How Much Should Roof Sheathing Overhang

Choose an exterior c d grade.

How much should roof sheathing overhang.

Thickness will range from 3 8 to 3 4 inch depending upon local code. Overhangs can vary from a few inches to a few feet depending on preference. A typical metal roof overhang may be 2 to 4 inches or even less. However the suggested width of an overhang is between 12 and 18 for eaves and no more than 8 for rakes.

This would add another 3 4 to the thickness. Too little can allow water to seep into rake or fascia boards. Measure up the rafter 45 3 4 inch from the cut end of the truss tail and snap a line along the trusses. That said overhangs can extend as far as 2 without the need for external supports.

Too much overhang and the shingles could blow off in high winds. When ordering the sheathing divide the total number of square feet of roof surface by 32 square feet a 4 x 8 panel and add an extra 15 for waste. Metal is usually installed on rafters or strip sheathing rather than the solid decking used under other materials. It is at 45 3 4 in.

This is to just enough to cover the 3 4 x6 actual fascia. 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. 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 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.

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.