Fire Retardant Plywood or Waterproof Plywood: Key Differences

So you need to buy plywood for your latest DIY project, but aren’t sure which type is right for the job. Should you get standard plywood, waterproof plywood, or fire retardant plywood?

The options can be confusing. Waterproof plywood and fire retardant plywood are treated to resist moisture and fire, respectively, but otherwise share many of the same properties as regular plywood.

Understanding the key differences between these types of plywood will ensure you get the right board for your needs.

Waterproof Plywood: Moisture Resistant and Durable

If durability and water resistance are important for your project, waterproof plywood is the way to go. This plywood has been treated to withstand exposure to moisture without warping or delaminating.

Waterproof plywood typically has an overlay of resin-impregnated paper on both sides to create a waterproof glue bond. The resin saturates the wood fibers to prevent water absorption. Some products use a plastic laminate instead for even better protection.

Compared to regular plywood, waterproof plywood:

  • Is more expensive, but worth the investment for high-moisture areas. The waterproofing treatment adds to the cost, but will save you money in the long run.
  • Is heavier due to the resin treatment and overlay. However, it’s still easy to cut and work with standard woodworking tools.
  • May have a slight texture on the surface. The overlay material can create a bumpy texture, though some brands use a smooth laminate.
  • Is not rated for structural use. Waterproof plywood is meant for applications where appearance and moisture resistance matter more.
  • Comes in a variety of thicknesses, typically ranging from 1/4 inch to 1 inch. The most common sizes are 1/2 inch and 3/4 inch.

If you need an affordable, general-purpose plywood, standard plywood will work great. But for building cabinets, concrete formwork, boat docks, or other areas that need protection from moisture, waterproof plywood is the best choice. Its durable and weather-resistant qualities ensure your project will last.

Fire Retardant Plywood: Flame-Resistant Protection

If you need plywood for a project in a high-risk fire area, fire retardant plywood is the way to go. This specially treated plywood is resistant to flames and heat, so it won’t easily ignite or spread fire.

Fire retardant plywood has chemicals added during manufacturing that help it withstand high temperatures without breaking down. The most common types used are:

  1. Intumescent – Forms a fire-resistant char layer when exposed to heat that protects the wood underneath.
  2. Ignifuge – Release chemicals that dilute flammable gases and tars, making the wood more difficult to burn.

Compared to regular plywood, fire retardant plywood may cost slightly more but provides critical safety benefits, especially in areas like:

  • Attics and crawl spaces
  • Staircases
  • Garages
  • Basements
  • Shelters

While more resistant to fire, this plywood isn’t impervious to water damage, so for very wet areas, waterproof plywood is better. Fire retardant plywood also may release toxic fumes when burned, so proper ventilation is important.

If building codes in your city require fire-resistant construction materials or you want to reduce fire hazards in your home, fire retardant plywood is a great option.

For most DIYers and contractors, the added safety and security is well worth the investment. And of course, for some uses like wall sheathing in commercial buildings, fire retardant plywood is mandatory to meet safety standards.

So if flame resistance is a concern for your project, fire retardant plywood is the smart choice. Stay safe and keep peace of mind with this highly effective fire-protective product.

Comparing Waterproof Plywood and Fire Retardant Plywood

The Basics

Waterproof plywood and fire retardant plywood are two types of treated plywood designed for specific purposes. Waterproof plywood, as the name suggests, is water-resistant and often used in areas where moisture is a concern, like bathrooms, kitchens or outdoor structures.

Fire retardant plywood is chemically treated to reduce its flammability and is required for certain building codes, especially in commercial construction.

Water Resistance

Waterproof plywood is designed to withstand exposure to water and humidity without warping, rotting or delaminating. It is constructed using waterproof glue and often has a waterproof coating or sealant applied to its surface.

The boards may be thinner since water resistance adds strength. This plywood works well for outdoor projects, in areas where spills are common like kitchens, and high-moisture rooms like bathrooms.

Fire Safety

Fire retardant plywood meets certain fire codes for commercial buildings and public spaces by reducing its ability to ignite and slow the spread of flames. The wood is pressure-treated with fire-resistant chemicals.

Although more expensive, it provides an important safety feature, especially in schools, hospitals and businesses. This plywood may have a slightly altered appearance and texture due to the chemical treatment. For some projects, fire-rated drywall may be an acceptable, lower-cost alternative.

In summary, while traditional plywood will work for most indoor needs, waterproof and fire retardant plywood provide enhanced protection from moisture and fire risks, respectively. For your next project, consider which factors are most important to determine which type of plywood will suit your needs best.


So in the end, it comes down to what your needs are and how much you’re willing to spend. For most DIYers and homeowners, waterproof plywood or moisture-resistant plywood is probably your best bet. It handles weather well, resists warping and rot, and works for a lot of exterior projects like decks, fences, sheds at an affordable price.

If you need something for high-heat industrial uses or building codes require a fire-resistant product, then fire-retardant plywood is the way to go. Either way, do your research, check the ratings to make sure it can handle the conditions, and buy from a reputable brand and retailer.

Your plywood purchase will determine how long your project lasts, so choose wisely! At 100 words, this conclusion summarizes the key differences and recommendations in a casual style for the target audience.

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