DIY Builds
Photo by Anete Lusina Pexels Logo Photo: Anete Lusina

What is 3 8 plywood used for?

Roofing The Right Plywood for Roofing Many local building codes only require 3/8” plywood for roofing.

What's the cheapest roof to put on a shed?
What's the cheapest roof to put on a shed?

Roofing With MSR Roll Materials In most cases, MSR roll roofing is the cheapest shed roof material you can buy. Roll roofing is also the easiest...

Read More »
Do you need a Vapour barrier with Celotex in a shed?
Do you need a Vapour barrier with Celotex in a shed?

Vapour barriers The foil on foil backed insulation boards already does the same job, so a separate vapour barrier is not required. Instead, we use...

Read More »

Plywood consists of resin-coated veneer pieces pressed together under heat. That sounds straightforward, but things become a little more involved when it comes to choosing the right type and thickness of plywood for a job. Knowing the safety and strength requirements of any finished product makes it possible to choose the right type of plywood.

Plywood Grading and Rating

Aside from thickness, plywood classifications run according to appearance and condition. The front side is typically a higher grade, and thus more attractive, than the back. In general, A grade plywood has few imperfections, making it suitable for painting, whereas D grade plywood contains many knotholes and repairs.

Plywood for Furniture

Many furniture fronts, such as drawer fronts and cabinet tops, feature high-grade plywood with attractive veneer. Most cabinet construction uses ¾” plywood, or else ½” plywood, which is usually less expensive, and makes the finished piece somewhat lighter. Lower grade veneers are fine for interior areas, where appearance is not so important. Drawer sides only require ½” thick plywood, and drawer bottoms need only ¼” thick plywood. Thicker plywood is heavier, but it is also stronger and more durable. For instance, building a large tabletop from ½” plywood, supported only by legs at the corner, will result in a dinnertime disaster. Many table-building plans specify the thicknesses to use according to tabletop dimensions:

¾” plywood for smaller table tops, up to about 18” x 24”

1” plywood for tops up to 24” x 36

At least 1”, and, even better, 1 ½” for larger tables

Plywood is a popular choice for building entertainment units and shelving. However, while ¾” plywood may work fine for shelves less than 30” or so in length, the likelihood of mid-shelf sagging increases with shelf length. Using a thicker plywood helps reduce sag, especially over wider spans, thus avoiding potentially dangerous occurrences involving falling objects and collapsing furniture. Another way to avoid such a problem is by using wood edging to strengthen the shelves, or by installing mid-span supports.

Proper Plywood Choices for Safe Flooring

Plywood plays an important part in ensuring safe and durable flooring. Floors are composed of many different layers. The finished flooring sits on top. Next down is the underlayment, which provides the smooth surface needed for installing the top. Different surfaces require different underlayment, but all underlayment must be a thin but strong layer upon which the finished flooring surface rests. Floor underlayment typically uses 5/8” plywood. Beneath the underlayment is the subfloor, which requires the use of a thicker product, at least ¾” thick, perhaps more if the distance between floor joists is large.

Plywood for Walls

Can I use OSB to build a shed?
Can I use OSB to build a shed?

A shed's walls and roof are usually made of oriented strand board (OSB) because it's the least expensive siding option. That's why sheds and homes...

Read More »
Should I paint the inside of my shed?
Should I paint the inside of my shed?

Painting and treating the inside of your shed simply provides it with a protective but attractive finish that helps to transform the shed from a...

Read More »
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »

Only use exterior grade plywood anywhere where weather exposure is a concern. Interior plywood is not waterproof and its use in outdoor applications may result in serious building complications. Furthermore, exposure to weather compromises the integrity of the material, leading to collapses and weak spots that can cause serious injury. The plywood used to sheath house frames does more than provide a surface on which to install the siding on the house. It also makes the structure stronger by connecting all the studs together. On top of that, structures with siding only connected to the plywood sheathing require a thicker plywood. If the siding is attached to the studs, thickness is not as much of an issue. Using ½” thick plywood for walls is standard, although the International Residential Code specifies only 3/8” wall sheathing when studs are spaced 16” apart and the siding is attached to the studs and not just the plywood. For buildings with siding attached only to the sheathing, the IRC requires ½” plywood.

The Right Plywood for Roofing

Many local building codes only require 3/8” plywood for roofing. Spending a little extra money, and using ½” or even 5/8” plywood results in a longer lasting and safer roof. Plywood that is only 3/8” thick often will not support someone working on a roof, especially if they are big and/or there is a lot of space between trusses and rafters. Handling heavier weights is also important in high snow areas. Additionally, using thinner plywood for roofing provides less material for shingles to attach to, which makes it easier for the shingles to fly off in high wind situations. Consider the requirements of the finished product when choosing plywood thicknesses. It is not worth spending the time to craft a piece of furniture that will begin to sag in a relatively short time. The same goes for construction. Consider the weather conditions of the building site, especially high winds. It takes only one severe storm to prove the worth of spending a bit of extra money on thicker plywood.

What size shed do I need for a lawn mower?
What size shed do I need for a lawn mower?

The right size shed for the job is a 10 foot by 16 foot option. With those dimensions, you have enough room to comfortably house a large mower and...

Read More »
What is cheaper CDX or OSB?
What is cheaper CDX or OSB?

Cost. If you are big on saving, then you would want to go with OSB since it is a cheaper version of CDX. However, in as much as CDX is more...

Read More »
How much weight can a 4-inch slab hold?
How much weight can a 4-inch slab hold?

A 4-inch thick concrete can support upto 40 pounds of weight. Weight should not exceed 40 lbs/sq ft on an undetermined 4-inch slab. 80 lb/sq ft in...

Read More »
What is the maximum size porch without planning permission?
What is the maximum size porch without planning permission?

three square metres Limitations of the porch the ground floor area (measured externally) would not exceed three square metres. no part would be...

Read More »