Priming Before Painting

One of the most important rules of thumb in painting is, “always prime raw wood.”  This is especially true for the exterior of your house.  Primer penetrates the surface of the wood, both sealing the wood and providing an anchor upon which the finish paint will adhere.  Without the anchoring effect of the primer, the finish coat will fail.  It may take a few months, or even a few years, but eventually the wood will be exposed and unprotected.  Weather and the elements will invariably damage untreated, exposed wood.  Conversely, when the finish coat painted over the top of primed wood deteriorates, it powders and flakes; the primed wood that is exposed remains protected.  Moreover, the durability of the finish coat greatly increases with the application of primer coat, as it blocks the interaction of wood borne and waterborne chemicals, such as tannin, calcium and salts, due to exposure to the elements. 

                Interior priming can also be valuable.  Raw wood, such as trim and cabinets, also benefits from priming due to the anchoring effect.  Raw drywall and fresh drywall texture also need priming.  If you do not prime new drywall/texture, you will not produce the build or luster desired of paints with any kind of sheen.  Flat paints will also suffer, due to the lack of hide that primers provide.  As a rule, if what you are painting has never been painted, then you should prime it before painting it.

                For exteriors, you may need to buy a stain blocking primer, depending on the condition of the wood.  In addition, it is recommended that you prime any composite siding, such as Hardie Plank.  For interiors, most products will work fine, unless you have water damage/stains, in which case you will need a stain blocking primer.

For small areas you can use a brush and or roller to apply the primer. For larger areas, you can use a brush and roller or you can use a Paint Spray Rig. If you choose to use the paint spray rig wait until you are prepped to start spraying, then spray prime the needed areas before you paint them.  Note:  Brushes leave brush marks and rollers leave orange peel.  If your desire is to produce the smoothest finish possible, you may want to spray both the primer and finish.

I hope this tip was useful and helps you produce a beautiful and professional finish on your home. Remember, a fresh coat of paint on the exterior of your home adds a great deal to the curb appeal and value of your home.