Wood Roof Dimensions

The roof load is composed of a dead load and a live load.

Wood roof dimensions.

Chapter 7 ceiling and roof framing 40 ceiling joists 40 flush ceiling framing 42 post and beam framing 42 roof slopes 44 flat roofs 45 pitched roofs 45 valleys 48 dormers 48 overhangs 48 ridge beam roof details 49 lightweight wood roof trusses 49 chapter 8 wall sheathing 53 types of sheathing 53 corner bracing 54. The first step in a free roofing estimate is measuring the roof dimensions. A 12 in 12 pitch is a steep 45 degree angle roof. You will need to express this size in terms of square feet.

This calculator matches up with 90 of the applications in the 2012 international residential code book. This tells you the size of the beam needed to support the porch s roof. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. With less than 4 supports a special.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Then round it up to the nearest inch. The thickness of plywood used for roof decking depends on the roof slope the spacing of. For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.

Wood roof shingles are typically 16 18 or 24 in length and up to 13 in width but limited to 8 in width in some building codes. Most interior beams need to include the roof load. All end joints occur in line on every other support figure 6. Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure.

All pieces are supported on three supports. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. If there is are any questions about anything else then you should contact your supplier or an engineer. Outside of the u s a degree angle is typically used.

Many factors affect thickness. The dead load is constant and is estimated as 10 pounds per square foot for wood framed construction. See the image below for more explanation on rise run and pitch. It has been my experience to never use a beam smaller than a two ply 2 x 8.

In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. It is always better to have a large rafter rather than be concerned with a sagging roof. The live load depends on the maximum snow load in your area. Carson dunlop associates sketch left illustrates the typical wood roof shingle application pattern.

4 tongue and groove roof decking.