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9 Answers

Improving attic insulation in 1.5 story Cape


I just bought a Cape in zone 5A in NH which has two rooms upstairs, splitting the attic into three zones. The side attics, and the space above the rooms. The space above the rooms is vented with gable vents on the ends and a continuous ridge vent. The side attics are my concern. One side appears to be completely sealed, and has 'balsam wool' insulation in the rafters, completely filling the rafter depth. It seems to be in decent shape but there are some holes and insulation falling out here and there. Under the floor boards there are some batts but the coverage isn't perfect.

In Energy efficiency and durability | Asked By Dustin Hotaling | Mar 29 12
5 Answers

What are the pros and cons of using PVC trim on the entire house as opposed to a quality wood product?

What are the pros and cons of using PVC trim on the entire house as opposed to a quality wood product? If wood, what species?
I'm not sure of what type to use. Hearing different opinions in regards to movement and times of seasons to install due to movement etc....

In General questions | Asked By Timothy Hickey | Mar 17 12
8 Answers

Which surface is most effective for low-e coating in 2-ply laminated glass?

Which surface is most effective for low-e coating in 2-ply laminated glass. I am using it in Thailand (sunny and hot). Some says that I should use on surface 4 because low-e can not work if it does not contact to the air. But there are some cases that use on surface 2. Which surface is better?. I also would like to know how the kinds of coating (soft coat and hard coat) affect in this case?

In Green building techniques | Asked By Puri Tammarongtam | Mar 26 12
1 Answer

Covering Paint with Non-VOC Paint?

My painter used regular paint instead of the no-voc product we picked. Is it worth having him cover it with the no-voc paint? Or is it better to just leave it as is. Given that "no-voc" paint probably still has some VOCs, we don't want to add more VOCs unless it would provide some type of sealing benefit over the VOC paint. thanks

In General questions | Asked By Brian Jackson | Mar 28 12
1 Answer

Redwood siding corrodes building paper?

I recently moved into a redwood-sided house built ca. 1992 in climate area 5A (midwest). I have have problems with leaking roofs - i thought - until the roofer took off some of the siding below an area where two parts of the house come together - to find that the building paper was corroded, the sheathing completely rotten, and studs and sill plate partially rotten too.

In GBA Pro help | Asked By Katie Grigg | Mar 28 12
7 Answers

Pier foundation - how much space would the plumber, HVAC people prefer?

We will be building a house for my brother in Upstate SC next year. We are currently in the design phase and having a disagreement on where to put the downstairs kitchen and bathroom with the plumbing lines.

I am thinking along the lines of what makes the house the most resilient and easiest to repair and who knows what he is thinking. The house will be on a pier foundation because it is near a flood zone. The land is sloped so that the piers at the driveway side will allow a crawl space of 3 feet or so and probably 6 feet at the other end near the pond and the flood zone.

In General questions | Asked By Lucy Foxworth | Mar 26 12
5 Answers

Website improvements

GBA is working on some website improvements, and we're encountering a few glitches on the way to a better future.

Today's problem includes the occasional blank line that appears (unwanted) in the middle of a sentence, usually after a glossary term. We're working on fixing the glitch.

Please bear with us as our team works on solving this software code problem. And if you want to draw our attention to any other irritating glitches, please do -- by posting a comment here, or by e-mailing me:
martin [at] greenbuildingadvisor [dot] com


In General questions | Asked By Martin Holladay | Mar 6 12
2 Answers

Is it worth the effort? Attic insulation detailing.

My home is a 1950, 2 floor, brick colonial in the Detroit area (5A). This place was built with no wall insulation. There is still no wall insulation.

In Energy efficiency and durability | Asked By GARY ZIRULNIK | Mar 26 12
1 Answer

Thermal Bridging of I-Joists

Building living space over a garage (zone 5-Colorado).
Floor will be 12" I-Joists (3/8 web) with blown cellulose (R-42).
Roof will be 12" I-Joists with blown Cellulose (R-42) plus 2' foam (R14).

Given that the delta T (garage to Living) is only about 40 degrees, do I need to worry about thermal bridging with R-42?

Second question: Have seen a couple double wall projects where the inspectors required 3/4 plywood fire stop every ten feet. Wouldn't this diminish the advantage of double wall?

In Energy efficiency and durability | Asked By Richard Patterman | Mar 26 12
2 Answers

Mass. glazing requirements for school buildings impede energy efficiency

It appears that Massachusetts now requires low solar heat gain (below 0.4) for windows in school buildings constructed with state aid:


The SGHC must be no higher than 0.4, according to page 186 of this document.

In Building Code Questions | Asked By rich cowen | Mar 26 12
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