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!


1 Answer

Fresh air distribution for hydronically heated house?

Currently have a leaky hydronically-heated house.

I plan on removing the siding, installing blueskin VP peel-and-stick, then 2 layers of Roxul R6 ComfortBoard IS from the roof right down to the footings.

Because this should really improve the air leakage, how should I get fresh air in/out of the house to control humidity / air quality / etc?

Do people run a set of air ducts throughout the house from a HRV?

One of the appeals of using hydronic heating is that sound / dust transmission is significantly reduced.

What would you recommend??

Thanks!
.../j

Asked By John Charlesworth | Mar 26 15
2 Answers

Old house, wet brick

The picture pretty much says it all. We had terrible ice damming this year, as did just about everyone in my area; houses both old and new saw wet walls and rainy windows for the first time ever. My house was built in 1850, and I have to imagine this has been a problem before. But this was our first full winter here. I'll try to explain the situation as best I can:

Asked By Chris Ermides | Mar 26 15
6 Answers

Attic insulation reality check

It's time to get my attic air sealed and re-insulated and I've committed to hiring it out since the 6/12 pitch truss attic is a horrible place that I hate to work in. I'm having trouble finding people willing to blow cellulose. Everyone around here seems to want to blow fiberglass. Is this a major issue?

The first bid I've gotten is $3.20/sf for attic floor air sealing and R-30 worth of blown fiberglass. Sane/insane?

Asked By Nathaniel G | Mar 26 15
8 Answers

Insulating scissor truss

Hi, I am building my first house, what a project that has turned out to be but that's for another day. Anyways, our great room has scissor trusses for a nice pitched ceiling. I would like to have at least 24" of insulation to keep things nice and toasty in the winter. There is a 4' overhang outside on either end. I nailed a 24" high plywood leaving a vent space above where the red is on the layout. My question is what material and how to go about it. To use the high density cellulose is has to be contained by some mesh? Any input appreciated.

Asked By Tom Smith | Jul 19 14
8 Answers

Porch posts

We are building a wrap around porch that extends 6'. Since we know, because of code we have to use 6x6 for the posts for the deck, I have question about the posts that supper the roof.

One way is to use the same 6x6 and extend it from footer to header. We think that since these posts will be 6' apart going around the porch it might seem a bit too bulky.

Does code allow you to replace 6x6 posts with a PVC reinforced porch posts (they are turned and look like traditional porch posts)? Or do we have to stick with 6x6 lumber?

Asked By Matt Cibula | Mar 25 15
9 Answers

Dryer vent in air-tight Passive House

I am building a house in the Seattle area to Passive House standards. After spending countless hours sealing every crack, seam and penetration to achieve under 0.6 ACH, creating a 4 inch diameter hole in my air barrier pains me. I've looked into condensing dryers that are used in some European Passive Houses, but they seam to take much longer to dry and use lots of water. Since I will be installing a vented dryer (unless someone can come up with another solution), are there ways to make the dryer wall vent more air-tight when the dryer is not in use?

Asked By Gerald Blycker | Nov 21 14
3 Answers

Manual J - Calcs - Mini Splits

Zone 4B - 3,300 sqft - 2 story - R10/R25/R60 with R8 windows - open floor plan design

The calcs came in at 3.25 tons heating/cooling. Two ductless minis per floor:
3 - 9,000 Btu Mitsubishi Hyper Heat Pumps - 26 SEER - 10.5 HSPF
1 - 12,000 Btu Mitsubishi Hyper Heat Pump - 26 SEER 10.5 HSPF

$12,000 installed (P&L) for all units - 10 year warranty

Asked By Peter L | Mar 26 15
4 Answers

Insulating truss joists 16" on center — Best way?

Batt insulation for 24" o.c. The 2x lumber is 23" wide. The truss joists I'm looking at are 2x4 lumber 24" o.c. The space between the trusses is 21.5". Does anyone know if R-19 batts are available in 21.5 or 22"? Seems like squeezing a 23" wide batt will not work well.

Also the tiger wires used on 2x lumber will not work well on a truss. Is there another method of holding the batts up to the floor?

Asked By Walter Gayeski | Mar 25 15
7 Answers

Evaluating feasibility of solar panels in site rated at 895 (or 65% TSRF)

Just got a quote from solar panel install company and thinking I may skip solar and redirect funds to doing more insulation work on the house. But before I do that, I wanted to run some thoughts by here.

1. I am calculating that per kW I will be at $4.25 installed (I am in Boston area). Considering article I just saw today on GBA pegging average installed price $0.80 less per kW I am discouraged.

Asked By Apollo S | Mar 25 15
6 Answers

Strapping material for rainscreen...plywood fir or spruce?

I'm ready to put the strapping on-top of my WRB, only I'm not sure what the best choice is.

I want a 3/8" gap, so cutting plywood strips is my only option (there is NO composite furring strips available in town...I called everywhere!)

I've got the option of 3/8 spruce with exterior glue, or 3/8 fur with exterior glue.

Does either have a lower tannin content that may deteriorate the WRB? Do I even have to worry about that? Should I back prime the strapping to avoid this?

I'm going to put cement board over the strapping then stone.

Thanks!

Asked By Mark Helmrich | Mar 16 15
Register for a free account and join the conversation


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