Gap Between Roof Sheathing And Batt Insulation

Let s look at stucco cladding over foam sheathing over osb sheathing.

Gap between roof sheathing and batt insulation.

Press the poly into the sealant. Vented roof sheathing. Apply a 2 inch layer of spray foam insulation r 10 to r 12 directly to the interior surface of the roof sheathing. T he problem with the insulation against the sheathing expands.

The code calls for a minimum of 1 in. Actually panels marked sized for spacing simply mean that they are slightly smaller to allow for the recommended 1 8 gap see attached apa tt 055. The air impermeable insulation shall be applied in. Use special airtight electrical boxes see photo tip 5 or seal the poly to the electrical box with acoustical sealant.

Tape the seams in the poly with sheathing tape. This will keep the surface warm and help minimize condensation. There are lots of ways to insulate a low slope roof and most of them are wrong. In addition to the air permeable insulation installed directly below the structural sheathing rigid board or sheet insulation shall be installed directly above the structural roof sheathing as specified in table r806 5 for condensation control.

Seal the gap between the bottom plate of the wall and the floor with acoustical sealant or caulk. Updated on april 8 2016. If there is a roof leak the insulation will be damaged by the water leaving you with less insulating value. However it is considered good practice to leave a 1 8 gap between sheets and that is also recommended by apa but it is not required.

Generally spray foams have to be applied by a professional. Of airspace between the top of the insulation and the back of the roof sheathing. Air impermeable and air permeable insulation. Unless you re bulk filling rafter bays between 2 10 or 2 8 rafters with closed cell spray foam this approach.

For best performance the airspace in the vent chute should be a minimum of 2 in. This is best accomplishing by installing baffles on the underside of the roof sheathing in between every rafter prior to installing insulation between the rafters. Synthetic stucco photograph 8. You can then apply batt insulation around the foam without worrying too much about the air space.

First the easy stuff. The moisture is held in place by the insulation which allows for damage to the framing and other building components. Providing an air gap between the stucco cladding and the exterior face of the foam sheathing prevents the debacle we got with face sealed exterior insulated finish systems a k a.