All wooden doors require attention on a regular basis. The cause is Ultra‑Violet radiation (UV). Ultra‑Violet radiation’s high‑energy waves cause deterioration in any surface they strike.
UV radiation is the portion of sunlight that causes sunburn in people. So you can imagine the damage UV causes your door, as the door is continuously exposed to this radiation. It takes only a couple of hours for a person to get seriously sunburned even on a cloudy day. Depending on the season, your door can be exposed to that same UV radiation for long periods.
It does not matter if the UV rays are direct or reflected. Consider how a museum protects its valuable paintings and documents. These items are displayed in darkened rooms with specialized lighting and behind UV‑filtering glass. UV rays are so damaging that museums must protect against reflected UV rays.
UV rays are so damaging that museums must protect their treasures against even reflected light.
How the layers break down
The UV rays strike the outer layer of finish and cause chemical and physical changes. The finish begins to yellow and develops micro‑cracks in its surface. The outer layer filters out a large portion of the UV rays, but some make it through to the second layer. A smaller amount reaches the third layer, and some rays even reach the stain. The effect is the same on the lower layers as on the surface — the finish yellows and cracks, and the stain fades in color. It just occurs at a slower rate.
As time goes on, the outer layer loses its ability to filter UV rays, and a larger percentage reach the inner layers. This increases the rate of deterioration. Eventually the innermost layer of finish begins to also break down, by cracking and detaching, exposing the raw wood of the door to increasing damage.
Water, mold, and mildew make it worse
Compounding problems are water (rain & sprinklers), mold, and mildew. Once the finish layers have developed cracks, moisture gets into the cracks and behind the finish. As outside temperatures change, the water expands and contracts, speeding up the deterioration.
The cracks also allow molds and mildews to penetrate the surface of the finish rather than just lying on top of it. If they reach the actual wood surface, they grow into the pores of the wood and can cause permanent discoloration.
The good news
Our Maintenance Service is designed for the purpose of keeping your door sealed and Happy. It consists of a gentle sanding by hand, a thorough cleaning of the door and a marine spar finish on the surface to seal and protect the door. We offer you the maintenance program to extend the life of the finish to its maximum and keep the door looking good for years to come. Contact us for details.
