How Much Should Roof Sheathing Overhang

Too much overhang and the shingles could blow off in high winds.

How much should roof sheathing overhang.

This is to just enough to cover the 3 4 x6 actual fascia. Too little can allow water to seep into rake or fascia boards. It is at 45 3 4 in. This indicates the upper edge of the first row of roof sheathing leaving enough overhang that the subfascia and fascia will tuck neatly underneath when the time comes.

Measure up the rafter 45 3 4 inch from the cut end of the truss tail and snap a line along the trusses. However the suggested width of an overhang is between 12 and 18 for eaves and no more than 8 for rakes. Some slight overhang is recommended in conjunction with a drip edge flashing to prevent water from getting under the roofing and onto underlying wood. The drip edge also gives us a nice straight edge with which to align roof shingles slates or other roofing material.

Metal is usually installed on rafters or strip sheathing rather than the solid decking used under other materials. The edge of the shingles should hang over a roof between an inch and an inch and a half or between a half inch and three quarters of an inch if drip edge flashing is installed. Roof sheathing overhang on fascia. Drip edge varies in dimensions but typically the flange that nails to the roof surface is about 2 5 wide and the vertical edge that directs roof runoff down and away is about 1 5 in depth.

Overhangs can vary from a few inches to a few feet depending on preference. I ve trimmed my roof sheathing to run between 5 8 and 3 4 over the sub fascia. A typical metal roof overhang may be 2 to 4 inches or even less.