Should Roof Sheathing Be Installed Perpendicular To The Rafters?
Should Roof Sheathing Be Installed Perpendicular To The Rafters?
Having stated that, it is critical that the sheathing be put with the strength axis perpendicular to the trusses/rafters. The strength axis is normally the long direction of the panel, although the grade stamp will specify it. The panel strength axis should never run parallel to the rafters.
These two orientations are very different in how they resist loads, and the code does not permit mixing them. For example, when used with trusses, the down-to-the-rafter direction is an uplift force, while a line load is perpendicular to the rafters.
If a roofing shingle is pulled off of a roof where the sheathing has been installed perpendicular to the rafters, and it lands on one of those panels which have been installed with its strength axis parallel to the rafters, it’s going to break out that panel pretty bad.
Should Roof Sheathing Be Over The Fascia?
A metal drip edge can help protect the sheathing beneath the roof, but if it is positioned too close to the fascia board, it can still allow water to be sucked into the fascia.
The optimum installation method is to allow a space approximately the width of a finger between the drip edge and the fascia board.
It is also recommended that the drip edge be installed at least 3-1/2″ away from the fascia board so it will not get wet.
How Often Does Roof Sheathing Need To Be Replaced?
Each type of roof sheathing has its own set of lifetime characteristics, according to Roofing for Pros.
Plywood, for example, may last anywhere from 15 to 40 years, and asphalt shingles might last up to 20 years, depending on the quality of the shingle.
Should Roof Sheathing Overlap Fascia?
A metal drip edge will help protect the sheathing beneath the roof, but water will still be sucked into the fascia board if it is too close to the fascia board.
The optimal installation approach is to leave a finger-width space between the drip edge and the fascia board.
What Is The Nail Fastening Schedule For Roof Sheathing?
As a result, the standard nailing schedule is 6 inches on center at supported panel edges, including gable-end walls, and 12 inches on center over intermediate panel supports.
However, for any panels 5/8 inch thick or less, a minimum of 8d nails (0.131 x 2-1/2 inches) are recommended.
It is also important to note that some building codes prohibit nailing into the edge of a panel less than 5/8 inches thick.
What Kind Of Sheathing Do You Use On A Flat Roof?
Plywood is commonly used for sheathing, however, particle board or oriented-strand board can also be utilized.
Although placing sheathing isn’t difficult, be prepared to work hard as you climb up and down a ladder and lift sheets of plywood. It is recommended that the sheets are cut so that they do not have to be carried too far.
What Causes Roof Sheathing to Warp?
Uneven Rafter Levels cause roof sheathing to warp. Warping is common when a roofer constructs a roof deck without ensuring the rafters are level.
Poor spacing between roof deck panels might cause the same issue. Issues with Underlayment: The underlayment must be dry and flat for the roofing to stay in place.
What Was A Roof Sheathing Material Commonly Used Before 1960?
Roofing felt was the most typically used sheathing material before 1960. Roofing felt had a tar base that helped it adhere to the roof deck and created a waterproof barrier.
In its natural state, however, it was not resistant to fire. The product is no longer used in modern construction.
Plywood sheets were commonly used after World War II because they could be mass-produced and made uniformly, which made them easy to install.
Although they are often used today, plywood sheets have drawbacks such as warping, curling, cracking, or splitting easily when nails are hammered through them.
