Q&A: A Forum for Green Building Experts and Beginners

Q & A Instructions

[Click map to enlarge]

The GBAGreenBuildingAdvisor.com web site has a wealth of articles on a wide variety of construction topics. Before posting your question, you may want to check out the articles on this page: How To Do Everything. You just might discover an article there that provides the information you seek.

Please register for a free account or sign in to ask and answer green building questions.

If you want to post a question, the usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration: Under the box labeled “More explanation,” look for the words “File attachments.” Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


4 Answers

Retrofit vented attic to... unvented?

Quick question for the board members... Currently in the prep phase for a second story addition to one part of our house, that will entail splicing into the existing roof for roof/wall flashing as well as some structural improvements to a few rafters..

The current roof structure is 2x4 rafters, sitting on the wall top plate with birds mouth cut... so... Effectively, 1-2" of insulation if i'm lucky.

In Energy efficiency and durability | Asked By John O'Brien | Apr 10 16
4 Answers

What are long-term maintenance costs for ductless minisplits?

I'm not concerned about annual clean-the-filters type maintenance, but more about "What if a power surge blows a mother board?" type issues. My sister has had that happen twice, although it may be partially due to a poorly grounded electrical system. Other issues might be refrigerant leak or motor failure.

Does anyone have the kind of long-term, multi-installation experience needed to address this type of issue?

In Mechanicals | Asked By Robert Fankhauser | Apr 11 16
2 Answers

Radiant heat in an old house remodel

Hello,
I am looking at potential radiant options for an old farm house. Probably just the first floor at this time. My concern is we want to keep the original wood floors- so that means that we are looking at 1" plank subfloor and a <1" finished t & g flooring. The house is about 70-80yrs old. Is this too much/thick for practical radiant heating? I would imagine it would require more/higher water temps and be less responsive?
Thanks

In Mechanicals | Asked By Steven Mikel | Apr 12 16
39 Answers

Earth tube ducted through thermal mass concrete wall

OK, here's the basic idea. I would like to use an earthtube system to bring fresh air into a very tightly sealed home.

I'm also designing the home with a "solar stairwell", a stairwell that's exposed to the sun with big windows, with the back wall of the stairwell being made of dark-colored cast concrete.

During cold months, the concrete wall acts as thermal mass, gathering heat during the day and shedding it during the night. Exterior louvered shades above the big windows would keep this wall from getting direct sunlight during the summer.

In Green building techniques | Asked By Daniel McKinney | Apr 4 16
12 Answers

Tilt turn windows with good visible transmittance

Can anyone recommend manufacturers of quality, energy efficient, tilt turn windows with good visible transmittance. If I'm going to put a hole in my wall for a window, I don't want to fill it with a thick frame and dim glass. The NFRC website lists 64 manufacturers of tilt-turn windows, and I don't know where to start. I'm designing for zone 5. I am cost sensitive, but willing to pay for quality.

--John

In Green products and materials | Asked By John Ranson | Sep 24 15
5 Answers

Venting a flat roof properly

I have an existing house with a flat roof with an an addition that has a shed roof on one side that blocks the vents on one side. The shed roof addition stands 8ft above the flat roof. The original construction had fascia vents on both sides of the roof, but when they built the addition they blocked one side. I am renovating the addition portion of the house and plan to use closed cell on the walls and ceiling.

In Energy efficiency and durability | Asked By James DeSalvo | Apr 10 16
1 Answer

Insulating a sloped open space

How would one place cellulose in a large 2' tall sloped (4:12) under roof space with a smooth sloped floor and ceiling and no internal framing? Assume that ventilation is taken care of elsewhere. My biggest concern is keeping the insulation where it belongs.

--John

In Green building techniques | Asked By John Ranson | Apr 9 16
2 Answers

Insulation and vapor barrier between floors?

Hello:
I have built a two story cape cod in zone 6a. Normally I would not consider insulation between floors but, I only have enough cash to finish one floor and plan to live in the house this way for a few years. The heating system is radiant heat, 2 zones upstairs and two downstairs. It is the Onix 3/8 radiant hose stapled tight under the Advantech floor with a 3" gap then the foil faced bubble insulation.

In Energy efficiency and durability | Asked By Mike Shultz | Apr 9 16
2 Answers

How should I insulate an octagon gazebo roof?

I am designing a 15' Octagon Gazebo that will be a three season building with a door and windows. I am designing it with a 6' cupola to accommodate a 52" ceiling fan. The roof designed (2 by 8 rafters) is open with no ceiling joist.

This will be an "unheated" room, but I could see us using a space heater in the spring and fall to enjoy the gazebo a little longer (live in Minnesota). I was thinking it would be nice to have some roof insulation to keep the room from heating up too much in the summer. Can I insulate? If so what is the best option?

Thank you for any advice!

In General questions | Asked By Timothy Baube | Apr 9 16
7 Answers

Can you place an electric on-demand hot water heater in line with a tanked hot water heater?

I was given an electric on-demand water heater. I have an extremely long run and it takes quite some time for the hot water to reach the kitchen sink. I was thinking of placing the electric heater inline--that way we would not be running the water down the drain waiting for the arrival of hot water. I am thinking than the electric hot water heater would stop heating once the thermostat sensed the water was hot enough going through the coils. Not certain though...

In Energy efficiency and durability | Asked By Gregory Jones | Apr 11 16
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!