Decks and Porch Flooring
Keeping decks well protected is a big challenge. The wood is in a horizontal position, full of nail holes allowing water to seep into the wood where it will swell, shrink and warp the wood and stress your stain or coating system. Wood that is inaccessible , such as end grain, can't be properly sealed once the deck is already constructed. Most times, furniture scrapes the surface, people and dogs track grit and mud on it, and Mother Nature takes a toll.
The following discussion explains reasons we must sand wood for best results with any stain or finish when wood has been allowed to weather in the elements, or if a previously applied coating has failed. Many times, it is highly beneficial to sand even new wood for a variety of reasons.
SANDING DECK SURFACE
Sanding opens the pores of wood to accept stain, and also removes loose or deteriorated wood fiber that generally leads to premature coating failure and poor results. Sanding can also be utilized to blend or remove remaining stain after the deck stripping process. Even NEW Wood usually needs sanded due to "mill-glaze" resulting from the Planing Process , which compresses wood fiber, and POLISHES new wood making coating penetration virtually impossible. Wood that has weathered unprotected while drying over the first few months after installation should be sanded as well to remove weathered surface.
DECK COATINGS
Many products available have their own distinct appearance, performance, and application characteristics. The premium wood coatings discussed below are all proven solutions we choose for various specific conditions. Trans Oxide pigments provide the highest level of ultraviolet resistance, and impart a very natural look to the wood. Most of the coating choices outlined below utilize this premium pigment type. New wood should be sanded to remove possible mill glaze, or to remove grayed wood fiber if deck has weathered during the drying process. Sanding will always increase the adhesion and performance of your coating system.
Natural Finish
A product we discovered in recent years is OneTIME Wood Protector. It is uniquely long-lasting, and is very natural looking compared to many stains available. We believe solvent free OneTIME Wood Protector is good choice with respect to environmental issues and ease of maintenance. This is a great choice for docks and severe exposure. It offers beautiful protection with extended easy maintenance procedures. The most unique characteristic about the OneTIME is that it is virtually impossible to get lap marks or drip marks due to the unique way the product works on wood. We have coated 1/2 way across a board one day, then coat the second half the next day, and amazingly -NO LAP MARKS.
If you desire a varnish-like shiny finish, and ventilation is good, deck is at least two feet off the ground, and boards can be sealed on the underside, you could consider a thicker film-forming coating like Sikkens Dek Finish . This is a two coat brush applied alkyd protective translucent finish system for exterior wood decking. On properly prepared wood surfaces, this coating gives practically a look of furniture, imparting a varnish like shine while beautifully accentuating grain and color of the wood. This system requires a maintenance coat about every 3 years if in full sun. You need to have the pores of the wood grain open for proper anchoring of the sealer. The first coat preparation is the most important factor in longevity of the entire coating system. This product is suitable if the bottom side of the deck is sealed, and is at least 2 feet off the ground.
For a water-based Satin finish consider Structures Nature One. Structures is a great alternative to oil based varnishes, it looks and performs great, and is environmentally friendly.
If the decking wood is 2 feet or less off the ground, you should consider only a non-film forming wood sealer like OneTime. Maintenance for color rejuvenation is generally around 3-4 years, but wood is well protected for several years.
Hardwood Decking
One TIME is a great solvent free protector offering long lasting protection on hardwood decks. The UV cure is a great feature, since new exotic hardwood exhibits a high oil content which can sometimes interfere with drying and curing of many coatings.
Read more: Staining Ipe, Mahogany, and other Exotic Hardwood Decks
(See Video One TIME for Hardwood).
If an oil finish is required, Sikkens SRD is a proven solution for most mahogany and other dense hardwoods.
We have proven solutions and specific preparation procedures when dealing with exotic woods. Please contact us for specific project advice.
Porch and Deck Flooring
Porch and deck floors are sometimes difficult surfaces to protect, as the softer a coating is, the easier it wears off, but the better it tolerates moisture transfer and wood expansion cycles. Conversely, the harder wearing a coating, the less able it is to handle expansion and contraction of the wood, so most coating choices represent tradeoffs to consider.
It is very important to seal the underside of a deck or porch floor. The best method is to seal the bottom side of boards and end grain cuts before construction. If wood is near the ground, and the sun beats down on the top surface, moisture is drawn from the cool ground underneath up through the bottom side of the boards. This causes expansion and contraction of the wood, leads to cupping of the boards, and greatly reduces the long-term performance of any coating.
The product choice for your project should be determined by finding the most suitable product available given your specific project requirements.
Solid Color
For a solid painted look on exterior porch floors, you could consider Sikkens Rubbol DEK, which is the only flexible, breathable oil based wood floor coating (not a paint) that we are aware of. It looks like paint, but performs like a stain--no film to peel. It is breathable and flexible when applied to bare wood. For an acrylic solid stain, we prefer California Coatings Enduradeck Acrylic Floor Stain System for many projects. The Acrylic makeup gives this coating excellent satin sheen and color retention.. It offers excellent adhesion to properly prepared surfaces that have been previously coated. Enduradeck is flexible and breathable and is a great choice to consider when coating exterior wood decks and flooring.
Previously Coated Wood
Regardless of your coating choice, it will still be best to try to strip or sand any old, failed coating. After using strippers, many times wood is "fuzzed" and should be sanded using 3x Sand Paper 80 grit following the stripping process.
3x Sand Paper is also designed for coating removal. The paper really does make a difference. Most floor coatings will recommend 80g or 60g bare wood sand, but it depends on the coating you choose. We use a Dust Free Palm Sander . If you have sharp corners on boards that could be slightly sanded round, that would be helpful. We always do a final brush vacuum prior to coating application, and actually wipe the surface to insure no dust can interfere with coating absorption and adhesion.
Visit us at Timbercoatings.net for project assistance BEFORE you build your deck. Wood must be back and end-grain coated for optimal performance.
All the best, until the next.
Doug
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