Subfloor options: OSB vs Particle board

A common question prior new floor installation is what type of subfloor to use. It gets confusing when people compare OSB and particle boards as s subfloor. One of them 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

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 that are pressed and glued together. Big chunks give boards a 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 has to be done prior subfloor installation to achieve long-lasting results. In addition to that, underlay paper has to be installed between hardwood and OSB. Nowadays, most of the hardwood manufacturers approve OSB boards usage as a proper subfloor for wood flooring.

In another hand, OSB boards are not suited for tile installation.  Both ceramic and porcelain tile require hardyback or cement board installed over existing subfloor prior to tile installation.

 

 Particle Board

Particle board has different structure – it’s made of small wood chips, particles and wood dust. This compound is also pressed and glued together, but because of its luck of pieces interweaving, it 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 with different density so it is softer comparing to OSB boards. The most popular types are HDF and MDF – High/Medium Density Fiberboard. Fiberboard is basically a form of particle board that has even less chips and more dust. Because of its structure, particle board is quite plain look-wise so you can always tell that it’s particle board. Some particle boards are painted by manufacturer to make it more moisture resistant. Particle boards are prohibited to be used as a subfloor for hardwood flooring and has to be ripped of prior hardwood installation.

 

 

To summarize, here is a dependency of floor material and subfloor 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.