I'm looking to reinsulate my finished attic to get the best R value possible. It's a cathedral ceiling on the top floor, and while it's usually comfortable in winter, it gets really hot in the summer. In Eastern PA, the recommended R value is 31 for ceilings, so I'm leaning towards a higher value. I have six inches of depth and can choose between fiberglass insulation rated R21 for $1100 or rockwool rated R23 for $2100. I'm on a tight budget and wondering if spending the extra cash for rockwool is really worth it for the slightly higher R value. This is my first big home improvement project, and I'm a bit overwhelmed with the decision. Any advice would be appreciated!
3 Answers
With such a small difference in R value, it might not be worth the extra cost for rockwool. You could save that cash and invest it into air sealing, which can make a bigger difference in energy efficiency. Also, check if you can add insulation beyond the joists with furring strips; it might be more efficient that way. Just something to think about!
If soundproofing is a concern, then rockwool is worth it for your project. But if noise isn’t an issue for you, then sticking with fiberglass should do the trick!
Before making a decision, see if you can qualify for any local rebates or incentives for insulation. Some programs might cover half the costs, which would help a lot. I personally prefer rockwool because it’s easier to handle and has great moisture resistance, not to mention it performs well in terms of insulation.
Good point! Rebates can make a big difference in these projects. I completely agree on the handling of rockwool; it's definitely easier to work with than fiberglass.
Thanks for clarifying! I was just unsure about how much depth you had. Furring strips could definitely help maximize your insulation, plus blown insulation might be an option for you.