Hardiplank and many fiber cement siding manufacturers offer siding that comes with primer already applied. However, you may decide that you’d rather prime the siding yourself or you may have changed your mind about your preferred finish after ordering. Luckily, priming fiber cement siding is an easy process.
For this project, it is best to use 100 percent acrylic primer, coupled with an acrylic paint. While oil was once the preferred exterior paint, environmental concerns have made it increasingly difficult to use in many states. A 100 percent acrylic paint and primer will offer you high durability and a large selection f colors to choose from.
Step 1: Begin by looking for any nicks and other imperfections in the Hardiplank. Fill any problem areas with a fiber cement patching compound and a putty knife. Allow any patches to dry according the the manufacturer’s instructions and sand away any rough spots on the patch before trying to prime the siding.
Step 2: Wash the Hardiplank with a garden hose to remove any dirt and other debris. A sponge should be used to scrub away any persistent dirt. Allow the fiber cement boards to dry completely before continuing: this process can take up to five days depending on the weather and the saturation level of the Hardiplank.
Step 3: Apply painter’s tape to any trim or other areas you do not wish to prime. Cover hedges and other outdoor plants with drop cloths to avoid staining the shrubbery.
Step 4: Cut in around the painter’s tape using a 100 percent acrylic primer and a high quality exterior paintbrush.
Step 5: Apply the first coat of primer with a larger exterior paintbrush or a paint sprayer. Both tools will give you great results; it just depends on which you are more comfortable using. Allow the first coat to dry thoroughly before continuing.
Step 6: Apply a second coat of the primer to the fiber cement siding. Allow the primer to dry completely on the Hardiplank before applying your choice of paint.
Step 7: Once the final coat of paint has been applied, remove the painter’s tape and drop cloths.