According to the u s.
Attic insulation no deep enough.
Many homes are leaky and have insufficient insulation in the attic.
Insulation levels are specified by r value.
Sometimes there is enough insulation in the middle of the attic and very little along the eaves.
This allows a lot of heat up to the attic.
Use unfaced insulation when adding more insulation to an attic that already has some insulation laying the rolls or batts at right angles to the floor joists.
For example 2x4s would do but that is a lot of extra work.
In an unfinished attic the process is simple.
Basically a traditional farm house type.
I might be minimized if i only screw pieces of 2x4s from place to place just to support the drywalls.
Department of energy it s recommended that attics have an r 38 to r 49 or about 12 to 15 of fiberglass or cellulose insulation.
But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.
In winter but it is all bearable.
It is important that the insulation be evenly distributed with no low spots.
Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.
Because the simplest and cheapest way to insulate an attic is to add material to the floor.
One obvious solution would be to screw lengths of wood along the rafters to increase the depth.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
In other words the entire vent opening doesn t count as vented space.
First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
Plan to pull up the flooring and layer new insulation on top of the old.
When you re blowing insulation it can get dusty and hard to see whether you ve got it deep enough around the entire attic.
How much should i add.
If your attic insulation covers your joists and is distributed evenly you probably have enough.
Warm spaces have less condensation risk than colder space so when you add insulation to the attic floor you re intentionally blocking some of that heat from keeping the attic warm.
Our house from 1900 has no insulation.
We do wear hats etc.
R value is a measure of insulation s ability to resist heat flow.
Bust out the existing slab and excavate deep enough to install at least 4 inches of inch to 1 inch washed gravel or river rock.
Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live.