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4 Answers

Horizontal roof strapping for ventilation?

I am building a 16'x24' house in Alaska, 12/12 gable roof using 2X12 rafters, with a cathedral ceiling. A friend has recommended venting the roof by strapping the rafters horizontally with 2x4's at 16" o.c., thereby allowing cross ventilation from gable to gable. The roof would be sheathed on top of the 2x4's. I haven't been able to find any information on this technique on the web.

In GBA Pro help | Asked By Justin Smith | Jul 15 13
37 Answers

Hello Martin: I have a question about insulation diminishing returns below. Thank you in advance for your thoughts.

I am working on a proposal to better understand diminishing returns on insulation. Our theory is that too little insulation wastes energy and equally, too much insulation wastes energy. Where is the sweet spot in each climate zone?
Attached is our proposal. We are interested in knowing if GBA has conducted any performance testing that makes diminishing returns conclusions. If not, we are hoping GBA might give us some advice that makes our experiment productive.

Opps. The file is too large to send. Could you e-mail me at anders@lewendal.com and I will forward you the file directly?

In Energy efficiency and durability | Asked By Anders Lewendal | Jul 8 13
2 Answers

Insulation for a slab on grade?

I am in eastern Ontario (Peterborough) and will be building a 2100 sq. ft. on a slab on grade... kinda....I am on bedrock and it is irregular with the low corner to high corner about 30 inches difference in level.My first thoughts were to build a stem wall of ICF and fill the inside with tamped gravel,.I would put down a vapor barrier and 2 inches of foamboard then pour the cement .I cannot insulate the ground around the perimeter of the stem wall ...should I put another 2 inches of foamboard against the ICF to compensate.... and is 2 inches of foam enough under the slab?

In General questions | Asked By bob holodinsky | Jul 15 13
2 Answers

What do these window ratings mean : I-55, A3, B5, S2, F10?

Windows with these ratings I-55, A3, B5, S2, F10 were recently installed in our building. Do you know what these ratings mean?

The landlord has made an application to increase the rent to a whopping 5.5% based on this capital expenditure (and other lower cost expenditures).

Previous windows were double paned and I'd like to know what benefits windows with ratings of I-55, A3, B5, S2, F10 have over previous double-paned windows.

Our hearing is this Friday July 19.

Also the wind load resistance increased to C5. What does this mean?

Please help. Thanks so much!

In Energy efficiency and durability | Asked By Ria van der Veen | Jul 15 13
3 Answers

Will closed-cell insulation prevent bricks (and the mortar) from drying out and eventually falling off of the wall?

My condo association says that closed cell insulation sprayed directly to the back of a brick wall will not allow the brick to dry because there is now airspace, and thus the brick will eventually fall. Is this true?

In General questions | Asked By Ryan Byrd | Jul 7 13
2 Answers

Sound isolation with an unvented attic?

We've insulated the roofline and exterior walls with spray foam insulation and put fiberglass in the interior wall studs, and double drywalled with green glue on bedroom interior walls, but there's still sound transmission between rooms since there's no insulation above the ceilings. Would adding roxul above the bedroom ceilings work? Would that cause any problems? Dust?

In General questions | Asked By andrew shu | Jul 14 13
1 Answer

Is creating positive pressure (post energy work) appropriate?

Good Morning:

In Energy efficiency and durability | Asked By Chip Goyette | Jul 15 13
4 Answers

This has to do with wall insulation in a partial re-build of a 19th cent. House in New Orleans

Climate is Deep South, or hot and very humid in the long Summer. I have heard and read that traditional batt insulation is practically useless. spray insulation is not an option !(for financial reasons) and it may, in any case, be a bad choice environmentally. Celluose . Does this product come in batt form? One further piece of info - the framing is wood on 16" centers. What choices do I have.
Thanks, Michael Higson in New Orleans

In Green products and materials | Asked By michael higson | Jul 12 13
8 Answers

Vinyl Wallpaper

I've been trying to educate myself on vapor barriers since they are by far the most complicated topic I've ever come across.

One thing that kept popping up is the notion that vinyl wallpaper is bad (except for very cold climates). It is a vapor barrier and thus keeps the walls from drying to the inside, right?

Suppose I want vinyl wallpaper in a climate zone 4 or lower. Suppose I like the look of it, and I still want air conditioning. What can I do to make sure it doesn't cause damage to the walls?

Thanks in advance for any help!

In Interior design | Asked By J S | Jul 11 13
3 Answers

Is it time to replace the filter?

I asked this at More Energy Myths a few weeks ago but haven't seen a response so I will post it here.

In Mechanicals | Asked By Bob Rinehuls | Jul 13 13
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