If you ve reached your target depth but still have a few bags left over keep adding the material at an even depth throughout the space until all the bags your calculations called for are empty.
Insulating your roof space.
Insulate and air seal any knee walls vertical walls with attic space directly behind them in your home as well.
Flat roof insulation always requires professional insulation and damp roofs require professional assessment before work can be carried out.
A finished attic should be insulated much like the rest of the house with insulation in the walls and ceiling.
That means insulating the attic floor only not the walls and having vents in the roof.
Before insulating seal any air leaks and make roof and other necessary repairs.
To get the target r value from the product you chose use the number of bags your calculations showed that you needed to insulate your attic never fewer.
The technically correct approach depends on a number of factors.
Pipes water tank and loft hatch.
Before fitting any insulation to the sides of a pitched roof space any repairs to the roof should be completed once the insulation is in place it will be harder to spot any leaks inside the roof and any leaks will soak the insulation itself.
If it is located in a conditioned part of the house also remember to insulate and air seal your attic access.
If your attic is often used or perhaps you plan to convert it in the future you will need to insulate the inner surfaces of the roof.
How to insulate a finished attic.