To stabilize the rafters support the roofing material and hold the entire roof together roof sheathing is installed.
Roofing over tg sheathing.
If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.
Add the thickness of the true fascia 15 16 in in this case.
The fully adhered membrane wrapped down over the cut back roof deck to tie into the wall water control layer and air control layer photograph 11.
Add an inch and a half for subfascia strike a line.
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.
The most common uses are as sheathing in walls flooring and roof decking.
Starting with how to place the first row of sheathing we cover fastening methods the use of h clips stagg.
If your roof was not a low slope roof if it was say a roof with a 4 in 12 pitch you could install metal roofing over purlins with roofing underlayment asphalt felt under the purlins and above the roof sheathing.
It spans the rafters to support the roofing and in the case of panel sheathing such as plywood or osb it acts as a diaphragm with the walls to resist horizontal loads.
As more layers of roofing were added there would be little chance that water would work its way through to the roof deck.
Roof sheathing attaches to the surface of the rafters or trusses to form the structural skin of the roof.
It is common to find older homes with 3 or 4 layers of roofing over the original roof.
Measure from the edge of the plywood outside of the wall over to whatever the overhang will be and square a line up to indicate the end of the truss tail.
But you must take care to install shingles correctly so they lie flat.
On the gable ends this was pretty easy.
Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones.
As more and more layers of the roofing kept being added there was a minimal chance that any water was going to be able to work its way through your roofing deck.
On the front of the roof edges the original roof deck sheathing was cut back flush with the wall and the fully adhered membrane folded down around the rafter tails to catch the.
Product may vary by store.
Roof sheathing basics the skeleton of a roof is formed with rafters or trusses generally spaced 16 inches or 24 inches apart from the center of one rafter to the center of the next.
Osb is a material with high mechanical properties that make it particularly suitable for load bearing applications in construction.
We go in depth on how to install roof sheathing.
