Deck maintenance used to be straightforward: all were made of wood, and they needed an annual checkup to prevent rotting, splitting or splintering. More choices are available today, such as pressure-treated lumber and composite materials. These newer materials help cut down on regular maintenance.

Pressure-treated lumber resists rot, a consequence of moisture. This dimensional lumber has a greenish hue from the chemical treatment. Most manufacturers recommend against painting pressure-treated decks because paint doesn’t adhere well to treated wood. However, pressure-treated decks should be sealed every year.

Several manufacturers now offer composite decking, a product made of wood fibers and recycled materials such as plastics and rubber. Materials used in composite decks are more expensive than dimensional lumber, but have an important advantage in that the boards can’t rot, split or warp. That makes regular maintenance a snap — simply hose off loose soil. To remove spots, brush on some soapy water and rinse. Save yourself the drudgery of scrubbing deck spots on your hands and knees by getting a long-handled brush.

Seal wooden decks annually to preserve the wood. Suitable sealers are available at hardware stores, home centers and other retail outlets. Perform the following maintenance as needed before sealing the deck:

• Sand any rough spots or splinters out of wooden decks. Wear protective goggles, ear protection and dust mask when using a power sander. A mask is particularly important when sanding pressure-treated decks, whose dust is laden with chemical residues.
  

• Check for loose or warped boards. Most can be re-nailed or re-screwed. (Deck screws provide a bond that’s tighter and more permanent than nails.)
  
  
• Look for rot — it’s always worse than it looks on the surface. Poke around any loose or spongy spots with a screwdriver. If it takes little effort to dig down an inch into the wood, replace the board.
  
  
• Think safety. Check railings to be sure they’re still sturdy. Re-secure screws or nails and replace boards as necessary.
  
  
• Clean away any moss, mildew or film, all consequences of shade and humidity. Brush on a commercial preparation (sold alongside deck sealers) made for this purpose, and rinse.

Sweep any sawdust off the deck, or, if washed, allow it to dry completely, and then apply the sealer. Follow all instructions and safety precautions found on product labeling.