Choosing the right material helps prevent water from infiltrating areas around the bathroom sink, toilet, and bathtub, safeguarding against long-term damage. Excess moisture in the subfloor can significantly disrupt the entire bathroom flooring, potentially leading to an expensive and sudden bathroom remodel—something best avoided altogether! In this article, Vinawood will give you information about subfloors such as: features, benefits, types and tips for a better subfloor.
What Is a Bathroom Subfloor?
A subfloor is the structural layer installed directly over floor joists, beneath your bathroom's finished flooring. It provides a stable, level base for tile, vinyl, or wood flooring while supporting the overall load.
For bathrooms, subfloors often require an additional waterproof underlayment, like a cement backer board, to shield plywood or OSB from water damage. This is especially crucial when installing tile, as it helps prevent cracking, uneven surfaces, and moisture seepage.
A waterproofing membrane is commonly applied and typically lasts 10+ years. However, poor installation or low-quality materials can shorten its lifespan. Critical points—such as where floors meet walls—must be sealed properly to prevent leaks.
> Explore further: hdo vs mdo plywood, tongue and groove plywood, walnut plywood, white oak plywood
Which material is best for a bathroom subfloor?
When remodeling your bathroom, the subflooring material is essential. After all, the tremendous levels of moisture in your bathroom is something you have to cope with every day. It's crucial that you select a moisture-resistant material.
OSB and plywood are the two most used materials for subfloors. A sheet of plywood is composed of layers of wood. In each layer, the wood is orientated in opposing orientations.
OSB, often known as chipboard, is a type of sheet material made of layers of flat wood flakes joined by phenolic resins.
The majority of builders and remodeling contractors maintain that plywood is the ideal material for a bathroom subfloor. Additionally, to make sure that moisture doesn't seep into the plywood, it can be made thicker.
However, some builders believe OSB to be a more structurally consistent alternative. In the following section, we'll examine the benefits and drawbacks of each type of subflooring material to help you make an informed decision.
A ¾" tongue-and-groove plywood that interlocks along the edges is a fantastic choice for subflooring. Remember that the joist spacing determines the precise thickness of the subfloor. Each variety also has an enhanced variant available. In other words, you can have either improved OSB or improved plywood.
If the underlying floor joists are spaced 16 inches or less apart, normal 15/32-inch plywood should be utilized; however, if the joists are spaced more apart, thicker 3/4-inch plywood should be used. It’s always a good idea to check with your local building code authorities.
> Discover more: burnt plywood floor, plywood edge banding, plywood garage walls, plywood kitchen cabinets
Pros and cons of bathroom subfloor
Although OSB was first utilized in the 1970s, plywood has been used as a subfloor material since the 1950s. Both of them have a unique set of benefits and drawbacks.
Plywood is stronger and longer-lasting than OSB. It also comes in a variety of finishes, is moisture-resistant, dries quickly, and is overall a great option for an underlayment. Nevertheless, plywood might have weak points that lead to panel voids; also, it is more costly than OSB, not eco-friendly, and has a smaller size range. These are the factors that may hinder plywood from being utilized as a material for subfloors.
Meanwhile, OSB is a more cost-effective, heavier, thicker, and more versatile material than plywood. It also offers a firm, thick surface with good shear strength. There are four things that are disadvantageous: Reduced ability to withstand dampness bulky panels, It is not paintable and prone to expanding around the edges, which is something to think about before adopting OSB as a subfloor material.
Bathroom subfloor cost
Installing a subfloor typically costs between $2.85 and $3.25 per square foot in materials. The entire cost of labor and the cost of materials per square foot range from $8.27 to $16.12.
For a 300-square-foot room, replacing the complete subfloor typically costs between $2,481.75 and $4,836.34.
The project's size and the materials utilized will determine the cost. A four by eight-foot sheet of 3/4-inch-thick subfloor-grade plywood, for instance, costs roughly $21.50, whereas a four by eight-foot OSB sheet measuring 23/32 inches costs roughly $16.50. Comparing that to plywood, each panel is $3 to $5 less expensive.
> Read more: 1/8 inch plywood, 15/32 plywood, 15/32 plywood, 19/32 plywood, 5x10 plywood
Do I need Waterproof the Shower or Entire Bathroom?
Australian Standard 3740-2010 states that waterproofing the floor of the shower recess is the minimum requirement. Since it is in contact with water all the time, it is the most crucial place to waterproof it. Water will eventually infiltrate through tile gaps and grout lines if waterproofing isn't done, which might cause major structural problems.
Even while it might not be necessary to waterproof the entire bathroom floor, doing so is usually recommended for an extra layer of security and to make sure your belongings are safe. The safest and most efficient way to prevent water damage to your home is to waterproof the entire bathroom, especially if your home has a wet room bathroom design, which is a typical feature of many contemporary homes.
There isn't a separate shower enclosure with a shower screen in a wet bathroom. They are well-liked because they eliminate the need for a shower screen, making upkeep simpler. A wet bathroom is not only larger and more open, but it is also simpler for those with mobility impairments to use.
However, more substantial waterproofing will need to be considered because the bathroom floor would be wet rather than just the shower floor and wall.
> Get more details: pine plywood, ac plywood, bamboo plywood, bendable plywood,poplar plywood
FAQs About Bathroom Subfloor
1. What is the best material for a bathroom subfloor?
The best material for a bathroom subfloor is ¾-inch tongue-and-groove plywood due to its strength, water resistance, and stability. OSB is a budget-friendly alternative but less moisture-resistant.
2. Does a bathroom subfloor need to be waterproofed?
Yes, waterproofing is highly recommended—especially in areas around the shower, toilet, and bathtub. A waterproof membrane or backer board helps prevent moisture damage and mold growth.
3. Can I use OSB for a bathroom subfloor?
Yes, OSB can be used, but it should be a high-performance, moisture-resistant grade. However, plywood is still preferred for wet environments due to better durability when exposed to water.
4. How thick should the bathroom subfloor be?
The standard thickness is ¾ inch (or 23/32 inch). If joists are spaced 16 inches apart or less, 15/32 inch may be sufficient. Always check your local building codes.
5. How long does a bathroom subfloor last?
With proper installation and waterproofing, a bathroom subfloor can last 20–30 years or more. Regular inspections and maintenance help extend its lifespan.
6. What causes bathroom subfloor damage?
Common causes include water leaks, poor waterproofing, clogged drains, and improper installation. Over time, this can lead to warping, mold, or floor instability.
7. How much does it cost to replace a bathroom subfloor?
Subfloor replacement costs range from $8 to $16 per square foot including labor. For a 300 sq. ft. space, expect to pay between $2,500 and $4,800 depending on materials.
8. Can I install tile directly on the subfloor?
No. Tile should not be installed directly on plywood or OSB. Use a cement backer board or uncoupling membrane as underlayment to protect the subfloor and prevent cracks.
9. Is tongue-and-groove plywood necessary for a bathroom subfloor?
Tongue-and-groove plywood offers better structural stability by locking panels together, reducing floor movement and squeaks. It is ideal for tile or heavy flooring applications.
Your bathroom is undoubtedly one of the most high-moisture areas of your home, primarily due to the concentration of vapor from the toilet and shower. Therefore, choosing the right flooring material is crucial. A good subfloor will help maintain the health and strength of your bathroom flooring, effectively preventing the growth of mold and mildew. Visit our website Vinawood, you can access the best quality subfloor with the cheapest price.
VINAWOOD - Vietnam Plywood Supplier & Manufacturer
> Learn more:
