Next you will need to place the foam board insulation between each joist as a test.
How to install insulating foam board in an attic.
Put the board between the rafters.
If you plan on finishing your attic then you cannot install it directly.
Step 2 install insulation boards.
You can use a foamboard adhesive to glue it in place.
Your board must leave at least inch gap between the board and the roof.
Do not nail the board into the roof.
Foam insulation boards can be attached to concrete walls as well and in such a case care should be taken not to chip the cement.
Remove any existing pieces of insulation that might have been covering the attic walls until now.
If it fits proper with no space between on either side of the board pick it up and put a thin layer of glue on.
No matter how much insulation you add to your home s walls floors and ceilings you re throwing your money away if you don t insulate your attic.