Building codes vary.
How thivk should attic i su.
If you raise the attic temperature the rh in both places would be the same.
The higher the r value the better the thermal performance of the insulation.
In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq.
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.
You are approaching the 43 deg dew point and some colder surfaces like windows you will get condensation there.
If you plan on placing the plywood around the perimeter of the opening or door and using it only to store light boxes or materials 1 2 inch thick plywood should suffice.
Having inadequate insulation or even worse having no insulation in your attic can be expensive.
Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.
Typical fiberglass batt insulation has an r value between 2 9 and 3 8 per inch of thickness.
The cost savings is insignificant compared to the extra support offered by the thicker material.
In fact the department of energy estimates that having no insulation in an attic can add 30 to a home s energy costs and with the average cost of heating.
Add the right kind of insulation.
The issue in the attic is that at 48 degrees f.
The coldest part of your house in the winter and the hottest area in the summer is the attic.
Attic flooring intended for a living space must be installed in compliance with building codes.
The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.
For this reason it s important that your attic floor have adequate insulation to prevent the attic from heating or cooling the rest of your home.
The thinner plywood is acceptable when the joist spacing is 16 inches.
Of vent for every 300 sq.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
Different types of insulation take up different amounts of space to insulate effectively.
If your insulation doesn t measure up and you need more installation can be done as a weekend diy project or you can call a professional installer to handle the job.
Some communities will allow homeowners to do their own construction but they are still subject to.