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Message |
    
lisat
Citizen
Username: Lisat
Post Number: 134
Registered: 5-2001
| | Posted on Thursday, November 6, 2003 - 12:32 pm: |     |
Can anyone recommend a company to put insulation into an attic in an older home? Any recommendations as to the blown-in variety vs. the sheets of foil-backed insulation? Did it save lots of money in heating bills?
Any information is welcome. Thanks. |
tourne
Citizen
Username: Tourne
Post Number: 217
Registered: 1-2003
| | Posted on Thursday, November 6, 2003 - 3:46 pm: | |
The best thing that you can do in your attic is have air leaks sealed first (with a foam) and then have cellulose insulation blown in on top(at least a foot and a half deep). It's called "sealing the building envelope." The purpose is to prevent convective air flow into the attic where condensation can occur. It is the best thing that you can do to reduce your energy bills and increase the comfort of your house. Go to www.bpi.org to find a certified contractor. Note that you will have to look in NY to find one since there are none in NJ at this time. However, you can probably find uncertified contractors in our area to do the work. Adding any new insulation without sealing the building envelope first is a waste of money. As for insulation, loose fill cellulose is the best insulation--non-toxic, fire and pest resistant. The foam is sprayed in and does not contain formaldehyde. A trained contractor will do a blower door test first as well as check your furnace, stove and water heater for combustion safety if applicable.
I have seen some thin(low-e) insulation that is reflective and designed to be tacked to the rafters in the attic to reflect the incoming heat back out. Should make the attic cooler in the summer and help reflect heat back in in the winter. It is a 1/4 inch thick closed cell polyethylene foam with foil on both sides, kind of like a camping pad. I just bought some to insulate my garage doors. However, I have not heard much about how well it really works. See www.low-e.com. |
jgberkeley
Supporter
Username: Jgberkeley
Post Number: 3283
Registered: 5-2001
| | Posted on Thursday, November 6, 2003 - 3:56 pm: | |
Warning!
Installing foam to your attic rafters can cause early failure of your roofing material.
Attic rafters require the ability to vent air around them. Systems are made to allow that.
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tourne
Citizen
Username: Tourne
Post Number: 219
Registered: 1-2003
| | Posted on Thursday, November 6, 2003 - 9:08 pm: | |
jg,
The foam is used on the "floor" with insulation on top of it. ie. Pressure(air) barrier on the inside, thermal barrier on outside of the shell (living space). Depending on the outline of the "shell", it is a long standing misconception that venting is needed(though codes often require it). If no moist(warm) air is allowed to reach the rafters from the living space, then vents are really not needed and only serve to often allow moisture such as wind blown snow to enter the space. Yeah, this is some kind of roofing sacriledge, I know. The integrity of the shell is tested with a blower-door test. Otherwise, yes, moisture must be vented to reduce damage. Thing is, if the shell is leaking so much warm air from the living space to the attic, condensation will still cause damage regardless of venting.
jg, check out www.bpi.org and www.nesea.org for info and courses on building science and certification.
lisat,
Also check that there are no un-insulated ducts in your attic. If there are ducts, seal and insulate them. |
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