How To Turn Attic Into Conditioned Space

You might open up your attic and find bare joists with fiberglass or cellulose insulation between the joists.

How to turn attic into conditioned space.

However when open cell foam is installed without a vapor barrier which appears to occur often in real world applications the foam will absorb the water. Fortunately this is a fairly easy fix. From my research it looks like the best option is to make the attic a conditioned nonvented space. I m unsure of what to do and i m unsure of the most economical way to do it.

Humid indoor air that escapes into the attic can condense on cold roof sheathing resulting in potential moisture problems. At least half of your attic space must be 7 feet high by 7 feet wide with a total of 70 square feet. That means you ll need 2x10 floor joists or maybe 2x8 in rare circumstances and at least 2x12 roof rafters. A fundamental requirement of an unvented attic assembly is the use of air impermeable insulation on the underside of the unvented roof to prevent air infiltration and exclude airborne moisture from the attic.

Open cell foam when properly installed with a vapor barrier should operate very similarly to closed cell foam. Once you convert attic space into living space you need to bring it up to the standards of modern building codes. Pull down stairs won t work for an attic room so you must add a permanent staircase. The missing piece of information is those miserable little beasts called the building and energy codes.

Currently the attic is vented and has zero insulation anywhere. Use closed cell foam insulation. Codes vary from place to place but the rule of 7 for using an attic as an actual room typically applies. Moving the insulation layer from the attic floor to the sloped roof brings the attic into the home s conditioned envelope and greatly reduces the energy penalties associated with attic ductwork.

That is it too will prevent moisture from penetrating into the attic area. The loss of conditioned air increases heating and cooling demand. Any water that leaks through the roof will pool on top of the vapor barrier and possibly next to the sheets of decking on the roof. The attic is fairly small at about 1 000 sqf total.

Fine homebuilding more musings of an energy nerd ventilation requirements in the covid era. Not addressed can lead to several problems.