What Kind of Filler Do You Use to Fill a Hole on Deck Wood?

Preparation

• The hole in the wood deck needs to be free of any dirt, debris or rotting wood. If there is wood left behind that has already started to rot or turn soft, it will continue to do so. This means that sooner, rather than later, you'll be back to make another repair. Place the tip of a wood chisel an inch behind the soft spot or rotted area and strike it with a mallet. Continue chipping away around the wood until the damaged area has been removed.

Wood Putty

• Wood putty is the generic name for wood filler and is either nitrocellulose, acrylic- or gypsum-based. Gypsum is often preferred for small jobs since it comes in powdered form and is mixed for the task at hand. Leftover portions of the other fillers will often dry out in the container. Gypsum also does not contract, like other wood putty, so it adheres to the edges of the hole better. However, gypsum cannot be stained; so unless you paint the deck, the repair will be obvious.

Epoxy

• Epoxy fillers are durable and strong. Like gypsum, they cannot be stained. Epoxies are created by mixing two products together, typically in equal amounts. The chemical reaction makes a stable filler that hardens in several hours. When filling a deeper hole with epoxy, it is best to fill it by sections to allow the product to completely dry at the lower levels. Afterward, it can be sanded, drilled and otherwise treated as wood.

Do-It-Yourself

• Some carpenters believe that homemade wood fill is still the best, according to the "Old House Journal Online." Take a portion of the deck that is not visible or vital to the structure and saw enough wood to get sawdust. Because it is the same wood that is on the deck, the sawdust will match in color. Mix the sawdust with carpenter's white or yellow glue, shellac or hide glue and fill in the hole from bottom to top. After drying, seal it with a layer of the same type of glue.