Subfloor options: OSB vs Particle board

A common question prior to new floor installation is which type of subfloor to use. People often confuse OSB with particle board. OSB is often used as a part of subfloor for carpets, one is used as primary subfloor for hardwood. Let’s take a closer look at both of them.

OSB (Oriented Strand Board)

OSB or oriented strand board is commonly used as a base subfloor because of its stability and affordable price. Oriented strand board is made of chunks of wood, big wood strands and pieces pressed and glued together. Big chunks give each board unique character so every board is quite unique and full of colors. Boards are 8′ by 4′ in size and comes in different thickness, varying from 1/2″ to 1-1/4″. National Wood Flooring Association approves usage of OSB as a subfloor for hardwood flooring with nail-down installation with minimum thickness of 23/32″ and recommended thickness of 7/8″ or 1-1/8″. Proper acclimatization must be done prior to subfloor installation to achieve stable, long-lasting results. In addition to that, underlay paper must be installed between hardwood and OSB. Nowadays, most hardwood manufacturers approve OSB board usage as a proper subfloor for wood flooring.

On the other hand, OSB boards are not suited for tile installation.  Both ceramic and porcelain tile require hardyback or cement board be installed over existing subfloor prior to tile installation. (Note: New Floors Inc does not sell or install Tile)

 Particle Board

Particle board (or Fiberboard) has a different structure – it’s made of small wood chips, particles and wood dust. This interwoven compound is pressed and glued together, but it’s brittle, doesn’t hold nails well and can be easily broken with bare hands. In general, particle boards are used as an addition to regular subfloor for wall- to-wall carpet installation. Particle board comes in different densities, but still softer compared to OSB boards. The most popular types are HDF and MDF – High/Medium Density Fiberboard, with fewer chips and more dust. Particle board and fiber board are more uniform in appearance, and some are painted by the manufacturer for moisture resistance. However, these are NOT approved as a subfloor for hardwood flooring and must be removed prior to hardwood installation.

To summarize, here is a reference for floor materials and subfloors to be used at your house:

Hardwood -> OSB or regular plywood, minimum 23/32″, recommended 7/8″ or 1-1/8″
Tile -> OSB or plywood with layer of cement board or hardiback
Carpet -> OSB or plywood with particle board (optional) for softness.

 

Top Layer Hardwood Carpet Vinyl Ceramic or Porcelain
Fastener Nail, Float or Adhesive Glue or Stretch Glue or Float Adhesive
Moisture
Barrier
Underlay Paper Underlay Paper
SubFloor OSB or Plywood Particle Board,

MDF, HDF

Any Hardyback or
Cement Board