Buying my first house - a perfectly little music bungalow

1964 · Post by **1964** » Wed Sep 23, 2015 9:38 am

Looks awesome! Congrats!

Flight Feathers · Post by **Flight Feathers** » Fri Sep 25, 2015 7:21 am

If it is not too late (and even if it is), I would strongly suggest looking into spray foaming the attic, at least the roof in between the rafters, but also the walls if you can. I live in a similar climate - North Jersey, and got our attic spray foamed, and man is it a difference maker. The thermal impact is huge. Our house is always the last on the block with snow still on the roof, meaning the heat is NOT going up and out through the roof. And the acoustic impact is also significant, you will be sealing up all the tiny gaps in the outer shell, making for a much more soundproof assembly. I don't know what kind of noise you plan on making up there, but it will make a difference in containing it.

norton · Post by **norton** » Fri Sep 25, 2015 3:13 pm

I'm with you on the thermal flight feathers!

Spray foam is VERY impressive thermally. Not just temp wise...but humidity as well.

I've got an addition I'm finishing now that's been foamed. It's amazingly efficient! And super cost effective in the long run. Both on energy use and comfort.

It does create a perfect envelope, with no gaps, but it's not as effective as fluffy insulation try's as far as sound transmission goes.

Styrofoam boards have near zero effect on sound transmission. Spray foam sure seems to be a far better than rigid foam boards. I haven't seen any test results on stc performance of current foam formulas. I wonder?

alexdingley · Post by **alexdingley** » Wed Oct 14, 2015 7:30 pm

Thanks for the insights... I would have loved to do the Spray Foam, but I wasn't ready to put in the extra cash. ... mostly because I came to find that the house is gonna need some fairly significant structural fixes in the next decade... Nothing major right away, but chances are I'm gonna end up ripping some parts of the house down to the studs, one day, and then doing a major renovation to this part of the house... So I figured I'd do v1 on the cheaper side... and in a couple years, I'll probably expand & redo the upstairs. At that point, I'll probably go with the spray foam.

All my reading / youtube research definitely agreed with you too, Flight Feathers.

alexdingley · Post by **alexdingley** » Fri Oct 23, 2015 10:57 am

So... I've made a change to the plan... we're adding the spray foam to the attic roof. contracting with a local company today ??they should be spraying a couple inches of foam into my attic bays. Thankfully, we hadn't finished the top walls yet... so I ca pull-out the mineral wool / let them spray behind the wool & put back the bats. It should easily double my R-value & protect against any possible condensation problems in the future.

It's definitely expensive, relative to the mineral wool (3x more) but it truly seems like it's the right thing to do in here. As the weather gets colder, this fall, I'm already noticing how cold it gets in this house.... so this will be a huge help.

norton · Post by **norton** » Sat Oct 24, 2015 9:40 am

You'll be happy you did this!

I've been amazed at how well the foam insulation does in hot humid weather, keeping the humidity under control. Money well spent!

Flight Feathers · Post by **Flight Feathers** » Tue Oct 27, 2015 6:31 am

alexdingley wrote:So... I've made a change to the plan... we're adding the spray foam to the attic roof. contracting with a local company today ??they should be spraying a couple inches of foam into my attic bays. Thankfully, we hadn't finished the top walls yet... so I ca pull-out the mineral wool / let them spray behind the wool & put back the bats. It should easily double my R-value & protect against any possible condensation problems in the future.

It's definitely expensive, relative to the mineral wool (3x more) but it truly seems like it's the right thing to do in here. As the weather gets colder, this fall, I'm already noticing how cold it gets in this house.... so this will be a huge help.

I think you'll more than double your R-value, more to tune of 20 to 30 times improvement. Looking at your original picture, it looked like your attic was just the roof assembly - rafters, sheathing, shingles. That doesn't have any thermal value, basically R1. Go up there on a cold morning like today, I bet it is pretty close to the outside temp in there. Closed cell spray foam is R6.5 per inch, put in 5 inches, you are at R30. Huge difference.

Let me ask this, what is the purpose of the mineral wool batts? They have no thermal properties, only acoustic. Are you trying to make a dead space? Do you have any soundproofing needs, or just acoustic treatment?

norton · Post by **norton** » Thu Oct 29, 2015 6:46 am

Mineral wool has a r value very similar to fiberglass....

Closed cell foam has other benefits than just thermal. It forms a perfect vapor barrier so no drafts or leaks, and is excellent at keeping the summer humidity outside as well. Good stuff!

alexdingley · Post by **alexdingley** » Thu Nov 05, 2015 9:27 am

accidental double-post

alexdingley · Post by **alexdingley** » Thu Nov 05, 2015 9:28 am

Just took down the mineral wool & have spray foam guys coming today...

whew!

alexdingley · Post by **alexdingley** » Thu Nov 05, 2015 4:36 pm

Flight Feathers wrote:If it is not too late (and even if it is), I would strongly suggest looking into spray foaming the attic, at least the roof in between the rafters, but also the walls if you can. I live in a similar climate - North Jersey, and got our attic spray foamed, and man is it a difference maker. The thermal impact is huge. Our house is always the last on the block with snow still on the roof, meaning the heat is NOT going up and out through the roof. And the acoustic impact is also significant, you will be sealing up all the tiny gaps in the outer shell, making for a much more soundproof assembly. I don't know what kind of noise you plan on making up there, but it will make a difference in containing it.

So... I got a couple inches of closed-cell spray foam sprayed into the ceiling attic bays. I'll be putting the mineral wool back tonight. Check it out!

norton · Post by **norton** » Fri Nov 06, 2015 6:53 am

Did they get behind your knee walls as well?

Mmmm stinky yellow foam!

alexdingley · Post by **alexdingley** » Fri Nov 06, 2015 7:21 pm

No, they didn't go behind the knee walls... but I will be able to do that at a later date if I need to. I've got mineral wool behind the knee walls now.. and if this winter is too brutal, I'll seal it up in the spring.

norton · Post by **norton** » Sun Nov 08, 2015 6:58 am

hope it works like a charm!

alexdingley · Post by **alexdingley** » Fri Nov 13, 2015 5:56 am

norton wrote:hope it works like a charm!

Yeah, I'm hoping so too... The bare construction offered plenty of isolation, so I think my sonic-isolation will be pretty stellar... but now I'm expecting that the room will be far more comfortable to spend long times in... without costing me an arm/leg to heat.

The top dry-wall is going up:

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Buying my first house - a perfectly little music bungalow

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