How Much Space Between Insulation And Roof

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.

How much space between insulation and roof.

With a warm roof the usual process is to split the insulation into two layers. 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. From the sound of it the roof has already been framed and that limits options. Panels of polystyrene come to mind because their r value is better per inch of thickness than roxul pink stuff.

Apply a 2 inch layer of spray foam insulation r 10 to r 12 directly to the interior surface of the roof sheathing. 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. R value for loose fill per inch is between r2 and r4 higher value with. If the current gap is 3 4 the most you could do is insert 1 5 max of insulation.

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. Insulation is technically a solid with a lot of air in it therefore it is not an air gap. This is one of the two most common types of insulation. You will however have to follow up with great stuff foam to ensure filled gaps if you go that direction.

Typically we suggest you have an air gap between 1 2 and 3 4 for the radiant barrier to work. Typically fiberglass or cellulose are the material choices.