Insulation question

[SSCR]

Hey guys, I just picked up my insulation (kraft face fiberglass) and had a question. I'm going to use R-19 (6.25" thick) for the roof rafters and R-11 for the walls (2X4 construction). I have a second floor loft on the garage and need to insulate between the roof rafters (2X8 construction).

Do i need those plastic vents stapled between my rafters to vent or is the 3/4" between the kraft face insulation and the roof deck sufficent? I measured the insulation and it's more like 5 and 3/4" insted of 6 and 1/4" thick so I know I have over an inch of clearence between the insulation and roof deck.

The garage will be heated only when I'm out there, maybe twice a week at the most at 65 degrees at the highest and will have the garage overhead door opened daily since I actually keep a car in there I have no running water in there so I believe the humidity will not be like a house. I'm just worried about mold and ice dams, whatever they are. Thanks

 

[Shocker]

I used the foam vents and I would use them if you have the venting blocks. Cheap insurance. Might as well.

 

[dave67fd]

Do i need those plastic vents stapled between my rafters to vent or is the 3/4" between the kraft face insulation and the roof deck sufficent?

I would. You want to isolate the heat as much as possible from the insulation.

I have no running water in there so I believe the humidity will not be like a house.

Having running water in your house has little or nothing to do with the humidity level.

 

[SSCR]

I went with stapled baffles, thanks!

 

[SSCR]

I would. You want to isolate the heat as much as possible from the insulation.



Having running water in your house has little or nothing to do with the humidity level.

I would think washer/dryer, showers, dishwashers would add alot to the humidity in a home, no?

 

[Falcon67]

I would. You want to isolate the heat as much as possible from the insulation.


Having running water in your house has little or nothing to do with the humidity level.

Foam baffles don't do anything for heat gain - install radiant barrier before you put in the baffles if you are wanting to reduce heat gain.

And yes, water has a lot to do with the humidity levels in a house.

 

[R'Addiction]

Foam vents? Where do they go? New to this insulation stuff