Roof Blocking On Top Of Rigid

Use a chalk box to snap chalk lines on the roof deck.

Roof blocking on top of rigid.

Ladder style blocking provides the structure of a torsion box which ties the fascia soffit. Install rigid insulation board in multiple layers with joints offset vertically and horizontally between adjacent layers. Note that there was no air seal at this location originally. I resided 17 years ago over one layer of continuous rigid insulation.

Install nailbase for cladding. Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance. Make sure there is sufficient soffit venting. Apply a new roof deck over the 2x4s and dry in with roofing felt or impermeable synthetic roofing underlayment.

The type of roof. This air seal is pretty darn good. Stagger the joints to. The plywood was fastened through the rigid foam to the rafters with long screws.

If you install just one layer you ll need to fasten the osb or plywood to the concrete slab with long tapcon screws that extend through the rigid foam. Butt the ends of the boards up together. Align the insulation boards with the chalk lines and lay them onto the deck. Rafters rest on the top wall plate.

Rafters are nailed to the plate not framed into it. Install one or two layers of tongue and groove osb or plywood on top of the rigid foam. This type of insulated roof assembly limits thermal bridging through rafters. This is the method a friend and i did in his basement.

After installing several layers of rigid foam above the roof sheathing these workers installed plywood above the rigid foam. This coverboard is also screwed down to the metal deck. I have to come clean here as well. The three layers of rigid insulation have yet to be installed over the top of the roof decking at this point.

Then on top of the rigid thermal insulation there should be a coverboard. They may extend a short distance beyond the wall to form the eaves and protect the sides of the building. When we do complex roofs in high snow load areas like ski resorts we typically have the roof deck act as the air control layer and provide a high level of thermal resistance at the roof deck either rigid insulation directly above the roof deck or high density spray foam directly under the roof deck and then we provide an over roof creating a vented space over the top of the entire assembly. Some are cut to fit the plate while in hasty construction they are merely laid on top of the plate and nailed in place.