How to Fix Rotten Wood Under the Kitchen Sink

Examine the damage under the sink. If it is slight and the boards are not fully rotted through, replacing the wood may not be necessary. Look for signs of mold damage or a strong smell of mildew. If you do not notice these things, you can try one step before replacing the wood.

Apply wood hardener to the rotted sections under the sink. Wood hardener is used to seal rotted wood and applies a strong protective surface over the wood to prevent future damage. This can be applied with a simple paint brush. Remove everything from underneath the cabinets, apply the wood hardener and give it several hours to dry before replacing the items and using the sink.

Remove the rotten wood. If the wood is too badly damaged to use hardener, you will need to first remove the entire board under the sink. Typically, a single sheet of plywood is used. In older homes, there may be several wooden boards. Use a pry bar and start in one corner. Loosen the bond and move from corner to corner until the wood comes free.

Measure the area for your new wood. You will need to either cut plywood to fit, or order a sheet of plywood that is sized for under your sink. Use a measuring tape and get your length and width measurements for your new board.

Place the new wood under the sink. Center the wood underneath your sink and pound in nails in each of the four corners. If you prefer, you can also use a drill and screws.

Check the pipes under the sink. Once you have new wood, you don't want to ruin it with leaky pipes. Check the pipes to see if there is any water leaking. If there is, call a plumber to have the pipes fixed.