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12 Answers

Choosing and balancing R-values

We are in Minnesota (Zone 6a). The home is an "L" shaped, 2200 sq/ft single level, slab on grade with a 28'x40' attached garage making the "L"

I'm looking to nail down the R-values of the wall, ceiling and slab. If we do a 10" double stud wall with dense pack cellulose (R30) and 4" of EPS (R20) for the FPSF...what should we aim for in the ceiling? Is there a formula or rule of thumb to follow to balance these?

We are thinking 8/12 pitch gable roof, 1' energy heel, and scissor trusses (3/12 interior pitch) over the 26 x 34 living room/kitchen/dining room area.

In Energy efficiency and durability | Asked By Scott K | Apr 20 17
4 Answers

Question on vapor retarder on interior dividing wall

First off, thanks to the many that respond to questions posted by us less experienced folks! I have learned a great deal from this site so thank you.

In General questions | Asked By James Culbertson | Apr 21 17
8 Answers

Heat build up in Florida garage

I friend of mine in Florida, zone 2A is trying to reduce the heat build up in his attached garage. He has a tiled, hip roof. I think he has soffit vents but no roof venting. There is a decorative half moon in a small gable above the garage door that maybe could be used as a gable vent.

He is looking at insulating either the garage ceiling or roof. He also mentioned a radiant barrier.

Being from the north, I suggested venting to let the heat our rather than insulation. What do you think would be the most cost effective and efficient way to help keep the garage cooler?

In General questions | Asked By jim sweazey | Apr 20 17
7 Answers

2/3 1/3 insulation rule in roof

Old build with flat wood deck on 2x13s. 4 inches Batt in joist space.(R12) 2 inch air space above batt insulation under wood deck No external vents into air space Adding polyiso on top of deck R 28. Before adding the polyiso can/should we put a separator sheet or vapour barrier on top of the wood as there is more than 2/3 the insulating value above the deck There is a poly vb above the drywall ceiling below e joists.

In GBA Pro help | Asked By UBSC | Apr 19 17
27 Answers

ERV selection

I've been reading, reading and reading about the various ERV options. Once I think I've narrowed it down, I read a new article or a new model has be released. What is the latest thoughts on the ERV market ranking them from best and also value?

In Mechanicals | Asked By Seth Holmen | Mar 26 17
4 Answers

One more question about rainscreens

When using a 3D rainscreen material like House Slicker, Delta-Dry Stucco & Stone, or Sure Cavity behind stucco, you need something between the stucco and the rainscreen material to keep the stucco from clogging the channels for drainage and air. Some of these materials come with a pre-bonded fabric to do this, whereas you would otherwise put something like a layer of felt on top of the rainscreen and behind the lath and stucco.

In Green building techniques | Asked By Domenico Perrella | Apr 20 17
1 Answer

Which wood material (siding material) for shed?

The two shed sellers near my place has Duratemp and LP Smartside, is one better than the other in terms of durability?

In General questions | Asked By Joe Blanco | Apr 20 17
4 Answers

Dual Stage vs Single Stage Heat Pump

Hello all:

In Mechanicals | Asked By Adam S | Apr 20 17
2 Answers

Drywall Dust & HVAC Return


I am replacing old wooden wall paneling with drywall.

One of my furnace air return vents is on a wall I am drywalling. The sheetmetal return ducting is flush with the framing, not extended out - when I drywall around it, the metal ducting will be 1/2 inch removed from the grill/register.

My question: what should I do to avoid dust from the cut edges of drywall getting sucked in to system? i.e. all the air coming into this return first passes the cut edge.

Few ideas:
1. extend the ducting 1/2 inch out from the framing so it is flush with the drywall paper face

In Mechanicals | Asked By Matt Draper | Apr 20 17
3 Answers

Insulation for a DIY air cooling pot

we are building an air cooling pot from a food grade 1gal plastic bucket and need to LINE THE BUCKET with an insulator. Syrafoam is used in most cases but we would like to avoid it if there is something else available. It should be water poof as ice will melt inside the bucket. Need to be able to cut to fit easily and be very lightweight. oh--and cheap! because we're cheap. :)

Thank you very kindly!

In Green products and materials | Asked By Skadeetin | Apr 19 17
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