Help me beat the heat (in my attic)!
July 3, 2012 2:02 PM Subscribe
Calling all home improvement gurus and energy efficiency wizards--help me figure out how to better insulate my attic! I've read through a bunch of information on energystar.gov and other websites about insulating attics, but the more I read the more confused I get about how to do this, because I have the world's weirdest attic. HELP.
posted by iminurmefi to home & garden (12 answers total) 5 users marked this as a favorite
So, we recently purchased a lovely small brick house in Colorado with no A/C. For the past few weeks, I've been dying of heat inside nearly every day--which was quite surprising, as the rental I used to live in down the street (same size, but made out of river stone rather than brick) had no A/C but remained a lovely 70 to 75 degrees no matter how hot it was outside. I suspect the issue is heat leaking down from that attic, and I'm desperate to fix it.
The primary air leak appears to be through an enormous and not-well-sealed set of attic stairs. The stairs were built by a previous owner, and use a rope-pulley system to allow someone to basically pull down 10 feet (yes, you read that right) of the house ceiling/attic floor into the main space of the house. The pulley system plus the size of the hole in the ceiling for the damn stairs (3 feet wide by 10 feet long!) means it's not going to be possible to just add on an attic tent or build a box to seal off the air flow, which was my original plan. So, I'm thinking we need to add insulation to keep the attic itself cooler, because then at least the air leaking into the house wouldn't be SO DAMN HOT.
However, all the information I'm able to find online about adding insulation assumes that the CURRENT insulation is tucked in along the floor joists of the attic, and suggests just laying more on top. (Oh, how I wish it was that easy!) In our house, the joists are actually covered by wood making a flat, regular-looking floor, and the R-19 insulation is tucked up along the attic ceiling between the rafters and along the attic walls. Not around the whole attic, mind you, just in a 20 foot by 10 foot area centered around the attic stairs. So, my questions are:
1. Am I right in thinking that the best way to accomplish my ends is to insulate along the attic ceiling rather than along the attic floor, given that it doesn't appear we can totally stop the air flow from the attic space into the house? Or would there be some benefit to spreading insulated batting all over the floor, except for the gaping 30 square foot hole that is the attic stairs?
2. How in the world do we add more insulation to the attic ceiling, when it doesn't look like there is any room to tuck more insulation between the rafters? (The rafters aren't that deep.) Should we rip out the R-19 that is in there and replace it with something bigger?
3. Is the current set-up of an "insulated room constructed from R-19 batting inside the attic" (that is, insulation doesn't run all the way to the outside edges of the attic) going to cause us problems in the winter, or is it okay assuming the only real air leakage we have (that I know of) is inside that little insulated room?
4. One idea I had was to install radiant barrier loosely hanging off the rafters, which should at least cut down some on the heat radiating down from the asphalt shingle roof into the attic (and subsequently from the attic into the house). I think this should help with the heat in the summer, but probably won't do anything to help heat from leaking out into the attic in the winter. Is there a better solution, or is this the best I can do?
Sorry for the long question--there's a ton of great information about insulating attics on the internet, but none of it appears to address the total weird factors in play in my attic. I'm hoping some mefite with more handyman/DIY experience might have some good ideas for me.