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1 Answer
Unvented cathedral ceiling

Hi everybody, at the cottage I have to replace the actual roof shingles and try to correct a problem with ice-dam, I want to install rigid Styrofoam board (1.25 inch) directly on the sheating then strapping over it and new sheet metal roofing. I wont be using a ridge vent since i'd like to make it unvented, also i'd like to leave the ceiling untouched if possible, right now the rafters are 2x8 there is only 3 inches of fiberglass bat in there whitout any vapor barrier. The pitch is a 3 to 12. So i'm wondering if I can do it by the roof only.

Asked By Pierre Brazeau | Apr 22 14
7 Answers
Wall section? Attic insulation? Energy / Moisture / Storm

All,

I'm a licensed GC designing an addition to my personal residence which we built in the late 80s. The original house was built with 2x6 studs and might very well have been the first house built in NC with a sealed crawl space. (I gave my building inspector a copy of a sealed crawl space article by the TVA, and he OK'd the sealed crawl space.)

I would greatly appreciate some input on a couple aspects of the design.

Thanks,

Bill

Project synopsis:

Asked By Bill Daugherty | Apr 20 14
46 Answers
Why must HVAC decisions be so complex? (Or... Is geothermal worth it?)

In another thread, my choice for HVAC was appropriately questioned. The system seems inordinately complex, costly, and convoluted. At least, on the surface. But digging deeper, the reasoning behind the design becomes clear. But, does that make it right? Is this the best HVAC design, or is it redundant and wasteful?

Here are the pertinents:
• Climate Zone 6
• 2700 sq. ft. finished space in story-and-a-half (bungalow style) house
• 2000 sq. ft. unfinished basement (future completion for aging parents)
• 4 Bdrm, 3 ½ bath house
• Tight, highly insulated home

Asked By Kent Jeffery | Apr 16 14
15 Answers
Pretty Good Wall Design - Maybe

Hello,
The attached file shows a wall design concept for a new house build near Minneapolis, Mn. I'm trying to design a wall that is both easy to build and has good performance.

Asked By Karl Overn | Apr 20 14
4 Answers
Retrofitting an uninsulated slab for radiant

We are planning a major renovation of our 1970s ranch and would like in-floor radiant heat. The house is on an uninsulated slab in climate zone 5A. Our current plan is to insulate with 1.5" XPS over the slab, lay Schluter Bekotec over the insulation, place the the PEX in the Bekotec, screed then tile thoughout the house.

Asked By Jessica Marchesi | Apr 6 14
1 Answer
Martin Holladay will be speaking this week in Montreal

Martin will be speaking on "Affordable Green Homes for Cold Climates" in Montreal, Quebec, at 7:00 p.m. on Friday April 25, 2014. The event will be held in Room 3110 at the School of Architecture at the University of Montreal. He will be speaking in French.

For more information on the event, visit the Maison Saine website.

Asked By Martin Holladay | Apr 21 14
12 Answers
REMOTE vs. PERSIST approach for a flat roof?

I'm not sure I fully understand, but the REMOTE system states an advantage over PERSIST by allowing more insulation in the roof and not building a second roof structure.

Does this advantage apply for a flat roof?

I'm also trying to understand whether a vapour permeable barrier is needed for the roof and walls on the outside of the sheathing, before the exterior insulation is installed. REMOTE promotes vapour permeable, and PERSIST uses impermeable.

Asked By Jerry Chwang | Feb 11 14
1 Answer
Installation of windows without housewrap

I live about 30 miles south of St. Louis and own a 2006 home that was built using construction techniques that are standard for our area, but far from using green building and building science principles. For example, our home was built without the use of exterior insulation or a housewrap, meaning we have our OSB/plywood followed by the vinyl siding.

Asked By Ken French | Apr 22 14
2 Answers
Roof insulation

I am rehabbing a house located in zone 5, Pennsylvania. The room I am working is a kitchen with a cathedral ceiling. The room is completely gutted. The rafters are 2 x 10 on 24 o.c. The roof pitch is about 15 degrees.

Asked By Anthony Jackson | Apr 21 14
1 Answer
Best HRV for a fire station that gets humid in winter?

I am doing a bid to fix a humidty problem in a fire station. This is in a small town in mid-Missouri. The building is a 2,840 square foot metal building with no ventilation. It is heated with radiant heat. It is 45,000 cubic ft.

In the wintertime the building is trapping all the excess moisture in the building and then it is condensing on the bay doors of the fire station and growing mold.

I am pretty certain that a good HRV will do the job but I'm not completely confident how to size it due to the fact the it is an extreme situation. Any and all help would be greatly appreciated.

Asked By Mike Hansen | Apr 21 14
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