Decks, Patios, Porches and Docks - Seal Treated Lumber?

I built my deck out of treated lumber. I've had a couple/few people say I should seal it. Isn't one of the reasons for using treated lumber is to avoid/deter rotting from the elements? Should I seal my deck?

Thanks

Treating helps keep termites etc. from devouring your deck, but doesn't really waterproof it or protect it from UV rays.

The question is, do you want a gray, rough looking deck after a season or two, or do you want a smooth good looking deck on which you will be proud to have guests.

After a short time, water will soak into the wood rather than bead up on the surface. In the winter, the water will soak in, freeze, and destroy the wood. The UV rays from the sun will turn the wood gray. A quality sealer, usually with a stain or tint to your liking, is a must do for long term deck preservation.

Thanks for the response.

Some good pressure treated wood also has an extra waterproofer.

This can make it a little more difficult to add extra coatings if needed.

Dick

Sooner or later all PT wood will benifit from stain/paint. While PT left alone will last a lot longer than unpainted regular lumber, at some point it will start to decay. The proper coating will deter the demise of the wood.

IMO it is best to let PT weather for a season and then apply your choice of a stain. Generally the thicker the coating the more protection it gives and the longer it will last. Most clear sealers rarely last for a full year.