How to Finish Fiber Cement Board

Lead Image for How to Finish Fiber Cement Board
  • 2-4 hours
  • Beginner
  • 100-750
What You'll Need
Pressure washer
Acrylic fiber cement coating
4 inch paint brush

Fiber cement board is a highly popular building material thanks to its high durability. It is made from a highly effective mix of cement, wood, and sand making it virtually immune to rot. The fiber cement board is often manufactured to have an artificial wood grain so that when finished, the surface looks very similar to real wood. There are various important techniques and preparations that you need to take note of when applying a finish to fiber cement board so that you can enjoy proper results. You should also use coatings of products that are specifically designed for applying to fiber cement boards.

Prepare the Area

Before you start working on the surface of the walls, trim back any vegetation around the base of the boards as much as possible. This will allow you easier access to the wall as well as help prevent the risk of contamination of the finished product.

Prepare the Board

If the board has just been installed, then there should not be much work involved in preparing it. Be sure that any dirt is removed from it before applying any finish. To do this, first, check for any oily spots on the board. These need to be removed using a proper degreasing agent applied with a coarse scrubbing brush. Once you are satisfied that any greasy marks have been removed from the board, continue cleaning the wall by using a high-pressure hose. Thoroughly spray down the surface and scrub off any other dirt that you find. Once you have washed down and rinsed the entire surface, it will then need to be left to dry. Leaving it for a full day is ideal.

Apply the Coating

Before applying the cement board coating, be sure to cover the areas nearby. The chemicals on the cement coating that you will be using can damage surrounding plants and other items. Cover everything using tarpaulin or drop cloths before you start.

When the surrounding area is protected, open up the cement coating container. This will need thorough stirring for several minutes. Once you have stirred the coating, pour a couple of gallons of it into a large five-gallon bucket. Apply this cement coating to the surface making sure that you get a thorough, even coat, covering every area of the fiber cement board. The best way to do this, and the way most professional tradesmen do it, is by using a roller with an extending pole. This way, you may not even need to climb up a ladder. Roll on the coating vertically and smooth out the surface as you go while checking for any drips and eliminating them as soon as you see them. When finished, leave the surface to dry for a day.