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4 Answers

Crawlspace Vapor Barrier

In a recently flooded crawlspace,I have a concrete rat slab(approx 2 1/2" thick).However the slab has no vapor barrier under it.The slab itself is below outside grade about 18".I want to control the moisture level in this crawlspace.The crawlspace,doesn't get standing water in it,nor does the groundwater seem to exert any problems to it.The flood was a freak occurrence.

In General questions | Asked By Dennis Dipswitch | Mar 21 13
33 Answers

Calling all "rammed earth" experts...

I was recently thinking about "rammed earth" construction.
I found an episode of "The nature of things" where David Suzuki talks with a rammed earth builder that calls his approach "SIREWall"

The main innovations with "SIREWall" seem to be the inclusion of rigid foam insulation in a manner that appears similar to a Thermomass foundation and higher compressive strength than more traditional rammed earth techniques.

The performance/durability advantages as I seem them are:

In Green building techniques | Asked By Lucas Durand - 7A | Feb 18 12
1 Answer

Cooling and Dehumidifying With A High Velocity System (SpacePak) and HRV

I'm mid-project on a 2000 sq ft addition to an existing Victorian in Toronto, Canada.

For all intents and purposes the 2nd and 3rd floor addition are independent of the main and basement below. We have radiant floors off a HE boiler. Very tight house with R30 walls and R60 roof.

For a variety of reasons we've elected to cool using a spacepak and heat pump. There is an independent HRV going from bathrooms to bedrooms.

My questions are:

In Energy efficiency and durability | Asked By Evan Johnsen | Mar 21 13
12 Answers

Cost-effective insulation detailing for Sandy victims

I will be doing the rebuilding of 2 family member's homes that were heavily damaged by Hurricane Sandy.I have been in the building trades for over 20 years.

Both houses have been unoccupied since the storm.My advice to them was to procede with construction when sufficient money was available to do a proper project,not a pieced together hack job just to get back into a house.

In Energy efficiency and durability | Asked By Dennis Dipswitch | Mar 13 13
2 Answers

Plywood or ZIP sheathing

Our wall assembly will be 2x6 framed wall with cellulose, sheathing (ZIP or plywood), 2" foil faced polyiso (2 - 1" layers), furring, then hardiplank.

My first thought was to use the Zip sheathing for the the air barrier properties but now thinking I can get the same effect with taped seams of plywood.

Any opinions?

In General questions | Asked By Troy Stevenson | Mar 19 13
1 Answer

How to add more insulation on a cathedral (attic) ceiling

I am a homeowner in downtown Ottawa, Canada, with a typical 110 year old house. Roof slope is 12/12. The asphalt shingle roof is at the end of its life. I am considering a metal roof.

I am trying to figure out if it is worthwhile to add aditional insulation at the same time, and how.

The attic space is a finished 3rd floor, enclosed in 1993. The ceiling construction is
• 1/2" drywall and a six mil UVBA
• 5/8 unfaced phenolic insulation board laid crosswise to the rafters (R4.5)

In Energy efficiency and durability | Asked By Eric Darwin | Mar 20 13
3 Answers

"Scientific" Conversion from CFM50 to ELA?

I've seen divide by 18 in a few places, including this site. Is there a scientific paper that defines this number?

In Energy efficiency and durability | Asked By Nick Sisler | Mar 20 13
4 Answers

Insulating floor above vented crawlspace with cellulose

I am building a Passive House outside of Seattle in climate zone 4C. The building site has a high water table with water only 24 inches below grade in the winter after a good rain. I'd like to have at least R-50 for my floor above a vented crawlspace. The sub-floor will be the air barrier. The HRV, all duct work and the water heater will be above the floor in the conditioned space. I would like to use dense packed cellulose between the 18 inch deep TJI. I have concerns regarding the high water table.

In PassivHaus | Asked By Gerald Blycker | Mar 20 13
3 Answers

Venting under composite decking on a screened in porch

New house under construction. Initial plan was to have a polished concrete floor on a screened in porch. Concern voiced by a contractor was that the concrete may be slippery if it gets wet. Considering the use of composite decking in lieu of the concrete floor. Initial thoughts were to pour the base, affix pressure treated sleeper 2x2's with stainless tapcons to the concrete and then lay composite decking across the 2x2's. Concrete base would be sloped to allow moisture to drain through a weep system.

In General questions | Asked By Milan Jurich | Mar 19 13
1 Answer

Pros and Cons of different types of expanding foam for air sealing?

Hey there. I saw that in the last issue the magazine they did a "tape off" between the different types of tapes. Has there been anything like this for expanding foams used for sealing? There are quite a few on the market between the different brands....

I am asking because I need a foam for sealing between XPS and wood ceiling rafters. I would like something that is flexible due to the expanding and contracting as well as living in an earthquake prone area.

Any links for discussions on this?

In Green products and materials | Asked By Kevin Lauscher | Mar 20 13
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