How Much Space Between Insulation And Roof

Insulation is technically a solid with a lot of air in it therefore it is not an air gap.

How much space between insulation and roof.

Typically fiberglass or cellulose are the material choices. Air gaps larger than this work well too they promote ventilation on the foil and help keep the air dry and the air temps lower. If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters. Here are four approaches i recommend you investigate for insulating your attic.

R value for loose fill per inch is between r2 and r4 higher value with. Apply a 2 inch layer of spray foam insulation r 10 to r 12 directly to the interior surface of the roof sheathing. Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies.

With a warm roof the usual process is to split the insulation into two layers. This is one of the two most common types of insulation. Often installed into wall cavities as a way to retro fit walls lacking insulation it can also be blown into unfinished attic spaces. Typically we suggest you have an air gap between 1 2 and 3 4 for the radiant barrier to work.

You will however have to follow up with great stuff foam to ensure filled gaps if you go that direction. If the current gap is 3 4 the most you could do is insert 1 5 max of insulation.