Types of Subfloor Layers for Floor Fitting

What is Subfloor?

Subfloors are the structural layer that lies between the joists and the finished flooring surface. Today, there are three main types of subfloors, each with distinct materials, features, and purposes. Here's an overview of each type:

1. Plywood Subfloor

• Material: Plywood sheets made of several layers of wood veneer glued together.

• Common Thickness: Typically 3/4 inch (19 mm).

• Where Used: Common in residential construction and widely preferred in North America.

• Pros:

  • Strong, durable, and dimensionally stable.

  • Less prone to moisture-related swelling compared to older materials like particle board.

  • Holds nails and screws well.

• Cons:

  • Can warp if exposed to excessive moisture.

  • Slightly more expensive than other subfloor materials.

2. Oriented Strand Board (OSB) Subfloor

• Material: Compressed layers of wood chips or strands bonded with adhesive resins.

• Common Thickness: Usually 3/4 inch (similar to plywood).

• Where Used: Popular for new home construction due to cost efficiency.

• Pros:

  • More affordable than plywood.

  • Uniform and consistent in texture and strength.

  • Good load-bearing capabilities.

• Cons:

  • More susceptible to swelling and damage when exposed to water for extended periods.

  • Can delaminate at edges if not properly protected.

3. Concrete Slab Subfloor

• Material: Poured concrete, often found in homes with slab-on-grade foundations or basements.

• Thickness: Varies (4-6 inches in a standard slab foundation).

• Where Used: Common in basements, ground floors, and homes in areas without frost concerns.

• Pros:

  • Extremely strong and durable.

  • Moisture-resistant if properly sealed.

  • Provides excellent thermal mass for heating and cooling efficiency.

• Cons:

  • Hard and cold underfoot without proper insulation or flooring.

  • Can crack over time if not properly cured or reinforced.

  • Installing other flooring on concrete (e.g., wood) requires vapor barriers or subfloor systems.

Which type is suitable for wooden flooring subfloor installation?