Subflooring is the base floor beneath a finished floor which supports the finished floor and provides the strength and the durability. Well installed subflooring will prevent the creaks and other noises that are often heard in floors.

The subflooring might also be a conduit area for features of the floor, such as heating or air conditioning ducts. In some cases, an electrical panel grid which provides direct overall floor heating will be installed along with the subflooring, usually as an inherent feature of it.

Different Types of Subflooring

Subflooring can be made of a variety of materials, though most subflooring is made of wood. Plywood subflooring is the most common subflooring. Plywood subflooring should be least ¾ inch thick, and laid across the floor joists and nailed or screwed.

Plank subflooring is a stronger type. Plank subflooring is constructed sing 4X8 inch planks, ¾ inch thick, and secured to the floor frame joists by nailing or using deck screws.



Finding and fixing the cause of sweating subflooring is a must to prevent damage to flooring materials above the subfloor, and the growth of mold and mildew in your home. Follow this procedure to stop subfloor sweating.

What You’ll Need:

  • Subfloor moisture barrier
  • Dehumdifier
  • Water pipe insulation
  • Wall insulation
  • Claw hammer
  • Wood nails

Step 1 – Find the Source of the Problem
The subfloor may be sweating due to condensation between it and the concrete base, wall condensation that is seeping into the flooring, or sweating around cold water pipes. Identify the cause of the sweating before attempting repairs and preventive measures.

Step 2 – Repair Wall Condensation
If your subfloor is saturated near walls, lift out the damaged surface flooring and subflooring and install moisture barrier insulation in the walls. Place a moisture barrier under the new subfloor.

Step 3 – Lift Subfloor off the Concrete
Use a product such as DriCore (TM) or Thermal Dry (TM) under your subfloor to channel moisture to weeping tiles or a sump. The dimpled, padded membrane of these moisture barriers lifts your subfloor providing air circulation to evaporate moisture. They also keep the floor warmer, reducing condensation.

Step 4 – Insulate Cold Water Pipes
Wrap a thin layer of polystyrene sheet insulation around all cold water pipes to stop condensation and subfloor sweating.