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17 Answers

Skipping radiant floor heat in a passive house?

I'm building a house with (conservative numbers) R 60 walls and R90 ceiling. The windows are in-swing casements with double seals. The floor is going to be stained concrete on 2" insulation. I had 2 consultants tell me that I will not need radiant floor heat it will be too much. We will have a whole house air circulation system and a gas fire place. I am worried about not putting in the pipes in the floor and then being wrong. I am considering just putting in the heated floor under the rooms away from the fire place. I could add a heater to my whole house ventilation system if needed.

Asked By Jenz Yoder | Aug 25 15
5 Answers

Insulate cold water pipes

Replaced galvanized pipes wth copper about 15 years ago.
Current hot weather in California causes extreme heat in attic despite solar attic fan and gable vents.
Cold water in pipe line is extremely warm and warm water is now in toilets
Fear warm water may crack toilet tanks and ruin flooring.
How best to insulate these cold water pipes from water getting warm?
Company which did insulation spoke of 3" wall around these pipes.
Can you explain what this is and best way to insulate these pipes?
Thank
Paul

Asked By Paul Deleon | Aug 28 15
3 Answers

Unvented Roof, 3B, Foam-Free

Hi Martin,

First off, I have read a wealth of articles on the subject of unvented roofs, by yourself and Joseph Lstiburek. I started with your “How to Build A Cathedral Ceiling” article and read pretty much everything related to this from you and Lstiburek. The conclusion being that for an unvented roof you either install closed-cell spray foam between the rafters, or rigid foam above the sheathing at a thickness dictated by your climate zone to keep the sheathing warm enough.

Asked By Joe G | Aug 26 15
9 Answers

Does an 850-square-foot house have to have return air ducts?

I live on a slab one story home. I currently have an old forced air gas furnace that I would like to get replaced as well as install central air conditioning. I had a local contractor come out and quote a complete system and was told I would need all new ducts because I didn't have a return air system. The furnace currently is in a central closet with a large air grate on the side letting air back to the furnace. It is right in the middle of the house and I usually leave all doors to all bedrooms open. He quoted me $12000 for the whole job.

Asked By Brett Obraza | Aug 27 15
1 Answer

Methods for air sealing the ceiling

Hello,

We are building in a cold climate, zone 7, using ICF walls. Because the walls are ICF, they act as an air barrier, but I'm trying to figure out the best way to air seal the ceiling. Based on what I've read on this site, I'm following a few guidelines:

  • Ceiling will be flat, using energy heel trusses
  • Using blown in cellulose, thinking around R-60
  • No recessed lighting (thanks Martin)
Asked By Nick Hall | Aug 28 15
5 Answers

Minisplit or furnace?

Hi, I know there is lots of discussion about this; however, our proposed new construction seems to be in unclear realm of which to use.

Asked By Mark Buckingham | Aug 28 15
44 Answers

Re-roof and insulation question

I have a 22 year old home. It has a 25 year comp roof on it with 1/4" Foamcore insulation under it. I need to re-roof and wanted more insulation (thinking about 3/4" foam). Can I just run a 1" x 4" around the edge and put new drip edge and sheet over the old roofing with the foam and putt the new reflective comp roof over it? If so, what kind of foam do you recommend? Really appreciate your input. Thanks.

Asked By Ted Salyer | Aug 26 15
2 Answers

Extra furring strips into OSB only

I was recently snooping around a house under construction by Habitat for Humanity in Traverse City Michigan. The house is frame 24" o.c. and has two layers of 2" XPS foam (4" total) over the OSB sheathing. In addition to furring strips over each stud, they have attached furring strips between each stud such that there is a furring strip every 12". As far as I could tell, the only thing these additional furring strips could attach to is the OSB. Does this make sense?

Asked By Reid Baldwin | Aug 28 15
5 Answers

Do I need to follow the insulation code in any circumstance?

I am converting the sun room to bedroom.
The room is isolated from main building and faced with garage. Only 200sqft room.. no bathroom will be installed in the room.

The room have nothing but the roof above.

Asked By mansig yoon | Aug 26 15
7 Answers

Include provision for future ventilation?

The second story of my old farmhouse is gutted. I am in the middle of running electrical, etc and getting ready to close up the walls. It doesn't need it now, but as I keep working, the house may eventually need a ventilation system. Should I include provisions now while the walls are open for a ducted ventilation system later? Is separate ventilation ducting overkill? What type/size of ducting is typically used for the application? Is it best to locate grilles in the floor or walls?

I have done a lot of reading on the topic but I would like some input others.

Asked By Brian C | Aug 21 15
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