Installing Oriented Strand Board Exterior Trim


Oriented strand board, or OSB board, is a particle board type of plywood. This type of wood is impregnated with resin to give it a little more strength. It is commonly used for flooring, but, it can also be used as exterior trim. There are some things to remember.

Not Water Proof

If you are going to use oriented strand board as an exterior trim then you will want to make sure it is sealed, and protected against the weather. The directions that come with the board warn against any type of water coming in contact with it.

Mitre Cuts Need a Gap

Finished exterior trim gives your house a certain appeal. When you use the oriented strand board for exterior trim you can not cut the mitre cuts as you normally would. You must leave at least a 3/16 inch gap in between cuts for constant expansion and swelling if wet.

Predrill for Finish Nails

When you install the OSB take the extra time to predrill the holes for the nails. This makes the installation a little longer but it is worth not causing any cracks near the edge.


Painting oriental strand board is easier than most trim. It is pre-primed so you only have to add one coat to the wood for a good coating of paint.