Shed roof insulation

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paulf615

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View attachment 10118
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So I already insulated the shed walls with r-13 insulation. Now I'm wondering what to do with the roof. I tried to take a picture of it but it didn't come out well (first picture) so I just took a picture form google on how the roof is framed (second picture). I need to insulate it and I was thinking just putting in the r13 In between the rafters but the rafters are all weirdly placed apart and I don't want to be cutting pieces of insulation or adding thin pieces to fill the difference because that can effect the r value. I also looked into the bubble insulation but that involved running horizontally across the studs and the bracing will get in my way and be hard to cut around. Another issue is the fascia is rotted out in certain parts and there's a gap between it and the roof so I want to make sure i insulate that good until I can get it replaced witch will probably be next year. So any ideas on how I can solve my problems or another way to go about insulating it.
 
You have what looks like a 2x4 across above the walls, I would fill in the rest, one beside each set of rafters and open a few vents in the soffet and add a box vent to the top of the roof and insulate the ceiling.
 
nealtw said:
You have what looks like a 2x4 across above the walls, I would fill in the rest, one beside each set of rafters and open a few vents in the soffet and add a box vent to the top of the roof and insulate the ceiling.
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Pricy but seems like my only option. i would also need to put up a board for the ceiling to hold back the insulation. Correct? What would you suggest for insulation? A faced r-30 or something like that so I can put it up from inside the shed. Also i would need to use the attic space as storage should i put a small hatch door in the gable end?
 
We don't see much paperbacked insulation out here, we would use batts friction fit and seal everything with 6 mil ploy vapour barrier to completely stop warm moist air from getting to the ceiling or walls.
If you are going to use the attic for storage you may want to use 2x8s instead for the ceiling so you can get enough insulation and have the joists exposed for storage.
The biggest heat loss will be at the top of the walls so it is important to have air flow above the insulation there and out the top to prevent ice dams.
As you will be spending time in the building and you have a heat source, I would install drywall just for the fire protection.
 
nealtw said:
We don't see much paperbacked insulation out here, we would use batts friction fit and seal everything with 6 mil ploy vapour barrier to completely stop warm moist air from getting to the ceiling or walls.
If you are going to use the attic for storage you may want to use 2x8s instead for the ceiling so you can get enough insulation and have the joists exposed for storage.
The biggest heat loss will be at the top of the walls so it is important to have air flow above the insulation there and out the top to prevent ice dams.
As you will be spending time in the building and you have a heat source, I would install drywall just for the fire protection.
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This almost seems as an overkill for such a small shed like I said it is only 8x10 so it shouldn't be too hard to heat. Also those batts friction fits i feel would be hard to install and there would be a lot of cutting involved because whoever framed my shed didn't line up the rafters with the studs and the spacing on the rafters range from 13" to 17" so I would have to custom fit each batt. I'm thinking 2x6 joists would be more than enough and maybe using a loose insulation would save me from a lot. Also that vapor barrier would cost me 50$ because that's the smallest quantity you can get, would this really be needed? And one more thing is the sheet rock. I planed on just covering the walls with 1/4in osb could I just use this on the ceiling too?
 
Cutting insulation to fit is the norm and there is nothing wrong with loose fill and if you are cutting a door into the gable end it would be pretty easy to do. KJeeping moisture out of insulation and wood framing is most important to prevent mold anjd one person spending time in a small room like this there will be more moisture than you can immagine. With you stud lay out being all over the place any sheet stack you use will have to be cut to join on the studs. Depending on where the door is drywall might be easier as you can get 10 and 12 ft length and have no but joists. But ya, what ever you feel comfortable using.
 
nealtw said:
Cutting insulation to fit is the norm and there is nothing wrong with loose fill and if you are cutting a door into the gable end it would be pretty easy to do. KJeeping moisture out of insulation and wood framing is most important to prevent mold anjd one person spending time in a small room like this there will be more moisture than you can immagine. With you stud lay out being all over the place any sheet stack you use will have to be cut to join on the studs. Depending on where the door is drywall might be easier as you can get 10 and 12 ft length and have no but joists. But ya, what ever you feel comfortable using.
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Is it possible to insulate between the rafters and not spend all the extra time to build a ceiling. If I have to cut Insulation any ways why can't I just throw up some batts right up in the rafters and fill the soffit with insulation? What issue would doing this cause?
 
nealtw said:
2 of these
http://www.homedepot.com/p/HUSKY-10...Polyethylene-Sheeting-RSHK610-25C-U/100651801
1 of these
http://www.homedepot.ca/product/red...60-millimetres-wide-and-50-metres-long/951143
1 of these to seal to the wall near the floor
http://www.homedepot.ca/product/pl-acousti-seal-vapour-barrier-sound-reduction-adhesive-825ml/972916
1 of these for the sealent.
http://www.homedepot.ca/product/9-inch-composite-caulking-gun/998617

All in $80.
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Does this vapor barrier go between the exterior sheeting and the insulation or between the insulation and the interior walls? Also I sort of already put up all the fiberglass Insulation for the walls is it possible to still put up the vapor barriers?
 
paulf615 said:
Is it possible to insulate between the rafters and not spend all the extra time to build a ceiling. If I have to cut Insulation any ways why can't I just throw up some batts right up in the rafters and fill the soffit with insulation? What issue would doing this cause?
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Garrenteed failure, You would need to make the rafters deeper to allow for insulation and air flow and as there not a common space for air flow you need venting in ever soffet bay and a ridge vent for both sides of the roof to be vented.
Just putting batts between rafters, leaves the rafters themselves not insulated and that why you need the venting so heat doesn't make it to the roof sheeting.

Doing that properly would be much more work
 
nealtw said:
Garrenteed failure, You would need to make the rafters deeper to allow for insulation and air flow and as there not a common space for air flow you need venting in ever soffet bay and a ridge vent for both sides of the roof to be vented.
Just putting batts between rafters, leaves the rafters themselves not insulated and that why you need the venting so heat doesn't make it to the roof sheeting.

Doing that properly would be much more work
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So the vapor barrier goes on the inside of the shed over the insulation?
 
So I've thought it through a bit and I've decided that ill use a 2in foam board insulation that has a r10 value. What ill do is ill attach the pieces so they run across the face of the rafters. That will leave the rafter cavity open,allowing for the underside of the roof and the roof rafters to be the same temp as outside. Then one I get to the bracing ill run the boards across the bracing making it so that there is a continuous opening from one end of the shed to the other, leading right up to a vent on the gable end keeping the entire tip of the roof cool and preventing any build up of heat. View attachment ImageUploadedByHome Repair1445800743.088471.jpg
The red being the foam
View attachment ImageUploadedByHome Repair1445800937.907545.jpg
Also by using foam I wouldn't have to use a vapor barrier. Correct? But I would still have to use a vapor barrier on the fiberglass insulation walls. The only issue I could see with this is the r value not being high enough but I think it will work for now and I can always double up the 2in foam in the future.
 
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Yes to most of what you are doing I think, Red tuck tape will seal the joins in the foam and to the poly on the walls.
The only ctach here is that foam in a living space should be covered with drywall. Even those foam boards that are rated for fire need drywall.
 
paulf615 said:
They don't sell this product in American homedepot or lowes is there another option like a construction adhesive or like a kitchen or bathroom caulking? Also can I just use the caulking/adhesive around the entire wall with staples so I don't have to use a lot of tape?
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Ya, I guess it will take some time for you guys to catch up to the advanced country to the north, And I don't know what else to say.
 
I don't know what they use down there, The insulators use a ton of it in every house up here, we use it to stick poly to concrete in the crawl spaces. You soon learm to hate it because it is black sticky crap and you do have to learn how not to touch it.
 
Bad news.
I walked into the shed today. Keep in mind the shed still isn't insulated on the back wall(10ft wall) and there's no insulation for the roof. Also there is no vapor barrier up yet. All there is is insulation on the side walls (8ft)
So when I walked In the floor in the corner was all wet. And I noticed that the bottom of the insulation on the closest wall was also wet. I found no place water could have leaked in so I pulled out the insulation on that wall and I found that the backside of the siding was damp, still no signs of leaks. My first thought was tere was no vapor barrier so condensation built up but the temp inside the shed is the same as out and the insulation on the other side of the shed is completely dry. Please help do I need to replace the insulation? Does this sound like a leak or condensation of some sort? What should I do to prevent it?
 
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Hose it down from the outside and find the leak, could be water spashing up or dirt too high in that area.
 
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