batt vs spray foam for a 2x6 attic

[ginmul333]

I'm trying to help my aunt with an attic remodel, and I'm a little stuck on the best way to insulate it. We're turning her attic into a usable space, but the rafters are only 2x6s.
I was looking into spray foam, but the company told me we might have to add more wood to get a good R value, which sounds like a lot of extra work. Would bat insulation be a better option?

We're also putting in a knee wall, and she wants to use the space behind it for storage. I know we need to insulate the access door, but I'm wondering if anyone has a better suggestion than just buying a premade one online?

Any advice would be a huge help! Thanks

 

[Harrity]

With 2x6 rafters you'll be tight on R value either way and spray foam gives you more in less space, but it's ore expensive. If you go batts, you may need to add furring strips for depth

 

[Port Molyneux]

We finished my neighbor's attic last fall and ran into the same issue with 2x6 rafters. Closed-cell spray foam worked out since it gave us the insulation we needed without adding extra wood. For the access door, we just made one from plywood, stuck some rigid foam on the back, and sealed it with weatherstripping. It did the job and saved a few bucks. Will the space be used full-time or just now and then?

 

[CircuitGeek]

I'm trying to help my aunt with an attic remodel, and I'm a little stuck on the best way to insulate it. We're turning her attic into a usable space, but the rafters are only 2x6s.
I was looking into spray foam, but the company told me we might have to add more wood to get a good R value, which sounds like a lot of extra work. Would bat insulation be a better option?

We're also putting in a knee wall, and she wants to use the space behind it for storage. I know we need to insulate the access door, but I'm wondering if anyone has a better suggestion than just buying a premade one online?

Any advice would be a huge help! Thanks

yep, @Harrity is right. Rvalue is your main enemy here. Spray foam is the gold standard for maximizing Rvalue in shallow spaces and dealing with air sealing, but it is expensive. If you can afford it, it’s the superior solution for making the space truly comfortable

 

[cordur0y]

For the knee wall, insulate it well and seal it tight, foam board with taped seams works nicely