| | Sample of Natural Wood Deck Sample of Composite Material Deck (Trex) First, and most important, is the type of wood or material (natural wood or composite material) Generally, wood decks are constructed from redwood, red cedar or southern yellow pine. Because of cost, southern yellow pine that is C.C.A treated is becoming the most popular. This presents one problem, pine is the poorest wood for paint-holding characteristics. Although redwood and red cedar have some minor drawbacks, their paint-holding characteristics are superior to southern yellow pine. FINISHING Since this wood is pressure treated at the mill, its water content may initially be extremely high. One should wait (one week, unless kiln dried - but that's rare) before finishing. On the other side of the coin, the wood should not be exposed longer than one month before finishing, for unprotected wood degrades quickly on the surface, thus reducing its already poor paint-holding characteristics. Don't wait that six month period before applying a finish coat since in that short time, the wood surface will start to degrade. CCA treatment provides wood rot resistance and protection against termite attack, however, is does not provide mildew resistance. CCA also makes pine a little weaker, thus after drying treated wood is more brittle and more prone to cupping, warping and cracking. Finishing Recommendation for CCA - Semi-transparent stains or clear wood preservatives generally perform the best. Heavy bodied finishes, such as paint or solid color stains, tend to sit on the surface and are more prone to peel. If a solid color is desired, three coats of latex are recommended. For decks, one coat of clear or semi-transparent finish will give the best long term results. Do not apply more than one coat of clear or semi-transparent stain, since this could lead to a potential peeling situation. (B) Finishing Redwood or Red Cedar: These woods are ready to finish. Semi-transparent stain or wood preservatives, solid color stains and paints work well. If a latex topcoat is going to be used, it must be primed with an oil based product. This is due to the high tannin content of these woods. Tannin is water soluble and readily "bleeds" through latex films when not oil primed. Like CCA, if a semitransparent stain or clear wood preservative is to be used, limit it to one coat for deck surfaces. Woods that are finished with a stain or paint will always last longer, even Red Cedar or Redwood. Surface Preparation - (New Decks) All surfaces must be clean and dry prior to finishing. Remove dirt, oil and grease by washing with tri-sodium phosphate (TSP) and thoroughly rinse with clean water and let dry. Where mildew is present apply a solution of 1 part household bleach and 3 parts water to kill and remove mildew. Rinse thoroughly and let dry. CAUTION: Do not mix bleach solution with ammonia or detergents containing ammonia. Wear rubber gloves and eye goggles to protect eyes and skin. Protect grass, trees and shrubs. (Previously Stained Decks) Be certain to remove any flaking stain and proceed as with new decks. Do not apply semi-transparent stain over surfaces that have been previously finished with paint or solid color stain. Semi-transparent stains should be used only over bare wood or semi-transparent stained wood of a similar or lighter color. (Weathered Wood) Power washing is an effective method of restoring wood. If power washing is not practical or wood is extremely discolored, application of equal parts water and household bleach will lighten wood color and kill mildew. Follow safety recommendations outlined under "New Decks". |