add wood strips to the 2x4's to make them 2x6's on the inside and go from a R-15 to R-19 or 21 insulation or add 2 inch certifoam to the outside or should I just leave it alone with 2x4 walls and R-15?

Thank you

In General questions | Asked By Scott Neels | Mar 22 15
3 Answers

Foil tape inside duct?

I have several heat registers that I can access the duct from the inside only on, a few as far as 2 feet into them. Some just have seems, one has a good 1 inch gap on one side. (I'll try to hammer that together from the inside.)

Anyway, I've read that mastic can dry out on the inside of ducts, but have read conflicting suggestions about foil tape. I have this tape right now, should it work on the seems inside the duct, in the last 2 or so feet before the register?


In Mechanicals | Asked By Jeremy M | Mar 23 15
2 Answers

thicker walls -- [Not really a new thread]

The interior is gutted to the studs. Was going to replace old isolation with R-15. Will be residing in the future. Vinal is brittle and we are replacing all windows. Doing all the work myself so it's just what I think I'm worth.
Thank you

In General questions | Asked By Scott Neels | Mar 23 15
2 Answers

Hard or flaccid?

I am advising my friends on their 50s ranch upgrade with full basement. The house could never be made energy efficient unless it was completely torn down and rebuilt. They have a lower seer HVAC system that is a tad bit over-sized and runs like a top. Their GC wants them to completely rip-out the very accessible (full basement) hard HVAC duct and install a new system for 16k+ not including 18% markup (estimate with no manual J or D, to go by I might add), because their system is "too leaky" which he summarized by just eyeballing it.

In Energy efficiency and durability | Asked By leo kloop | Mar 23 15
9 Answers

New PHIUS+ 2015 released and in effect as of March 16th, 2015

Interested to hear comments on the new PHIUS + 2015 that went into effect on March 16, 2015. They made a lot of changes and the biggest being the each climate zone and specific area will have its own standards. Not one big gigantic fits all approach like PassivHaus but very specific to climate zones, house size, etc.

Read more here:

In Green building techniques | Asked By Peter L | Mar 20 15
0 Answers

Question re furring strips, XP drywall, and finishing basement over 3" of polyiso

I have used recycled roofing polyiso panels (1.5" stuff), staggered them, and going to foam the gaps where I can and use acoustic sealant ("the black death") on gaps too small for foam.

Here is a big question, I want to put furring strips horizontally and just mount drywall over that:
1. Is it OK to just go with furring strips and not build out full 2X3 or 2X4 framing. Wasn't planning to fill the gap with anything between drywall and polyiso

In GBA Pro help | Asked By Apollo S | Mar 23 15
2 Answers

Insulating basement ceiling/first floor

I suspect this has been much discussed, so feel free to bump me over to a thread if one exists...

We have a relatively modern (1981), reasonably efficient gambrel in Maine. Full basement, concrete foundation, unfinished (used for storage and a workshop. Not heated, but gets residual heat from the oil boiler. Temp hovers between 50 and 70, depending upon what the boiler is doing.

In General questions | Asked By John Gold | Mar 23 15
1 Answer

What is the best material for the underside of a porch?

Currently the underside is bead board. After this winter in the Northeast it split from ice dam buildup and 2' of snow sitting on the outside overhang 8' by25'. The style of the house is a New England farmhouse. I understand their are two thickness' of wood beadboard, PVC. I'm a little reluctant to use the wood because of possible moisture. The orginal was but up in the 20's. Replaced with new in2014. The thin wood type.

In General questions | Asked By John Spears | Mar 23 15
19 Answers

Air sealing, flashing questions

I have to say that reading GBA for 4 years certainly helps when you build your own house (my brother's house, really), but it does not replace actually getting your hands dirty or sticky. I use the term sticky because my job is air sealing and I get covered in sticky stuff daily.

I have a few questions because I am not sure that I am doing things correctly. I don't really "get" flashing. I know you are supposed to "think like water" and ask yourself where would the water go and how to divert it to the outside of the building, but some details still baffle me.

In General questions | Asked By Lucy Foxworth | Aug 25 13
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