There are three types of blown in insulation.
Proper way to insulate a roof with blown in insulation.
Spray foams are used in the attic or.
Insulate and air seal any knee walls vertical walls with attic space directly behind them in your home as well.
If you re insulating from scratch put the right vapor barrier in the right place though some batts come with a paper or foil facing that can act as a vapor barrier tom silva prefers to use 6 mil polyethylene sheeting cut to fit between the joists and with seams sealed by foil tape to prevent moisture from seeping into insulation.
If the studs are 16 5 inches on center and you re using batts made for 16 inches you ll have a crack on each side that air can move through says tom.
Basically if you spray or stuff insulation into a wall cavity in an existing building pay close attention to the type and condition of the wiring that may be in the cavity.
High density damp spray is used in the attic or walls.
Loose fill insulation is blown into the attic or walls.
Blown in blanket is a loose fill material held in place in walls or ceilings by netting.
To insulate the roof itself you either use spray foam or retrofit with it with rigid foam board.
Some common insulation methods can actually cause long term damage.
Roughly a quarter of the average home s heat is lost through the roof.
Rigid board insulation is intended for use in confined spaces such as exterior walls and cathedral ceilings.
Fiberglass insulation gets its r value from the amount of air it traps between its fibers.
The three most common types of blown in insulation are loose fill fiberglass cellulose and rock wool each with its own pros and cons.
Before insulating seal any air leaks and make roof and other necessary repairs.
An advantage of spray foam is it s quick whereas foam board needs to be cut and measured which can be a chore.
In this case it s best to use cavity filling foam or blown in insulation.
Rather than insulating the whole home and potentially causing problems like excess humidity you can properly seal the attic of an old house.
If you re insulating the roof directly.
If it is located in a conditioned part of the house also remember to insulate and air seal your attic access.
Insulating the attic and roof.
Because blown insulation comes out as chunks of cellulose or fiberglass it does a better job of filling every crevice of the attic.