Insulation Dilema- Vaulted/Cath. Ceiling

JLOC

i am hoping to get some feedback on the issue I have found in my house while redoing our dining room. The electrical issues that can be seen in the photo's are one of the reasons I pulled the drywall to begin with and are being corrected. My dilemma at the moment is how to properly insulate this area of the house.

The roof/ceiling is 2x4 construction and pretty much "Non Vented" (to the outside of the house anyway). Whoever re drywalled this room at sometime before I owned the house installed FG insulation in some places and none in others. It was poorly done. The drywall is chalky and feels dried out. I am going to pull the rest down and redo it all but my dilemma lies in how to insulate this area the right way.

In this photo it shows the lower side of the room. The wall joins the dining room and our garage... Sooo obviously not vents here.

http://craftwerks.smugmug.com/Other/.../IMG1221-M.jpg

In this photo, It shows the higher side which shares the wall with out kitchen. There is no blocking and it is open to our attic space.

http://craftwerks.smugmug.com/Other/.../IMG1220-M.jpg

Here is an overall shot of the ceiling.

http://craftwerks.smugmug.com/Other/.../IMG1222-M.jpg

Here is the adjacent room that is also vaulted. This has been poorly insulated as well (from the inside and covered with bead board) and is going to get redone. This room has 4x6 beams, T&G for the ceiling.

http://craftwerks.smugmug.com/Other/.../IMG1223-M.jpg

My plans are to have it insulated from the outside when we redo our roof so that we can leave the beams and T&G exposed.

I am in Southern California FYI.


Any input would be much appreciated!

Thanks in advance!

gregzoll

Can you post a outside shot from roof level, then one from the ground also, so that people can get an idea of what the roofline looks like. If it was me, and I was going to do it correctly, I would be going with spray foam on the roof.

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JLOC

Will try and get a few pics showing the ext. in a bit.

Thanks.

JLOC

Here is a shot of the roofline.

The lower level to the left is the garage.


http://craftwerks.smugmug.com/Other/.../M/Image-M.jpg

gregzoll

Standard roofline, I would treat it as that. If it was vaulted, then yes insulate outside, but in this case, insulate the bottom side, maybe reflective foamboard with the foil facing the sheathing.

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JLOC

Thanks for the reply....

Will I not have to worry about any condensation build up as it is a non vented area of the roof?

Should I go as thick as possible on the foamboard or no?

gregzoll

I would still vent the space. When spray foam is used, or the reflective foam board is used, it then creates a thermal break.

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JLOC

Venting isn't much of a possibility.... As I mentioned above, The lower side of the room shares a wall with the garage so there is no way to have incoming air from the outside. The high side I could leave open to the attic but no way to vent to exterior.

Windows on Wash

You can probably drill some cross over holes in the rafters (as long as they don't weaken the structure) to get some air over to those rafter bays.

You could also rip some kirf cuts in the foam if you are going to apply that over the rafters to allow some cross over ventilation.

What is the garage like? Attic or vaulted?

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JLOC

The garage does not have an attic space. It is exposed 2x4 framing like this room except it is not insulated or drywalled.

Windows on Wash

Vent that section of the garage where it connects via the eaves and close off those few rafter bays with drywall to prevent it pulling air from the garage.

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JLOC

Thanks, I will look into that... That very well might be an option.

Any any ideas, thoughts on leaving it closed and spraying foam?

Windows on Wash

I would probably go with greg's recommendation of rigid foam with a foil facer and vent the roof.

You are not too worried about heat loss of there and thermally breaking the roof assembly would go along way to helping with the cooling and heating load.

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Gary in WA

Where are you located in S.Cal.? There are 3 zones there; http://publicecodes.citation.com/ico...001_par001.htm

No foil-faced foam board on the rafter bottoms in your location, especially if you run AC, the rafters will rot without ventilation.

Gary

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JLOC

Gary,
I am in 3B. (los angeles) was the closest they listed.