If you have a wood deck or patio this is about the time of year that you realize although originally your deck looked great now the wood has gone grey or the surface is rough from all the weather and activity that the deck has been exposed to. However there are ways to bring it back to looking good and something to be proud of again. First thing is that if you have stained or painted your deck when it was first put down you really are going to want to sand it down. You can stain over previous stain however it will not look so great. You can use sandpaper, or a hand sander to smooth out the boards and take stain and paint. Power washing is a great way to take off paint from deck boards however it wont smooth down the boards and you will need to wait until the wood is dry because staining and painting is not good on wet lumber.
To stain your deck or paint it again make sure that everything is smooth and not staggered or splintered. Then you can apply the stain with a paint roller or a brush. You can you a paint sprayer but with deck stains it can not only get messy but also clogged. Make sure to stain the top and the bottom of the boards if possible, and the railing if it is lumber as well. For repainting you can also apply with a roller or a brush, but the paint sprayer can also be using as long as your spray liberally and evenly otherwise the plain lumber is less forgiving of streaks and uneven paint. You can also just use a clear coat on your boards if you want the natural lumber color however it is likely the boards will bleach out and turn grey even with the clear coat on the boards.
If you have a composite decking than sanding is not something you will want to do, neither is power washing. Both of these things with break down the board and wont let the boards last as long as they normally should. If your composite decking is looking old the first thing to do clean with deck with an Oxalic Acid based cleaner. This will clean off the dirt and any tannins on the boards. If there is any biological growth issues get a bleach based cleaner such as Behr # 62 to clean the decking.
For composite decking you can actually paint and stain this as well much against many people’s beliefs. You do have to make sure of a few things however. You have to make sure that the paint or stain you are using is feasible for composite. If it is than it is most likely to say that on the can. Behr and Cabot both make paints and stains specifically for composite. Just remember if you choose to do this with your deckboards it is likely you will have to do this annually just like with lumber and composite has not been out long to test the affect that paint has on it overtime.
Just remember when repairing your deck or patio to make sure that the wood is still stable and not splintering so bad that it has rotted, at that you will need to replace boards if not the whole deck.