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2 Answers

Damp proofing for deck pilasters

I have 9 20"x20"x96" concrete pilasters on footings to be used as supports for my deck and the columns supporting the roof over that deck. Some of these are almost entirely below grade while others are primarily above grade. Do these pilasters need any sort of damp proofing to prevent freeze/thaw spalling? This is a new-build that will have appropriate drainage in Denver, CO in sandy/clay soil.

My opposing thoughts on this subject are:

In Energy efficiency and durability | Asked By Tony Arcuri | Feb 15 18
3 Answers

How to deal with metal roof condensation?


I have a detached 20' x 23' two storey garage, 100 yrs old, with an open room on the upper floor. The metal roof has a fairly serious condensation problem in late winter/Spring.

I'm in Climate Zone 6 - Montreal, Canada.

The current roof is an exposed-fastener steel corrugated gable. Around 2:12 - 3:12. The metal is screwed directly to purlins, on top of rafters, with no sheathing or underlayment. The attic floor is sloped old wooden boards covered in tar paper (I believe this was the original built-up flat roof). The additional gable structure was built on top of it.

In General questions | Asked By Leo Singer | Feb 15 18
10 Answers

Rigid insulation beneath floor on shed


First time posting and would like to thank you in advance for at least taking the time to read this.

I am building an insulated shed/writing studio for my wife. Looking to make it 12'x8' and was thinking of building it on concrete blocks with 2"x6" studs for the bottom frame. On top of that I was planning on 2" rigid insulation followed by plywood then flooring. Will I be able to put the sill plate on top of this and drill through to the 2"x6"'s? I haven't worked with rigid in this context before.

Putting it on blocks seems the best option in case we wish to move it later.

In Green building techniques | Asked By Allan Manley | Jun 22 17
2 Answers

Brick weep retrofit

Quick intro, I'm an architectural & hvac designer for a engineering firm in Ontario. Before that I worked for a carpenter with a knack for great details and learning from mistakes for all my early years. I'm re-insulating an existing 1970's home in Stirling Ontario. See the attached photo for a wall section. I've run into an issue. There are no existing weep holes and from exterior examination, it would appear there is no flashing. I cannot confirm the existence of a drainage space either.

In Energy efficiency and durability | Asked By Yupster | Feb 15 18
3 Answers

Attic access door recommendation

In my new build i want access to the attic space via a kneewall. What options are there that will provide a good seal and r-value?


Mixed Humid


In Energy efficiency and durability | Asked By Norman Bunn | Feb 14 18
4 Answers

Water-resistant insulation

We are rebuilding many small buildings (Not Houses) that were flood damaged by Hurricane Irma and have a small probability of flooding again. They are 2"x4" framed walls, sheathed with 1/2" plywood, covered with #15 building paper or house wrap and sided with vinyl or cement board. Remediation work included removing all wet drywall and fiberglass insulation, cleaning and disinfecting the wall cavity, and drying the framing lumber and sheathing to a moisture content of 8% or less.

In Energy efficiency and durability | Asked By Anthony Swoope | Feb 14 18
4 Answers

LSL Framing

I'm planning on building a small cabin with some laminated strand lumber (LSL) framing. I'll be doing 24 inch on center, so I'm going with LSLs for some additional strength. Straighter walls and easier installation are added benefits too. LSL lumber is very expensive, so I'd like to just use them for the studs and then use standard dimensional lumber for top and bottom plates. I'm trying to find a cost effective way to incorporate some of the benefits of LSLs. I'm thinking that warping is less of a concern for the top and bottom plates.

Is there any concerns with this approach?

In Building Code Questions | Asked By Rodrob15 | Feb 14 18
9 Answers

Fastening details - deck ledger to insulated slab

I am designing an insulated Monolithic Slab. I plan to install 4" of Roxul comfort board beneath and around the perimeter of the slab.

Does anyone have experience attaching a deck ledger to a slab (or stem wall) that is insulated with Roxul? Or is it advisable to place a higher density product beneath the ledger to avoid compression which may happen with the Roxul Comfortboard?

What type of fasteners are recommended for this application? Would a standard wedge type concrete fastener like a red head work?

Other solutions?

In Green building techniques | Asked By Michael Iacona | May 19 16
10 Answers

Heat pump water heater selection

My house is all electric in southern California and I plan to replace my electric water heater with a heat pump water heater. The plumbing professionals have little to no experience with these and are basically asking me to pick the water heater and they'll install it. From the research I've done it looks like the best choices include the Stiebel Eltron Accelera 300E and the Rheem Performance Platinum 80 gal. The Rheem is currenly on sale for $1600 at HD while the best price I saw for the Accelera is $2400. I believe my utility has a $250 rebate for the Rheem.

In Green products and materials | Asked By user-7014439 | Feb 11 18
31 Answers

Using hydronic in-floor heat in a superinsulated earth-bermed house

I'm planning an earth-bermed house at the 4,000 foot elevation in the mountains of eastern Washington. it will be single story, 8 foot 6" or 8" ICF walls on the sides and back. Back fill to 6" from the top of the wall.
The front will have a double 4" ICF front wall 2' tall and then double framed walls with thermal break to the top. This is south facing. front wall insulation is cellulose at about 18" thick but mostly windows 140 sq.ft on a 340 sq. ft. wall.
The floor will be 2" or 4" insulation with 4" concrete floor.

In Energy efficiency and durability | Asked By Grissom | Feb 13 18
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