Can you use half inch plywood on a roof?

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.

What is the minimum thickness of plywood for a roof?

Required Dimensions and Thickness of Plywood for Roofing

The minimum thickness of plywood used for roofing is 3/8^th of an inch.

What size plywood should be used for roofing?

3/8" APA rated sheathing is typically rated for a 24" span (distance between rafters) in a roof application. Half-inch is rated for a 32" span in the same application. Due to market pressures the 1/2" may actually cost less than the 3/8" and will be stronger.

How thick should roof sheathing 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 ply should I use on a flat roof?

A flat base is required to lay the roof covering on. This can be either Smartply OSB3 or good quality, structurally sound WBP plywood. A minimum thickness of 18mm must always be used.

OSB vs. Plywood: Which Should You Choose for Your Roof Deck?

Can you use pressure treated plywood on a roof?

The most important reason you shouldn't use pressure treated plywood for roof repair, is that new pressure treated lumber uses copper as its inhibitor.

Is it OK to use OSB for roofing?

Both OSB and plywood panels can cut and installed on a roof using conventional roofing equipment. They have similar structural characteristics, and can be used interchangeably.

What size OSB is used for roofing?

The most commonly used OSB size for roofing is 7/16-inch OSB. It's slightly smaller than 1/2-inch roof sheathing and considered the absolute minimum where rafters/trusses are spaced 24″ O.C. However, you can use other OSB sizes depending on your location and how far apart you space trusses or rafters.

Which is stronger OSB or plywood?

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. However, nail-holding ability controls performance in shear wall applications.

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.

What type of plywood is used on roofs?

5/8-inch plywood is the most common choice for roofing with 24-inch rafter spacing. It's also the standard for most roof applications because it supports roof loads in most situations. However, heavier roof loads may require 3/4-in CDX plywood for roof sheathing.

Can you use pine plywood roof sheathing?

Most builders opt for plywood or oriented strand board (some versions of which are manufactured in Maine) in sheathing the frames of new homes. But pine boards are the traditional option and they offer some advantages.

Do I need pressure treated lumber for roof?

As long as there's a good chance that moisture can reach the wood, it should be pressure treated. This is why the International Building Code requires that siding and structural lumber used for the last six inches of the structure above the ground is pressure treated.

What wood is best for roofing?

Cedar has earned a reputation for being strong, flexible, and weather resistant – qualities that make for an effective roofing shingle. Among roofing shingle manufacturers, cedar is the go-to material, all thanks to its durability.

How thick should flat roof insulation be?

An uninsulated flat roof has a U-Value of around 1.5 W/m2K. When insulating one, you're aiming for a value of 0.25 W/m2K or less. To achieve this, you should insulate your flat roof with insulation boards totalling around 150mm thickness.

What size timbers do I need for a flat roof?

The joists should be sized using either the TRADA span tables or BS EN 1995. The sizing and spacing will depend upon the loads imposed on them and the required span. Wherever possible, joists should span the shortest distance. Common joists sizes are 200 x 50mm, 175 x 50mm, and 150 x 50mm.

How much is a sheet of plywood for roofing?

Your price could vary depending on how much the roofing company charges for labor, but generally, you can expect to spend between $70 to $100 for each sheet of plywood. A 4 x 8 sheet of plywood covers about 32 square feet of roof area—and the average roof measures about 3,000 square feet.

Is OSB more water resistant than plywood?

OSB takes longer to get wet than plywood but also takes longer to dry out. When used as a roof sheathing, this tendency to hold moisture means it can degrade faster than plywood when exposed to chronic leaks.

What is the difference between OSB and plywood?

Plywood is made of many layers of very thin wood, called plys, pressed together with glue. It may be given a veneer ² top of hardwood, while the inner layers are typically made of softwood. OSB is made of many smaller pieces of hardwood and softwood mixed together in strands.

What kind of wood should I use for a shed roof?

With many colours and textures to choose from, both bitumen shingles and wood cedar shingles can finish your shed roof to a high-quality standard. Felt shingles will fit any shed roof with a pitch of 15º or more and they don't require any maintenance.

What is CDX plywood used for?

CDX Plywood is used primarily by contractors to build exterior walls and roofs. CDX plywood has one side veneer grade “C” and one side veneer grade “D”. The two are bonded together with glue which can withstand a little moisture. The APA would recognize CDX Grade Plywood as C-D Exposure 1 plywood.

Does a roof need plywood?

Aside from shingles and underlayment, plywood decking is one of the most important components in your roof. The plywood decking is integral in keeping your home free of unwanted water and mold. If the plywood has gotten wet, it can have a disastrous effect on the rest of your roof, especially the shingles.

Is it better to nail or screw roof sheathing?

The cheapest and easiest is to re-nail or, better yet, screw down the sheathing when you replace your roof covering. The other approach is applying an AFG-01 rated adhesive to enable the roof sheathing to withstand pressure to 250 pounds per square foot or greater.