What thickness of plywood do you need for a roof?
Most Common Thickness
The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. It will support roof loads for most situations and is the standard for most roof applications. Roofs with very heavy loads may require 3/4-inch thickness.
What material is used for roof decking?
Sheet decking
OSB (oriented strand board) is the most common type of decking used on roofs today. It’s made up of wood chips/strips compressed together to form a flat 7/16” sheet. Plywood comes in several different thicknesses (⅜”, ½”, ⅝”, and ¾”) depending on the span of the rafters.
Is sheathing the same as decking?
While some roofing contractors use different terminology, roof decking and roof sheathing are the same thing. But now that you know they’re the same thing, what is roof decking (roof sheathing)? Roof decking (or roof sheathing) is the wooden boards that make up the foundation of your entire roof system.
What can I use for roof sheathing?
Oriented Strand Board (OSB) or plywood can be used, although plywood will provide higher nail head pull-through resistance. Use panels rated as “Exposure 1” or better. Install sheathing panels according to the recommendations of the Engineered Wood Association (APA). Use panels no smaller than 4 feet long.
Is OSB good for roof decking?
OSB is now the most-used sheathing and subflooring material for new roofs and roof replacements. OSB is currently selling for less than plywood by approximately $3 per sheet, meaning a savings of several hundred dollars per conventional home.
How thick should roof OSB be?
Standard roof sheathing thickness is ½” to ⅝” thick. If you are using OSB for your roof deck, then ⅝” is the recommended thickness. For plywood, which is slightly stronger than strand board, ½” thick is appropriate. Another factor is how far apart your trusses or rafters are spaced.
What is OSB roof decking?
Oriented strand board (OSB), an engineered wood panel, is an economical alternative to plywood. The two products are largely interchangeable, but OSB roof sheathing has a slightly lower tolerance for moisture. Manufacturers mitigate this with water-resistant treatments.
What thickness OSB for shed roof?
Use the correct thickness of board for the proposed use
The thickness of OSB that you need varies on where it is used in a building. Typically 3/4″(18mm) for floors and 3/8″ (9mm) for walls and 1/2″ (11mm) roof. Also make sure that you get your supporting timbers at the correct spacing.
Is OSB better than plywood?
Wood fiber is used more efficiently in osb. Osb is stronger than plywood in shear. Shear values, through its thickness, are about 2 times greater than plywood. This is one of the reasons osb is used for webs of wooden I-joists.
Which side of OSB goes up on roof?
OSB roof panels should always be installed with the grade stamp facing into the attic and the screened surface (with the nail guide lines) facing up. When the grade stamp is covered by roofing, the building inspector will not be able to confirm that the correct OSB roofing panel was used.
Should there be gaps in roof sheathing?
Quote from the video:
Quote from Youtube video: And we'll lay the lay the decking the OSB. And as you can see there budded right now we don't want this we want a gap of at least an eighth of an inch for expansion purposes.
How do you lift OSB on a roof?
Quote from the video:
Quote from Youtube video: The other one is not much better. But then I was like hey you know I could cut some little wedges and shuffle OSB up to the roof using those two spares. So let me show you how this works.
How far should roof sheathing overhang fascia?
The best installation method is to leave a gap between the drip edge and the fascia board, about the width of a finger. The shingles should also overhang the drip edge 3⁄8 to 1/2 an inch.
How do you lift heavy plywood?
Lean the plywood sheet on its long edge and slip the rope around the two bottom corners. Then reach over the sheet, grab the rope in the middle and lift, steadying the sheet with your free hand. With the 4×8 secured between your arm and torso, it’s easy to walk without losing your balance or straining a muscle.
Does sheathing overlap fascia?
In view A, the sheathing is started flush with the tail cut of the rafters. Notice that when the fascia is placed, the top edge of the fascia is even with the top of the sheathing. In view B, the sheathing overlaps the tail end of the rafter by the thickness of the fascia material.
What goes on first roof or fascia?
Fascia and soffit are installed after the roof installation is finished. It is ideal that soffit and fascia materials be installed before you place tiles or any other type of roofing material on the roof.
Do I need a Subfascia?
Though not required by building codes, the reasons for subfascia have more to do with evening out the rafter tail irregularities and providing structural support for the roof edge and gutters. Not all rafter tails are exactly the same length.
What is the typical overhang on a roof?
There is no true standard size for overhangs, but typical overhangs that are used for protection from rainfall are 16-18 inches wide. Overhangs wanted for shading should be minimally 24 inches. More commonly, they are 36 inches wide or more.
How much overhang should a deck roof have?
Typically, a porch overhang should be at least 12-inches long. However, they can range from two feet to very minimal in length depending on the area’s climate, so be sure to account for the amount of rainfall you might expect. Drier climates require minimal overhang length and wetter climates require longer overhangs.
Can roofs be flat?
Homeowners can choose among three kinds of flat roofs, says Bruce O’Neal, vice president of Matthews Roofing, which has been keeping Chicago’s many flat roofs dry since 1934. What are the different types of flat roofs? Built-up roof (BUR), modified bitumen roof (MBR), and rubber membrane roof (EPDM).
