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

[Click map to enlarge]

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

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!


8 Answers

Should I install electric tankless hot water, a heat-pump water heater, or solar hot water?

So I'm in the process of specing out and finishing design on a Deep Energy Retrofit/Whole House Remodel on an old 1858 farmhouse.

House Demographics
We are in Zone 6a - NH.
PERSIST Technique is being used throughout.
R20 slab/R20 Sandwich Foundation walls/R40 above grade walls/R60 roof
We will have 9.3 kW of PV solar, and our current plans include two Solar Thermal Panels and and 80gallon Steibel-Eltron Water Heater/Storage Tank for our domestic hot water.....

In General questions | Asked By brad hardie | Jan 23 15
11 Answers

Longevity of double wall construction?

I'm currently designing a new home as an owner/builder (construction to begin later this year) for the Edmonton, Alberta area. I have several years of building experience, however I have to admit that I've only ever done status quo jobs - 2x6 construction with fiberglass batts, a poly vapor barrier and OSB sheathing.

In Green building techniques | Asked By Matthew Sokalski | Jan 23 15
5 Answers

How to insulate a block house?

i am rebuilding a small block house with a full basement in Northern Ohio. After researching the forum it seems like the consensus is to insulate the outside. My concern is that moisture in the walls from the ground or footings/slab will need to escape to the inside of the house since the rigid insulation XPS will create a vapor barrier on the outside. Any feedback or suggestions will be helpful. Jay

Buildintegral@gmail.com

In General questions | Asked By jay cooper | Jan 23 15
4 Answers

Closed crawlspace ventilation choices

I'm in the process of closing my 900 sqft crawlspace and need to find a way to ventilate the space. One thought I had was to use the old oil furnace chimney/flue as a way to send the air up and out with the help of a small(20cfm) bath fan. The flue is centrally located and close to an existing outlet. Or is it better to seal the flue (or remove it all together) and duct the air through the foundation wall.
Particulars:
zone 4 asheville nc
house built in 1969
neighbor had his crawl space tested for radon and was negative.
13mil barrier sealed to block wall

In Energy efficiency and durability | Asked By terrell whitworth | Jan 23 15
2 Answers

What is the best heat-pump water heater for Zone 6A?

So you guys have more than convinced me to go with a heat pump water heater. I am going to have 9.3+kW on my roof. Should I just buy a heat pump water heater or buy a Marathon type electric water heater and add on a heat pump?

In General questions | Asked By brad hardie | Jan 23 15
1 Answer

Roxul Comfort Board vs. Thermafiber RainBarrier

Any differences I should be aware of before I choose? I am wanting to use mineral wool for exterior insulation on a wood frame, two-story dwelling. Very impressed with Roxul online information, technical specs etc. Can't find much about RainBarrier, other than the company info sheet, but it's 1/2 the price of the Roxul. Thermafiber says that the Rainbarrier HD is the product they have made to be comparable to Comfort Board, but cannot find any comparisons between the two.

In Green products and materials | Asked By Caitanya Joy | Jan 23 15
4 Answers

Slab on grade floor repair

About 20 years ago two rooms were added onto this house, both have a slab on grade and the floor tiles are cracking, i had to repair a wall in one of the rooms, and it looks like the floor was the slab with a styrofoam sheet on top (2-3 inches thick), with 1/4in plywood, black adhesive (tar?) and kraft tiles on top (i have no idea what these tiles are called, they are 12x12 in, used in many schools and older buildings, are less then 1/4 in thick and are the same fibrous material all the way through (and i'm hoping not asbestos, they were installed about 10 years ago i am told).

In Green building techniques | Asked By Alan B | Jan 22 15
4 Answers

Whisper wind exhaust only ventilation durability with continuous run time?

Don't believe any of us know how long a Panasonic Whisper wind fan can be expected to run if exhausting 60 CFM out a bath ceiling if hard wired to operate continuously through time? Anybody have a guess?

In Green products and materials | Asked By Rick Jenkins | Jan 22 15
12 Answers

Ventless heat pump clothes dryer

Would a ventless heat pump dryer contribute to indoor humidity and heat levels?

I thought the unit was all self-contained and would NOT contribute to increasing moisture and heat in the room it was located in. If anything, it would only dispense water from the drain line into a sink drain but that's about it. Am I wrong?

In General questions | Asked By Peter L | Sep 5 14
2 Answers

How to insulate a partially open unvented ceiling/roof?

We've had a leak and ceiling damage in a 50 yr old house with a flat roof in zone 4A. Part of the ceiling is gone, damaged, part still intact with its fiberglass.So there are cavities with part fiberglass. There is no ventilation in the cavities. This part of the roof was re-roofed a few years ago and some sort of foam board was added on the exterior (presumably between the old rubber and new TPO) at that time. The is no condensation currently with the cavities open.

In Green building techniques | Asked By Katie Dorst | Jan 23 15
Register for a free account and join the conversation


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