Roof Blocking On Top Of Rigid

Use the irc to determine foam thickness if you choose to install rigid foam on top of your roof sheathing the foam has to be thick enough to keep the lower layer of roof sheathing above the dew point in the winter.

Roof blocking on top of rigid.

Tape the seams on the second layer. A barrier of moldable or preformed rigid material which blocks the entry of wind driven moisture at openings between the field tile and trim tile or the field tile and the flashing. Then a second layer of plywood sheathing and asphalt shingles following the steps explained in this article. Apply peel and stick membrane to connect and seal the house wrap to the roofing membrane.

A roof with a run of more than 23 feet. Make sure all seams are properly lapped. Good non adhered roof underlayment made air tight with taped seams and air tight connections to the air control of adjacent assemblies. This insulation should be screwed down to the metal deck.

Close off the rafter bays with rigid foam or plywood. We live in zone 5 suburb of chicago and are hopefully about to put rigid foam above the roof sheathing on just the northeast roof portion of our roof. This blocks the cellulose from spilling out into the soffit space. If the foam is too thin the roof sheathing will be cold which can lead to problems with condensation or moisture accumulation.

On the gable ends this was pretty easy. A roof with a 1 2 pitch or a rise of 1 2 the width of the building and a run of 12 feet. The rafter length is 16 11 6 or 16 feet 11 6 12 inches. Rigid thermal insulation on the top of this air control layer in two layers at least with the joints off set horizontally and vertically.

As industry we wish to make every effort to properly state our recommendations to you the. 4 of polyiso under 4 of eps all above the original roof sheathing. This coverboard is also screwed down to the metal deck. For example if the run is 27 feet find the.

One of the keys to over roofing is to tie the air control layer of the roof assembly to the air control layer of the wall assembly. To create the channel we start by extending the zip system sheathing and tape above the top plate of the wall to the height of the rafter heel minus the depth of the air channel. This foam is applied over the top of the membrane that came down from the roof deck catching the wall control layers. Install two layers of rigid foam with the seams offset.

The osb is rigid enough to prevent it from being crushed when the cellulose is packed into place. No matter which option is chosen below the membrane this is how all tpo roofs are sealed at the seams. Remove enough siding so that you can get to the house wrap and seal it to the roofing membrane with flashing tape.