We want to repair or columns outside the front of our house.. We want to know if we can use mdf...right now they are made of pine and are painted white. Does anyone know if MDF can be used outside.

First, this question should be posted on one of the other forum sections, this section is targeted for handicapped accessibility questions.

Second, MDF stands for Medium Density Fiberboard which is a composite of wood particles in a synthetic resin binder. The density refers to the weight per cubic foot which in this case is 40-50 lbs.

Most particle board products are not recommended for exterior use with the exception of Moisture Resistant MDF. However, caution still should be used since no particle board product is recommended for use in locations with humidity swings greater than 30% to 40%. Most outdoor locations exceed this. Also, fiberboard does not perform well when exposed to direct water which is likely at the base of a column.

You might consider using a cement board product such as "Hardie-board" which is available in 5/16" x 48" x 96" sheets. Using cement board will require a special blade for your circular saw. Special attention to fastening methods is recommended.

This question should be posted on one of the other forum sections such as carpentry. This section mainly concerns handicapped accessibility.

MFD stands for Medium Density Fiberboard which is a material formed from wood particles in a synthetic resin binder. Medium density refers to the weight of the material which, in this case, is 40 to 50 lbs per cubic foot. Although some particle boards are "moisture resistant" they are not recommended for exterior use especially at a column with exposure to direct rain. Particle board is not recommended in applications where the moisture levels have a variation of more than 30% which is the case in most exterior locations.

Consider using a cement board product such as "Hardie-board" which is available in 5/16" x 48" x 96" sheets. Cement board is very water resistant, tough, dimensionally stable, and holds paint well. Drawbacks are that it is harder to cut (you must buy a special circular saw blade), long/narrow strips are somewhat brittle, and it requires more care in nailing/screwing.