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Discussion Starter #1
Hello everyone,

Just purchased a 10 year old home which has a crawl space with no signs of insulation. Was / is this required?

At present, the attic is only accessed for maintenance / repair reasons and therefore the ceiling rather than the rafters are insulated. Year round temps are 20 to 105. Any benefit to insulating the rafters and or issues that would cause?

Thanks
BR
 

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You would only need insulation in the rafters if the attic was a living space. And it's normal to not have insulation in the floor over a crawlspace as the temperature down there doesn't vary very much.
 

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Discussion Starter #3
Thanks for the info...

We live in an area that can get snow and temps in the 20's is not unusual and can reach 110 in summer. With 6" walls I would have thought it would have better temp control, but we feel the drafts and the floor and floor area is really cold. We moved from a house in the general area, with 4 in walls on a slab. It controlled temps much better. What do you suggest?


Thanks for help,
BR
 

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Thanks for the info...

We live in an area that can get snow and temps in the 20's is not unusual and can reach 110 in summer. With 6" walls I would have thought it would have better temp control, but we feel the drafts and the floor and floor area is really cold. We moved from a house in the general area, with 4 in walls on a slab. It controlled temps much better. What do you suggest?


Thanks for help,
BR
Can't do a whole lot now. I wonder if the walls were sealed to the slab
and if there's housewrap installed.
 

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Can't do a whole lot now. I wonder if the walls were sealed to the slab
and if there's housewrap installed.
This place is about 10 years old and would guess it is wrapped. Most that I have seen built around here are. We are on a raised foundation / have a vented crawl space...no slab. Was comparing comfort level to our last place which was older on a slab.
 

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This place is about 10 years old and would guess it is wrapped. Most that I have seen built around here are. We are on a raised foundation / have a vented crawl space...no slab. Was comparing comfort level to our last place which was older on a slab.
Attic insulated well? Insulate the floor.
 

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Discussion Starter #7
Not sure what R value, but I think about 8 inches thick. need to check for areas that might have it moved or I suppose gaps.

I had thought about the floors... need to figure out the access. its tight.
 

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I'm confused by the answers. You are talking about an attic, correct?

If the HVAC and ducting is located up there, then insulate the rafters; http://www.buildingscience.com/documents/guides-and-manuals/irc-faqs/irc-faq-conditioned-attics?searchterm=attic+

If not, insulate the attic floor at least to code minimum. CA has it's own code- example, you may be in Zone 3, 4, 5, or 6; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec001_par001.htm

Then compare the requirements for you walls, floor, and roof; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec002.htm

Air seal the holes in the crawl space (under the house) to floor above (this should have been done 10 years ago- along with the insulation), then the attic holes to stop the stack effect; http://www.wag-aic.org/1999/WAG_99_baker.pdf

http://www.google.com/url?sa=t&source=web&cd=23&ved=0CCUQFjACOBQ&url=http%3A%2F%2Fapps1.eere.energy.gov%2Fbuildings%2Fpublications%2Fpdfs%2Fbuilding_america%2Fba_airsealing_report.pdf&rct=j&q=foam%20board%20in%20attic%20require%20thermal%20barrier%20with%20drywall%20already%20installed%20on%20other%20side%20of%20kneewall&ei=IvqWTveuIKW0sQK3zPzwBA&usg=AFQjCNHwd56o0AxLi8-V03E5cMUmwWATQw&cad=rja

Air seal the rim joists; http://www.buildingscience.com/documents/information-sheets/critical-seal-spray-foam-at-rim-joist/

Describe the house/attic……

Gary
 

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Discussion Starter #10
Hi Gary,

The 10 year old home is single story with 6 inch walls a 6/12 roof pitch and is located in a 4b zone of Ca. We get into the 20's in winter and maybe some days of 100 to 105 in summer. It has a raised foundation.

It has a non conditioned attic space (access for mechanical reasons) which has all duct work related to the hvac in it. The floor of the attic space (ceiling joists is insulated with what I think is about 8" to 10" thick fiberglass. The rafters have no insulation. I do not think we will be doing anything with the space up here, very slim chance we might use a small portion for storage.

The crawl space has no insulation of any kind, the floor is plywood and depending on the roof, has either tile, wood or carpet.

We notice that temperatures do not feel as constant / comfortable without heat or a/c when compared to our last place which is about 4 miles away. It is about 18 years old, had 4" walls, a package HVAC on the roof on a slab and about 1500 feet lower.

1. The floors are cold and we feel the cool air down low.
2. The return air on the hvac (split unit heater/blower in garage - coil on pad outside) dumps cold air out when not running and when it first fires up. blows cold air for a min or so.

I would like to deal with both issues.

Thanks
BR

I'm confused by the answers. You are talking about an attic, correct?

If the HVAC and ducting is located up there, then insulate the rafters; http://www.buildingscience.com/documents/guides-and-manuals/irc-faqs/irc-faq-conditioned-attics?searchterm=attic+

If not, insulate the attic floor at least to code minimum. CA has it's own code- example, you may be in Zone 3, 4, 5, or 6; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec001_par001.htm

Then compare the requirements for you walls, floor, and roof; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec002.htm

Air seal the holes in the crawl space (under the house) to floor above (this should have been done 10 years ago- along with the insulation), then the attic holes to stop the stack effect; http://www.wag-aic.org/1999/WAG_99_baker.pdf

http://www.google.com/url?sa=t&source=web&cd=23&ved=0CCUQFjACOBQ&url=http%3A%2F%2Fapps1.eere.energy.gov%2Fbuildings%2Fpublications%2Fpdfs%2Fbuilding_america%2Fba_airsealing_report.pdf&rct=j&q=foam%20board%20in%20attic%20require%20thermal%20barrier%20with%20drywall%20already%20installed%20on%20other%20side%20of%20kneewall&ei=IvqWTveuIKW0sQK3zPzwBA&usg=AFQjCNHwd56o0AxLi8-V03E5cMUmwWATQw&cad=rja

Air seal the rim joists; http://www.buildingscience.com/documents/information-sheets/critical-seal-spray-foam-at-rim-joist/

Describe the house/attic……

Gary
 

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Air seal the duct work with heavy duty foil tape/mastic, decide if a conditioned attic is beneficial or not, post in "HVAC" on the furnace problems, blow cellulose (help stop air leaks) in the walls/attic after all I said earlier, insulate the crawl floor/walls- your choice; http://www.buildingscience.com/documents/reports/rr-0401-conditioned-crawl-space-construction-performance-and-codes

http://www.buildingscience.com/documents/information-sheets/crawlspace-insulation/

With no insulation/little in attic, walls ?, and floors, I'm guessing there is no plastic v.b. on the dirt down there?http://dirt-crawl-spaces.com/crawlspace-dirt.html

Gary
 
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