Proper Insulating Roof Ceiling
Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be.
Proper insulating roof ceiling. The table below shows what levels of insulation are cost effective for different climates and locations in the home. There s a difference between insulating the ceiling and the actual roof slope. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. If you have an attic there are quick ways to insulate the ceiling from above after drywalling it.
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. 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. 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. How to put insulation in a ceiling before drywall.
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. Water is insulation s enemy. It s easier to knock out in a weekend and it s more relevant to most people s goals when it comes to insulation. A cathedral ceiling is a sloping and pointed ceiling which is usually high and open.
When tom insulates a cathedral ceiling or a finished attic he also turns to foam. For example cathedral ceilings built with 2x12 rafters have space for standard 10 inch batts r 30 and ventilation. If you don t have an attic however there is. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
It provides an open airy look and feel to the room and they are often in demand among home buyers. R value is a measure of insulation s ability to resist heat traveling through it. Insulation level are specified by r value. Illustration by ian worpole.
Unvented hot roof design cathedral ceilings are also an option. Sprayed against the underside of the roof deck it seals against air movement eliminating the need for a vapor barrier or ventilation. The general consensus is if in doubt attic insulation takes priority over direct roof insulation. Foil faced batt insulation is recommended in cathedral ceilings because it offers the permeability rating required for use in ceilings without attics.
The hot roof design allows more insulation to be installed in the roof cavity as the need for a vent space is eliminated. But its open cell structure still allows moisture to escape.