Which Direction Should Plywood Go On A Roof

If used for floor or roof sheathing where the primary purpose is to carry loads perpendicular to the face of the sheets then it must be placed with the long direction of the sheets perpendicular to the supporting joists or rafters.

Which direction should plywood go on a roof. The irc meanwhile allows you to orient the sheathing in either direction for wind loads but includes an important exception. Roofs the minimum osb panel size is 24 inches in any direction and each sheet end must rest on a rafter. Osb is lightweight relatively inexpensive and strong enough to resist bending or breaking should someone walk on the roof. The strength axis is usually the long direction of the panel but the grade stamp will indicate it.

Plywood is a bit more expensive but is usually stronger and is often selected in cases where the roof covering is heavier such as for slate clay or concrete tile roofs. Place 2 pieces of wood about 8 foot long on the roof rack on the lengthwise. Align the long edge of the sheathing with the ends of the. Like most other things there is no one right answer for the plywood thickness of your roof.

Be very careful on hip roofs along the hip to make sure the strength axis does not mistakenly get parallel to the supports as that may result in the panel exceeding the maximum span allowed for that thickness. If you install plywood sheets tightly against one another the edges tend to pucker upwards when they expand. On center the irc wants the panels installed with their strength axis perpendicular to supports in other words horizontally to handle wind pressure. Plywood thickness for the roof.

Position the first piece of plywood or oriented strand board sheathing on the bottom edge of the rafter tails at one end of the roof. Provide a 1 8 inch gap. Oh and remember to prepare two other pieces of wood for later use. The face grain usually runs parallel to the eight foot side on a 4 x 8 piece of plywood.

Lay sheets in rows with the long edge horizontal to the roof bottom. Remember to place a distance of about 3 to 3 foot in between. If you re using 3 ply plywood panels of any thickness on studs spaced greater than 16 in. Contact the manufacturer of the product you re going to use for more information.

One of the most important factors when selecting the plywood for your roof is how thick each piece should be.