Make sure you place the plywood at a right angle to the joists of the roof.
Shed roof insulation techniques.
Cut and fit strips of 24 gauge sheet metal between the masonry chimney and the surrounding wood framing.
I m insulating my shed and i have a cathedral ceiling.
An air barrier is just that it keeps the air outside from getting in and the inside air from getting out.
You can also use closed cell spray foam insulation which also acts as a vapor barrier.
Start with clean and dry insulation staple the kraft paper batt to the sides of the studs and cover the insulation with drywall or plywood to keep the insulation relatively dry throughout its life.
A common type of wall insulation for insulating sheds is an air barrier.
They might be called insulation chutes.
These foam pieces are as wide as the rafter spacing and form a channel for air to flow between the top of the insulation and the roof sheathing.
Based on your description marine zone 4 minimum r10 but i would go r20 3 inches and then fill then interior cavity with roxul r23 pressed to the roof deck and then sheetrock it in.
Use caulk and expanding foam the fire blocking type sealant to close air gaps around pipes ducts and electrical wires where they enter the attic.
You wrap the shed in the air barrier and then put siding of your choice over it.
Polyurethane closed cell spray foam 7 50 sq.
All insulation products have many different brands to choose from and not all are of the highest quality.
Insulation will get moist and attract mold if exposed.
In this energy smart homes article senior editor martin holladay explains how to insulate a vented low slope shed roof using a combination of intake vents and cupolas.
Step 1 install and nail the plywood place the plywood onto the roof of your shed in such a way that it acts as sheathing for the roof s structure.
I ve also heard that if foam board is tight and sealed properly roof sweating is no issue.
I would make the shed roof unvented and put poly iso rigid foam on the top of the roof.
Use the fire blocking type.
You can use rigid insulation between the floor joists and use strapping or blocking to hold the insulation in place.
Initially i was going to fit foam board in between the rafters and give no kind of attic or ventilation space but then i was made aware that the roof needs to breathe or else it would sweat and the rafters would rot out.
Below is a ranking from highest price to lowest of the various insulation types you can use for your shed.
They make thin foam pieces that you staple to the inside of the roof sheating before you put the insulation up.
It does not matter if your shed roof is old or new there are several insulation techniques you can use.
Iso rigid foam 1 20 sq.