Exterior Plywood

Exterior plywood is made for places where ordinary boards would not last. Exterior ply stays solid, even when the environment is not perfect. The sheet is simple to work with and suits many outdoor and semi-outdoor tasks. Some types give you better resistance to damp areas, while others offer extra strength for heavier workloads. Whatever the project, you get a panel that feels reliable and performs consistently outside.

What is outdoor plywood?

Outdoor plywood is made for use outside or anywhere exposed to changing weather. It is sometimes called exterior ply or exterior grade plywood. The sheets are built with durable layers and strong bonding so they do not come apart when exposed to rain, cold or heat. Different types offer a stable sheet for outdoor structures. That is why outdoor plywood is often chosen for sheds, cladding, roofing bases and many garden or exterior projects.

What is exterior grade plywood used for?

Exterior plywood is designed for places where boards have to cope with damp air, changing temperatures and everyday use. It is commonly chosen for exterior walls and roof sheathing, as well as for sheds, pool houses and other outdoor buildings where ordinary interior boards would not hold up.

This exterior grade plywood is also a good fit for covered and semi outdoor areas. It is used behind cladding, for soffits, partitions and wall linings in garages, carports and utility spaces where ventilation is present but direct rain is limited. The same outdoor plywood works well as a stable base under exterior flooring and sheltered decking systems.

In unheated spaces, exterior ply is often used to build cabinet carcasses, storage units and shelving systems. It performs reliably in garden buildings, garages and workshops where moisture and cold are part of the environment.

Types of external plywood 

Exterior plywood is designed for outdoor and semi-outdoor use, and on our website you will find sheets built to handle weather changes, moisture and structural loads. The panels differ by species, class, bonding strength and their level of performance outside. Here is a clear breakdown of the main options and what they offer.

• Standard exterior plywood is a practical sheet for general outdoor tasks. Works well in covered exterior areas, sheds, basic cladding and projects that need weather tolerance. A balanced, everyday option.
• EN636 Class 3 exterior plywood rated for tougher exposure. These boards use stronger bonding and more controlled veneer quality, giving better performance in damp conditions and structural outdoor builds. A reliable choice where long-term stability matters.
• Marine grade plywood is the highest-performing exterior sheet, built with high-quality veneers and waterproof bonding environments where maximum durability is essential.
• Hardwood exterior plywood is a denser, stronger option with a cleaner face and excellent screw-holding strength. Ideal for visible exterior panels, joinery and projects where appearance and durability must work together.
• Moisture resistant exterior plywood is a reliable choice for humid locations. Although not marine grade, it handles moisture in exterior spaces like garden, utility areas and sheltered outdoor structures.

Exterior plywood is available in a wide range of sizes: 2440 x 1220mm (8’ x 4’), 2500 x 1250mm (8,2’ x 4,1’), 3050 x 1220mm (10’ x 4’), 3050 x 1525mm (10’ x 5’) and 2500 x 1220mm (8,2’ x 4’). Thickness options run from 3,6-30mm. Grades vary by product and include B/BB, BB/CC, C+/C and marine grade options such as BS1088. Many boards meet BS EN 636 Class 2 or Class 3 for weather exposure.

Product standards include CE2+, CE4 and both structural and non-structural classifications. Exterior plywood on the website is supplied unfinished, smooth-sanded or with a decorative veneer. Most sheets have a square edge. Wood species used for the cores include birch, eucalyptus, keruing, meranti, pine, poplar, spruce, okoume, hemlock and combi core.

Formaldehyde levels is low E1. Fire ratings depend on the product and may be unclassified or certified to Euroclass B or Euroclass D-s2,d0. FSC-certified exterior ply is available where marked, providing an option for sustainable sourcing when required.

Benefits of using exterior grade ply

• Works well in outdoor and semi-outdoor areas.
• Handle changing weather without losing shape.
• Strong bonding keeps layers from separating.
• Suitable for sheds, cladding and roofing bases.
• Performs better than ordinary boards outside.
• Moisture resistance supports damp environments.
• Accepts paint, oil and protective coatings.
• Provides stable strength across the whole sheet.
• Works for both structural and non structural tasks.
• Reliable option for long term outdoor builds.
• Good screw holding for external joinery.
• Clean surface available on hardwood versions.
• Consistent thickness helps achieve level surfaces.
• Compatible with many sealants and weatherproofers.
• Reduces warping in humid conditions.
• Gives a strong base layer for exterior structures.

Why choose our exterior plywood?

• Exterior plywood from Sheet Materials Wholesale is supplied with reliable UK stock levels, consistent sheet quality and fast dispatch across the country. Exterior plywood, outdoor plywood and exterior grade plywood are available with trade discounts off the shelf, next day delivery on many sizes and quick nationwide delivery.
• Orders can be placed as single sheets, pallet quantities or full bulk loads. Competitive pricing and flexible minimum order quantities support both small and large projects. The full range of ext plywood is project-ready. Delivery is offered to residential and site addresses across the UK. Orders include tracking and a VAT invoice for trade use. Strong logistics, sustainable choices where available and consistent nationwide supply make Sheet Materials Wholesale a dependable source of exterior plywood for trade, DIY and commercial builds.

Tell Sheet Materials Wholesale your exterior plywood specification and quantity for a quick quotation, low wholesale pricing and dependable UK service. Order bulk exterior plywood online at competitive prices and request a fast quote.

FAQ

Can exterior plywood be used indoors?

Yes. It is safe to use indoors, especially in damp or unheated spaces.

How long can exterior plywood be exposed to rain?

Depending on the plywood, short term rain is fine. For extended exposure, the sheet must be sealed to prevent swelling.

How to waterproof exterior plywood?

Apply primer, then add exterior varnish, oil or a weatherproof sealant on all faces and edges. For certain applications this basic method may not be enough, so always check the recommended guidance for the specific job you are doing.

How to paint exterior plywood?

Sand lightly, prime the surface and apply two coats of exterior paint.

Where to buy exterior plywood?

Exterior plywood can be ordered online at Sheet Materials Wholesale with UK stock, trade pricing and fast nationwide delivery.