Spacing Between Insulation And Roof

In the winter humidity from the house s interior will get past the insulation and come in contact with the cold roof sheathing where it will condense into water.

Spacing between insulation and roof.

It is important that air is allowed to circulate between the roof covering and the insulation to avoid condensation a gap of at least 50mm 2 inch must be left between the insulation and the inside of the roof covering. If there is a leak the air flow ventilation will help dry out the moisture. Place between purlins if using them. By leaving an air space between the insulation and the sheathing we can have air flow over the framing.

For such constructions the principles and benefits of unvented attic construction are similar to that occurring in a single family residence. The code calls for a minimum of 1 in. A roof must be able to breathe. The idea here is after you have your high quality metal roof installed you will want to prevent the space underneath from heating up.

The solution is not to ignore the insulation but to add one component. When there are gaps or channels between the pieces of insulation you allow the air to flow between each one. Instead a dead space exists between the roof system and the top floor ceiling typically comprising of an acoustic tile system and no roof ventilation is provided. Of airspace between the top of the insulation and the back of the roof sheathing.

An air space between the insulation and the bottom of the roof sheathing is desirable. The same concept holds true for roof trusses. Roof decking insulation is a common method of providing yet another insulating barrier between the metal on top and the attic space below. Spacing of furring strips for metal roof when installing a metal roof over an existing roof insulate the spaces between the wood strips with rigid insulation to prevent condensation before.

Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. The gaps do not have to be more than 1 8 inch but they are important to the health of the roof the insulation and the house as a whole.