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3 Answers

Open Cell vrs. Closed, where to draw the line

Here in NC we generally spray 8" to 12" of open cell insulation, generally Demelec or Icenene, on the underside of our roof deck. I am constantly asked about closed cell vrs. open cell and what are the considerations that would make one or the other preferable.

In Energy efficiency and durability | Asked By Michael Chandler | Feb 7 09
2 Answers

How do I seal a crawl space, with a below-grade basement with an existing slab?

I do a load of work retrofitting "new" green building practices into 80-100 year old homes. Sealed crawl spaces is a particular retrofit specialty, but even after installing a half dozen or so we still run into our head scratchers. See, here in the clay filled piedmont of North Carolina, no one builds basements on a flat lot. The drainage problems are too many. Of course, builders didn’t figure that out until mid-century, so there are plenty of historic homes stuck with below-grade basements.

I want to seal them. Here's how I want to do it:

In Green building techniques | Asked By Aaron Lubeck` | Apr 21 09
0 Answers

Are there any high-efficiency oil burners that will burn pure biodiesel as well as the biodoesel blends?

I am in the process of searching for a new oil fired boiler to replace my old one. Natural gas is not available to my site so I would like to install a boiler that would allow me to burn pure cellulosic biodiesel or if unavailable at this point, a biodiesel blend. At this time I am researching Buderus and Viesman boilers. Is there any other make of boiler that you would suggest, and what is your opinion of Buderus and Viesman.

In Green products and materials | Asked By Edward Palma | Apr 22 09
2 Answers

Cold climate building envelope question - Adding styrofoam to the outside of the wall

- possible condensation issues, i.e. a second vapour barrier created in the wall cavity. Assuming the typical situation where a poly vapour barrier is installed behind the drywall and fg insulation in the stud cavities.

In Energy efficiency and durability | Asked By Wm Smith | Apr 20 09
5 Answers

Energy Efficieny upgrades for historic buildings

I have a project that entails the rehabbing of over fifty small historic buildings for energy efficiency and comfort upgrades. Because these buildings are part of a National Historic Landmark, we are very limited to how we effect the exterior of the structure including window changes. My plan is to start with insulation upgrades to the attics and crawl spaces. Funds are limited as this is part of a non-profit organization so I want to be sure to spend the money wisely.

In Energy efficiency and durability | Asked By Jeff Medanich | Mar 11 09
1 Answer

Can I use 3/4" foil-faced and backed rigid insulation as an insulation baffle?

...for venting a roof with a soffit-to-ridge venting system?

In General questions | Asked By Mike Schilke | Apr 21 09
1 Answer

Frostproofing an existing slab on grade

I am a residential designer working out of northern Wisconsin. I have a project I am working on that has an existing house with a full basement built about 10'-0" from an existing slab-on-grade garage. I would like to attach the garage to the house with a breezway-type addition. Is there a way to frostproof the existing garage either by digging down 4'-0" vertically & sliding rigid insulation into the trench, or I believe I have seen shallow frostproofing where rigid insulation is laid horizontally just below grade out to a point out 4'-0" from the edge of the slab. Or a combination of both?

In GBA Pro help | Asked By jeff hibbard | Apr 20 09
1 Answer

What green roofing material is best in New England? What is the cost & who has used it?

We have a 30 year old contemporary home with original asphalt shingles which we will need to replace. What happens to these shingles after they are taken off the roof? Are they recycled or do they head to the landfill? There seems to be pros and cons to all products out there. Has anyone used the rubber shingles which mimic slate?
Thank you for your input.

In Green products and materials | Asked By Maria Hars | Apr 21 09
1 Answer

Fiberglass over a slab

We are bumping out the garage and turning the exiting garage in to a family room. In the process we are framing on the slab to meet up with the floor in the house. We have put down a vapor barrier (6 mil plastic). The plans call for R19 Fiberglass in the cavities. My concern is condensation within the system (tile will be the finished floor.) also should this space be vented in some manner as well? This project is in Wisconsin so there is a great deal of temperature change. I feel that we should be putting down minimum 1” foam and air sealing all joints.

In Energy efficiency and durability | Asked By Richard Monserud | Apr 20 09
1 Answer

Can I add 2" rigid insulation at exterior of the building and keep existing windows?

I am working on the renovation of an existing commercial building. We would like to add 2" of rigid insulation and a drainage plane to the building, but we plan on keeping some of the existing awning windows that are in good condition. Can I furr out around the existing windows? Or do I need to relocate the existing windows to the new exterior plane of the wall? I am concerned about the weak point for water infiltration at the window sills. I am using xps foam, blocking as required, and p.t. strapping. We are installing new fiber cement siding and new trim around the windows.

In Green building techniques | Asked By maura o'dea | Apr 16 09
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