JonathanLaporte
Well-known member
I want to insulate the roof of my shed.
Now I'd like to know what are the risk of blocking the soffit vent?
Now I'd like to know what are the risk of blocking the soffit vent?
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12x18 shed can I block soffit?
- Thread starter JonathanLaporte
- Start date
p_mori7
Well-known member
Is there a vent in the roof ?
Probably not...most yard sheds don't have that.
Does the shed have trusses or rafters ?
Probably rafters...most sheds 12x18 or less do not have trusses, just 2x4 rafters to a 2x4 ridge beam (or similar).
Why do you want to insulate just the roof ?
Are the walls already insulated ?
Do you plan on heating your shed this winter ?
Probably not...most yard sheds don't have that.
Does the shed have trusses or rafters ?
Probably rafters...most sheds 12x18 or less do not have trusses, just 2x4 rafters to a 2x4 ridge beam (or similar).
Why do you want to insulate just the roof ?
Are the walls already insulated ?
Do you plan on heating your shed this winter ?
OP
JonathanLaporte
Well-known member
Is there a vent in the roof ?
Probably not...most yard sheds don't have that.
Does the shed have trusses or rafters ?
Probably rafters...most sheds 12x18 or less do not have trusses, just 2x4 rafters to a 2x4 ridge beam (or similar).
Why do you want to insulate just the roof ?
Are the walls already insulated ?
Do you plan on heating your shed this winter ?
Wall almost done
I have trusses
I plan to heat in winter.
I want I insulate between trusses to keep my small attic space.
James-W
Well-known member
A building that is 12 X 18 is not very big for a workshop, may I ask why you want to heat it?
p_mori7
Well-known member
OK, you use the bottom chord of the trusses for storage.
In that case I would just place the insulation right up against the underside or the roof decking. There will be no venting, so no need for soffit vents.
IF you have a ridge vent, then you need to leave the soffits vented, place a foam vent baffle all the way up to the ridge vent, and then put your insulation up against the baffle.
Do you have photos of your roof ?
In that case I would just place the insulation right up against the underside or the roof decking. There will be no venting, so no need for soffit vents.
IF you have a ridge vent, then you need to leave the soffits vented, place a foam vent baffle all the way up to the ridge vent, and then put your insulation up against the baffle.
Do you have photos of your roof ?
OP
JonathanLaporte
Well-known member
OK, you use the bottom chord of the trusses for storage.
In that case I would just place the insulation right up against the underside or the roof decking. There will be no venting, so no need for soffit vents.
IF you have a ridge vent, then you need to leave the soffits vented, place a foam vent baffle all the way up to the ridge vent, and then put your insulation up against the baffle.
Do you have photos of your roof ?
What worst could happen if these no ventilation between the deck and insulation?
bczygan
Well-known member
What worst could happen if these no ventilation between the deck and insulation?
Condensation on underside of roof sheathing, wet insulation, mold and roof sheathing rotting. No shingle warranty.
Steve in Mi
Well-known member
Condensation on underside of roof sheathing, wet insulation, mold and roof sheathing rotting. No shingle warranty.
If you want a second opinion, bczygan has been totally honest with you.
sands35
Well-known member
Install a ridge vent. Pretty easy afternoon job.
Install foam troffers to allow ventilation between the soffit and the ridge.
Install insulation. You may have to double the rafters if they are 2x4 and not 2x6.
Another easy day.
Sheet with plywood/OSB/Sheetrock.
One more day. (bare insulation will look horrible in a few years and kraft faced will get holes in it - and pose a fire hazard.)
Yes, not venting will cause condensation if you don't insulate to R50-60ish. But if you do that, then you need to detail it for air leaks or use spray-foam.
Install foam troffers to allow ventilation between the soffit and the ridge.
Install insulation. You may have to double the rafters if they are 2x4 and not 2x6.
Another easy day.
Sheet with plywood/OSB/Sheetrock.
One more day. (bare insulation will look horrible in a few years and kraft faced will get holes in it - and pose a fire hazard.)
Yes, not venting will cause condensation if you don't insulate to R50-60ish. But if you do that, then you need to detail it for air leaks or use spray-foam.
Last edited:
digdug18
Well-known member
I wouldn't worry about not having any venting, so long as you properly insulate. Worst case honestly, mold. Or perhaps ice damming if you have gutters on it.
I don't have venting, and no issues, though I also spray foamed the heck out of it, so condensation is less of a concern. Closed cell fyi.
I don't have venting, and no issues, though I also spray foamed the heck out of it, so condensation is less of a concern. Closed cell fyi.