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Discussion Starter #1
Hello,

I have a ranch house with one additional room that was added on off the back roof of the house. I am replacing the ceiling which is just basic 12x12 ceiling tiles.

My question is regarding the insulation that is present. Currently they used - Owens Corning fiberglass insulation(if I take it down Ill get it checked for asbestos first as it seems owens corning used asbestos back in the day)
Its in kinda bad shape.. its ripped and most of it is a dark brown and not the Pink anymore.

I want to replace it but not sure what is a good insulation for this area. This insulation is basically in between the rafters butted right up against the roof.

Is the normal pink roll type insulation all I need to do it correctly? Any suggestions would be appreciated.

Thanks

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Exterior Construction
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1. Highly unlikely that has asbestos. It was long since out before FSK (foiled faced insulation) of that generation was out. You should still use proper PPE if you are going to take it down.



2. Is the roof vented currently?



3. Are there issues in the room (temperature wise)? If not, why remove the insulation?
 

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We need to know your climate region to advise about condensation issues.
The current ceiling is not air tight so conditioned air has been filtering up into the rafters.
As for current insulation being up against the bottom of the roof, not good, but climate related.
Is there an attic above the middle portion of that ceiling? Have you been up there?

Bud
 

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Discussion Starter #4
Thanks for both of your responses.

Responding to Windows on Wash:

- The roof is vented as there is a vent at the peak of the roof and then under the overhang(eaves??) outside there are vent holes.

- So this is an addition and there are duct vents but almost no air comes out of them when the heat or ac is on. In the winter its not to bad worst case we use an electric heater.. But in the summer its basically unusable unless we run a window AC unit for a long while in there to cool it down.

- When I took down the ceiling tiles there were a lot of mouse droppings.. Now my wife is like pull it all down as she is grossed out. We have been in the house for 2 years but it was vacant for a good 6-8 months before we bought it.

Responding to Bud9051:

- I am in the Camden New Jersey area.

- We have an attic but this is an addition and that peak above this room there is no access to that part.
---- Actually I just took a stick and ran it up the side of the insulation at the flat part and its all wide open above the insulation where its flat. So if I take the insulation down I have access haha. Why do you ask about the access?

So im not sure yet if Im replacing all of the insulation..or just some or any yet.

But what would be proper method? and suggested insulation to use?

Thanks!
 

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retired framer
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Are the rafters 2x6 or? how thick is the insulation? If mice could get in and under the insulation then so could outside air, so the insulation was not doing anything.
 

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Discussion Starter #6
The ones on an angle are 2x6 then the ones going straight across at the top are 2x4. The insulation looks to be about 4 inch thick
 

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retired framer
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Normally we lower the sloped ceiling another 2x4 which would allow 8" of insulation.
 

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Discussion Starter #8
Thanks everyone for the responses.

What would be the suggested insulation to use here? Im near the camdon NJ area.

Thanks
 

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Seems that in NJ, current code for a new house is R49. That would be a good target for your remodel.
https://www.efficientwindows.org/codes2015/NewJersey2015.pdf
If you don't already have chutes over your soffit vents, put some in to make sure you don't block the ventilation.

Seems you will be installing the insulation from below, so that is going to dictate your insulation choice. Never tried installing insulation from below, myself.
I don't see how blown in cellulose or fiberglass would be practical.
I expect you could put one layer of batts above the ceiling joists, and then stuff another layer of batts between the ceiling joists. Fiberlass or rockwool batts are readily available. Rockwool is more dense and rigid, and that might be an advantage when you stuff insulation between the ceiling joists.
 

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Discussion Starter #10
ah perfect thanks.

What do you mean "chutes over your soffit vents"? is that for venting?

I got it. So I can lay batts across the ceiling then stuff batts between the ceiling joists? Never throught of that. Thanks!
 

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The insulation is discolored due to air movement.

It's more important to stop the air movement than have high r-value.

The first R-10 does most of it.

I wouldn't worry about trying to get to R50 - it's not practical and the energy savings aren't great.

If you;re set on bats, use R-24 roxul in the 2x6 sections and R-14 roxul in the 2x4 sections.

You'll need a vapour barrier on the warm side when using batts.

Because no vapour barrier is perfect and roofs don't have drying potential, you'll need baffles under the roof so there's a clear ventilation path between roof vents near the peak and soffit vents. (in absence in soffit vents, have roof vents added away from peak)

You'll have to use thin baffles or the batts won't fit properly.

The alternative is to use spray foam.
 

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with so little available thickness for insulation, I think this would be a perfect job for foam over the cardboard vents. Did a similar innsulation on my roof with great results
 

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Spray foam is indeed the best insulation for this application, but is expensive and toxic.
 

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Discussion Starter #16
Thanks.. couple more questions then I think Im good.

1 - Since this room is an addition. The right side is to the outside but the left side slopes down and into the attic where it meets the original ridge board. There is no vents as its basically a closet then the rest of the attic. My question is.. Should I still put the vent baffles in and maybe poke a few holes in the drywall on the other side of this wall/ceiling to allow attic airflow up the roof? or no? Not sure if that makes any sense.

2 - when connecting two batts together.. when they meet if you need a long piece.. Do I tape the vapor paper together to hold them? or staple them together? or just butt them up to each other? if tape what kind of tape?

Thanks again for all the ino
 

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Yes, you should still have venting, even if part of the attic is blocked.

Around here, a vapor barrier is a 6 mil sheet of plastic on the "warm in winter" side. Things may be done differently in your area.
 

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Discussion Starter #18
Got it Thanks Ill add the baffles on that side too.

The distance is 22 inches from the tiles to the bottom of the ridge board. why do you ask?

What about butting the baffles up together.. should I staple, tape or just butt them up to each other?

Thanks
 

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Discussion Starter #19
-- correcting my last post --

1 - Got it Thanks Ill add the venting to that side too.

2 - The distance is 22 inches from the tiles to the bottom of the ridge board.

What about butting the insulation together? If I need to connect two batts together for a long run should I staple, tape or just butt them up to each other?

Thank again
 
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