My one story ranch has three different types of insulation. Should I start over?
I bought a house that has an extremely hot attic. There is insulation all over the place. Batts, two different blown in, and sections of bats just thrown around not even laid straight.
Inspector said soffits were covered. I know I need to get insulation off the soffits, but I’m wondering if I should start over with a uniform type and thickness of insulation. Attic vents? Supposedly there are ridge vents installed.
The air conditioner seems to work hard even though it’s only a year old. What’s my optimal plan? There are no ducts in the attic. One section (my single rectangular ranch has three different roof heights in a row) has been vaulted and has a tiny attic at one end.
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Yes, it would probably be a good idea to start over, especially if you are doing the work yourself.
Ideally, you would
1. Remove the existing insulation, perhaps in sections
2. Air seal like crazy - air seal the ceiling j boxes, any duct boots, ceiling exhaust fans, the top plate at the perimeter, any top plate holes for wire or pipes, any can lights, etc. Do alot of research on air sealing.
3. install soffit baffles
4. insulate - you can blow in cellulose
Messy batts are probably not laid correctly, and not doing as much as they could if placed properly. Having a mix of different insulating materials isn't really a problem though, as long as they were all installed correctly. It's common, for example, to blow in additional loose fill insulation over an older layer, or over a layer of batts, to up the total R value of the assembly. This is standard practice, and not a problem.
Attics always tend to run pretty hot on sunny summer days. Check your vents though, you should have BOTH soffit AND ridge vents. It's easy to see if you have a ridge vent, since you can see it from ground level. There are some kinds (like the "shingle over foam" style) that don't really work all that well though. If you have blocked soffit vents, that's probably a big part of the problem. The vents need to work together as a system, with the soffit vents allowing air in, and the ridge vents allowing air out. Together, you get convective aiflow, which is MOVING air ventilating the attic. That's why having ONLY soffit vents doesn't help all that much.
I would fix the vents first, see if that makes a big difference. You could probably improve things further by air sealing the attic floor, which is best done after removing all of the existing insulation to allow you to get to the things needing to be air sealed. If you end up removing the old insulation and air sealing, put in a uniform layer of blown cellulose to get up to at at least code minimum R value for your climate zone (most zones are R49 minimum now), and be sure to put some vent baffles out at the eaves to keep the soffit vents clear. Also be sure the new insulation covers the top plates of the exterior perimeter walls.
Bill
The different types of insulation sounds a bit like my attic. Whenever there is leftover insulation on a job it comes home with me instead of getting tossed into the dumpster. I just put it up in the attic on top of settled cellulose and other random batts. It's all just bonus R value!
Once the attic is air sealed from the house and the venting is clear, then the goal is to just have as much insulation as you can afford, and since it's already there, then why get rid of it? Fashion? Nobody else is going to see it.
I see no need to remove insulation and send it to the landfill. Maybe move it around to make it more even, but why waste what you already have?