When installing a raised top plate place a band joist at the open joist cavities of the roof framing.
Insulating attic floor and ceiling.
If you decide on mineral wool such as glass wool or rock wool you will need to put down a damp proof membrane.
On the other hand if your attic is finished and currently used as living space you will need to add insulation behind the ceiling and ceiling walls.
Not sealing other ceiling penetrations.
Since the ceiling in the attic is too low to make it into a living space you should only insulate the floor.
In these designs take out attic.
Insulating in this way will allow the heat from the other floors to pass through to warm the attic but keep it from being lost through the roof.
If only the living space will be insulated wrap the insulation around the room s walls and ceiling and then continue along the floor of the non living space.
House below it and leave the attic cold.
Insulating a finished attic there are two basic ways to insulate a finished attic.
Similarly a flat ceiling takes out the cathedral style slope of attic ceilings with joists that run parallel to the attic floor and are attached to roof rafters.
Look closely at the attic floor and you ll likely see dozens of holes where wires pipes hoses vents and other mechanical components poke up into the attic.
In practical terms you can choose between mineral wool or insulation boards.
So insulating the floor of the attic is not only the best solution but it is also the simplest and cheapest.
This is particularly imnportant if you have heating and air in the garage.
The raised top plate design also minimizes windwashingof the attic insulation where air entering the soffit vents flows through the attic insulation.
The small gaps around these penetrations allow warm air to seep into the attic.
In this case the area behind the knee wall will be uncomfortably hot or cold.
Take the insulation up to your attic so that you are above the garage ceiling.
Take up the floor allowing you to see the joists.