Osb and plywood come in thicknesses ranging from 5 16 to 3 4 inch and the thickness needed for a particular roof depends on several factors including rafter spacing expected load and roof design.
What plywood to use on a flat roof.
It is formed from multiple layers of wood bonded together with a glue and the grains run in alternate directions through each layer which ensures the board s strength is.
Look for something that s graded as exposure 1 or exterior.
This plywood is strong and durable enough for use in roofing framing and other exterior structural.
Plywood is made with an odd number of layers for optimal strength and performance.
Use it indoors or outdoors but avoid using for framing permanent structures such as a shed or a home.
Plywood boards used for the deck should be.
A minimum thickness of 18mm these will be able to span up to 600mm.
The minimum plywood for roofing.
Sheathing should be a minimum of 19 32 inch thick.
5 ply is a versatile type of plywood that is about 4 millimeters thick.
In addition to the thickness you also need to make sure that you choose plywood that s graded for outdoor use.
Plywood for a roof deck should be of marine grade and suitable for external use to bs en 636 or a bond class 2 or better complying with bs en 314 check.
What plywood should you use for a roof.
Roofs are framed with rafters or trusses which are rafters joined by internal braces so they install as a single component.
In roofing plywood is often selected due to its strength.
Roofing can also be improved by using extra insulation and fresh single ply membranes the effects of an extra insulation will be experienced by the cooler temperatures that will be enjoyed in the interior during the summer and the use of the single ply will definitely prolong the life span of the roof.
Rafters run from the peak of the roof.
8d ring shank nails should be used instead.
Never attach roof sheathing with staples.
One of the nice things about plywood is the variety of options you can buy.
Although the roof structure takes the majority of the weight plywood needs to be able to support the rest of the roofing system.
What size plywood should you use for your roof.
The industry offers a thickness of anywhere from 5 16 inch to inch.
The typical thickness range for sheathing is 3 8 to 3 4 inch.
Multi ply is a catchall term for plywood with seven or more plies.