I'm getting ready to insulate the space between the ceiling rafters in the man cave. They are 2 X 6's and then I'm going to put plywood down on the top of the rafters for storage. We upgraded this area of the ceiling/roof to be able to support the weight.
So, I'm wondering if I should use R-30 9" thick insulation and squish it a little, or go with R-19 6" thick which I know will work.
I'd prefer the R30, but not sure if compacting the insualtion is going to defeat the purpose because I think there needs to be some air spacing in the fibers to insualte effectively?
Any insulation experts in the group?
Tony Hoffer said
Sep 22, 2011
I went R- 38 and skipped the boards on top.. use the most you can get without compressing it.
dashboard said
Sep 22, 2011
Don't squish! Squishing is a bad thing.
69SSConv said
Sep 22, 2011
What I did is placed 2x6 on top of the rafter (on edge) to get me the higher R-factor, that way I was not compressing it. So with the 2x6 (5.5"+ 5.5") I had enough to go with about 10" of blown in insulation under the plywood I layed down through the center. I used some rafter plates to hold them on top of the rafter 2x6.
BB502 said
Sep 22, 2011
R 30 squished is R 15
SShink said
Sep 22, 2011
Thanks guys.
Loren, I like your idea but I would probably do it with a 2 X 4 on edge so that I could use the 9" thick R30. I'll have to scope that out this weekend.
jim larson said
Sep 22, 2011
I used blown in fiberglass, the non -itchy type around most of the perimeter 12". I only used plywood on the center section which offered enough heights for storage space. Then built up the perimeter of the storage area so I could use more depth in those areas. Important to use the barriers so you don't block off air flow from the eves. Use standard R19 fiberglass bat insulation under the storage area. Used plastic for a vapor shield around the perimeter and craft face for under the storage area.
bowtie said
Sep 22, 2011
Don't compress it and definately use those shields where the rafters meet the roof so the insulation doesn't block airflow like what was said.
dashboard said
Sep 22, 2011
bowtie wrote:
Don't compress it and definately use those shields where the rafters meet the roof so the insulation doesn't block airflow like what was said.
Don't squish!
Dave Seitz said
Sep 25, 2011
Remember to put in the vents to the eaves so the insulation does not fill the eave. Blown in is the cheapest and is a mess when you do install it, check around if any insulation place is is hurting for work they can install faster and cleanup in less time then you can. One of the neighbors had guys blow the crap in and were out in 3 hrs cost was $225 labor. I could only get the machine for 4 hr blocks and had to go back twice for the machine to do the shed. Untill you have done it you do not know how bad it can be to install in a large area.
Chris R said
Sep 25, 2011
Pushrod is or was in the middle of putting insulation in his shop. You might consider calling him and see how he did it. I seen it in person but I couldnt tell you what he used or how he did it.
jim larson said
Sep 25, 2011
blew insulation in my house in the late 70's. No problem. When I did the garage a few years ago, they had a non-itchy fiberglass. No Problem, much better though. Blower came from the lumber yard where I bought the insulation. I used the cardborard rather than the plastic vents.
SShink said
Oct 15, 2011
Pulled the trigger and insulated the area that will have flooring over it with faced R-19 insulation today. I thought it would be cooler up there today, but man I probably lost 5 pounds sweating (not that it's a bad thing...)!
I got 3/4 done and had enough working on my knees. I'll finish the floor then build some walls to hold the blown in insulation, install the baffles, and blow it in. Should help a lot.
And no... I didn't squish!
I also added a 4th vent to help distribute the air more evenly in the space. Time for a shower!
I'm getting ready to insulate the space between the ceiling rafters in the man cave. They are 2 X 6's and then I'm going to put plywood down on the top of the rafters for storage. We upgraded this area of the ceiling/roof to be able to support the weight.
So, I'm wondering if I should use R-30 9" thick insulation and squish it a little, or go with R-19 6" thick which I know will work.
I'd prefer the R30, but not sure if compacting the insualtion is going to defeat the purpose because I think there needs to be some air spacing in the fibers to insualte effectively?
Any insulation experts in the group?
What I did is placed 2x6 on top of the rafter (on edge) to get me the higher R-factor, that way I was not compressing it. So with the 2x6 (5.5"+ 5.5") I had enough to go with about 10" of blown in insulation under the plywood I layed down through the center. I used some rafter plates to hold them on top of the rafter 2x6.
R 30 squished is R 15
Thanks guys.
Loren, I like your idea but I would probably do it with a 2 X 4 on edge so that I could use the 9" thick R30. I'll have to scope that out this weekend.
I used blown in fiberglass, the non -itchy type around most of the perimeter 12". I only used plywood on the center section which offered enough heights for storage space. Then built up the perimeter of the storage area so I could use more depth in those areas. Important to use the barriers so you don't block off air flow from the eves. Use standard R19 fiberglass bat insulation under the storage area. Used plastic for a vapor shield around the perimeter and craft face for under the storage area.
Pushrod is or was in the middle of putting insulation in his shop. You might consider calling him and see how he did it. I seen it in person but I couldnt tell you what he used or how he did it.
blew insulation in my house in the late 70's. No problem. When I did the garage a few years ago, they had a non-itchy fiberglass. No Problem, much better though. Blower came from the lumber yard where I bought the insulation. I used the cardborard rather than the plastic vents.
Pulled the trigger and insulated the area that will have flooring over it with faced R-19 insulation today. I thought it would be cooler up there today, but man I probably lost 5 pounds sweating (not that it's a bad thing...)!
I got 3/4 done and had enough working on my knees. I'll finish the floor then build some walls to hold the blown in insulation, install the baffles, and blow it in. Should help a lot.
And no... I didn't squish!
I also added a 4th vent to help distribute the air more evenly in the space. Time for a shower!
Before:
After: