Back Prime Siding

All siding takes on seasonal moisture from sources as diverse as direct rain wicking and vapor diffusion through the wall assembly.

Back prime siding.

Types of paint to use. According to rick crotts my local james hardie representative it s not necessary to back prime any of the company s fiber cement siding products. The back side is better left unpainted. Alkyd oil primers are recommended but one may choose a high quality latex primer as long as it contains stain blockers.

Therefore do not prime the back side of the siding or trim. Back priming consists of applying a coat of primer to the reverse side and edges of boards before installing. Where is the trapped moisture coming from. He says that when panels are primed in the factory some primer ends up on the back of the boards as they pass over the rollers but this isn t a half hearted attempt at priming the backs.

It occurs either when heated or air conditioned air from the house radiates out and meets the cold or hot outside air. Frequently today s homes are wrapped with a vapor barrier i e. For best results fresh siding should be pre primed on all six sides with a stain blocking primer and top coated with 100 percent acrylic latex paint. Back priming helps prevent paint from peeling by reducing the amount of water vapor that passes through the wood.

Not only does back priming prevent rot it prevents bowing cupping. First of all lets explain what is back priming. Dont know what type siding your using but hardie is already primed i think it 39 s primed on both sides i have installed it on my house even if not dont let the exposed side stay un painted too long or you will have to prime it use good paint and it will last a long time even cheap paint will do well on hardie. Back priming natural wood siding helps control rotting mold build up cupping and movement in the wood ultimately giving your siding and your stain finish more longevity.

While back priming has proven to be useful to control tannin staining with some types of solid wood siding trim and some composite sidings lp smartside products are not intended to be back primed. Importance of back priming when installing wood siding.