Wood Decks-an Introduction

Wood is made up of microscopically small cells.  The cross section of a piece of wood viewed thru a microscope looks just like a honeycomb. No matter where a board is cut from the tree log, it's surface is made up of cut cells, exposed to the surface like little "catch basins."

On an actual wooden deck, even though the cells are treated with an ordinary deck stain or wood preservative, they are still empty and subject to accumulated air-borne dirt and debris, such as carbon dust from automotive traffic (brake-pads, tires, and exhaust emissions), dust, dirt and tree and plant pollen's. Particles larger than the cells will be blown or washed away; smaller particles will fall into the cell and accumulate over time. As the cells fill, we no longer see the color of the wood, but only the color of the combined particles appearing to the viewer as an unattractive "grungy gray". Since vertical surfaces fail to trap as much soil, less attention need be paid to maintaining the natural color of the wood. But on decks, the problem is much greater and even accentuated by the application of "semi-drying" petroleum-based products, such as those with high paraffin oil content.
Through the application of a penetrating finish of high solid content which changes from liquid to solid when exposed to warm air and ultra-violet light (UV), there is little space remaining for the soil to lodge.

Preserving and restoring the natural color of the wood, then, is dependent on:

  • Getting the surface clean.
  • Saturating the wood with a high solid finish.
Subsequent applications, over time, will continue to fill the cells toward the 100% mark. Over-application is to be avoided, as it will result is a "shiner" or glossy appearance. When the cells are virtually filled, there remains little or no space for dirt to lodge, and the wood becomes relatively maintenance-free.

For decks, fences, and siding, etc., penetrating finishes are superior to coatings such as varnish or polyurethane, because they do not crack, peel, or become opaque. The application of penetrating finishes actually strengthens the wood fibers, since the resin residual is stronger than the cellular structure of the wood to which it is applied.

SUPER SEAL is an excellent product for wood decks.