Proper Insulating Roof Ceiling

Sprayed against the underside of the roof deck it seals against air movement eliminating the need for a vapor barrier or ventilation.

Proper insulating roof ceiling.

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. Unvented hot roof design cathedral ceilings are also an option. If you have an attic there are quick ways to insulate the ceiling from above after drywalling it. Foil faced batt insulation is recommended in cathedral ceilings because it offers the permeability rating required for use in ceilings without attics.

A cathedral ceiling is a sloping and pointed ceiling which is usually high and open. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. R value is a measure of insulation s ability to resist heat traveling through it.

The general consensus is if in doubt attic insulation takes priority over direct roof insulation. For example cathedral ceilings built with 2x12 rafters have space for standard 10 inch batts r 30 and ventilation. Water is insulation s enemy. When tom insulates a cathedral ceiling or a finished attic he also turns to foam.

It provides an open airy look and feel to the room and they are often in demand among home buyers. Cathedral ceilings are a feature in many homes that add to value to the house because the high ceiling tends to make rooms look larger. The hot roof design allows more insulation to be installed in the roof cavity as the need for a vent space is eliminated. When the ceiling is a cathedral type then you must provide a space between the roof decks and the ceiling in order to have room for insulation and ventilation.

It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. It s easier to knock out in a weekend and it s more relevant to most people s goals when it comes to insulation. Illustration by ian worpole. How to put insulation in a ceiling before drywall.

Box out light fixtures. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. The higher the r value the better the thermal performance of the insulation. There s a difference between insulating the ceiling and the actual roof slope.

Insulation level are specified by r value. The table below shows what levels of insulation are cost effective for different climates and locations in the home.