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 should consider sanding 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.
For potentially dangerous sanding dust, use paper disposable dust collection bags,
and dispose of properly. Use only vacuum capturing sanders, and sweep and wipe clean all surfaces immediately after sanding. Pets and children should not be exposed to sanded surfaces until wood is sealed and protected.
Use caution when working with CCA-treated lumber.
Avoid sawing or sanding, which releases arsenic into the soil and air. If you must sand or saw, do so only outdoors with plenty of ventilation. DO NOT ALLOW CHILDREN or Pets TO ENTER OR STAY IN THE AREA! Wear dust masks, gloves, and protective clothing to decrease exposure to sawdust and wash all work clothes separately before wearing them again. Sand only utilizing proper dust collection and disposal methods. Consumers should follow manufacturer recommendations when handling the wood, including the same precautions that workers should take: wear gloves when handling wood, wear goggles and dust masks when sawing and sanding, always wash hands before eating, and never burn CCA treated wood.
Many products available have their own distinct performance and application characteristics. The product choice for your project should be determined by finding the most suitable product available given your specific project requirements. The premium wood coatings discussed below are all proven solutions 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.
A product we discovered in recent years is One TIME® Wood Protector. It is uniquely long-lasting, offering double the life of anything we have tested. One TIME® is very natural looking compared to many stains available. We believe solvent free One TIME® 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.
One TIME® is simply the longest lasting deck protector we have used and tested after more than 25 years in the business.
If you desire a shiny finished look, consider Sikkens Dek Finish. The deck must have good ventilation, and be at least two feet off the ground. Boards must be sealed on the underside. 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. Again, this product is only 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.
If the decking wood is 2 feet or less off the ground, you should consider only a non-film forming wood protector and sealer like One TIME®. Maintenance for color rejuvenation could be desired at 4-5 years , but wood is well protected for several years.
Another option for low-to-ground decking would be Sikkens SRD. This coating will requires the maintenance coat every year or two in severe exposure, but because it is non film-forming, there is usually never anything to peel, just more frequent refreshing to keep the deck looking new. Some decks will darken with repeated maintenance coats, leading to the need to eventually strip the deck and start again with bare wood.
One TIME® Wood Protector is our best choice for most Hardwood Decking projects.
Sikkens SRD is an oil solution for aged or weathered hardwood . Requires yearly maintenance.
Defy for Hardwoods offers a water-based alternative for covered areas.
Some exotic hardwood exhibits a high oil content which can sometimes interfere with drying and curing of many coatings. We have proven solutions and specific preparation procedures when dealing with exotic woods. Please explore the information here.
We like California Coatings Enduradeck Solid Color Acrylic Floor Coating 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.
For a solid painted look on older deck 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. Will require maintenance more frequently if in direct sun.
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. 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.
For a clear natural finish on porch flooring, consider Waterlox Marine Finish.