Outdoor wooden benches are subject to weather conditions such as rain, snow or UV rays. The results of constant weathering is change in the wood's colour and the need for maintenance. Usually, outdoor wooden benches are refinished once a year for the best results and maintenance and to prevent damage from the elements.
Fill a bucket with hot water and about three or four drops of dish soap or a similar mild detergent. Avoid harsh detergents like bleach unless the wood is mildewed or mouldy. If the wood has mould or mildew growth, add about one to two cap fulls of bleach instead.
Rinse the benches with a hose to remove any leaves and built-up dirt that is not stuck on.
Dip the wash rag into the bucket and clean the wood benches. If using bleach or if hands are sensitive, wear gloves before touching the water. Scrub away dirt and grime.
Towel dry the benches to remove excess water. Wait until the wood is completely dry before moving on. This prevents mildew or mould growth under the refinished surface. Check for rough spots, rot or splintering while the wood dries. If there is rot or splintering, the wood or entire bench might require replacement rather than refinishing. Usually, the wood will remain undamaged or have a few minor rough spots.
Sand the surface of the wood bench. Use a fine grit sandpaper, such as 400 or 600 grit, and move it in a back and forth motion along the direction of the wood grain. Avoid moving the sandpaper in the opposite direction of the grain as it can result in damage to the wood. Brush off any dust from sanding.
Select a wood stain if preferred. Wood stains change the colour of the wood and add some protection. If the wood colour is already a preferred colour, staining is not required. When selecting a stain, pick one with UV protection. Paint the stain on the wood along the direction of the wood grain. Allow it to dry.
Select a wood finish for outdoor use. This will have both UV protection and water resistance. Paint it onto the wooden bench along the direction of the grain. Allow it to dry. If preferred or as recommended by the product, add a second layer of finish.
Work on a sunny day for best results.