Wood Deck Railing Finishing Tips

A deck railing.

Applying a good finish to wood deck railing is vital to preserving its appearance and ensuring that the wood remains strong.

Poor finishing can leave significant gaps where wood rot can flourish, meaning that the wood deck railing can collapse within a few years, or it can leave unattractive marks on the wood itself, making the wood deck railing an eyesore.

While under finishing can result in the wood being unprotected, over finishing can lead to a build up of finish, creating a film-like solid which can result in peeling or cracking.

When to Apply

One of the important details that many people miss is to apply a coat of finish before assembling the wood. This technique ensures that there is limited wood-on-wood contact.

Preventing bare wood from touching reduces the likelihood of wood rotting, so it is a good idea to clean and varnish or finish the wood deck railing before fitting it together. By applying the paint, varnish, or finish before making the wood deck railing, water can be prevented from touching the bare wood. This simple technique also prevents peeling or cracking of the final finish.


It is important to ensure that the wood deck railing finish is applied during good weather conditions. Using water-repellent during cold weather, or applying any finish shortly before rain, can result in the finish being washed off, or marked by water spots.

Bone finishes can be applied in temperatures of as little as 40 degrees Fahrenheit, but water-based finishes should not be used if temperatures are below 50 degrees Fahrenheit.

Apply finish evenly using a brush, ensuring that all points of the wood are covered, but without leaving pools of finish, or tacky spots on the wood.

Avoiding Using Too Much Finish

A wood deck railing that contains too much finish can begin to peel or crack within a year. As decking finish is designed to enter the surface of the wood, an excessive amount of finish can create a sticky goo that does not penetrate the wood.

Over-use of water-repellent finish can make the surface of wood deck railing sticky, waxy, or even slick. Simple stain finishes can also cause sticky or tacky surfaces, which never seem quite dry.

It is easy to avoid this problem by preparing the wood so that it is clean and dry, and ensuring that it is free from mold and mildew. Applying the coat by brush is the best way to manage stairs and wood deck railings, although for larger surfaces it may be easier to use a spray.

When using a spray, remember to back brush the wet finish to even it out and prevent marking. Paint rollers can also be used to apply water-resistant finishes.

Mix the cans together to ensure an even color (also known as "boxing"). Remember to stir often while the finish is being applied. Add the finish to dry wood: a wet-on-wet two-coat application is the best method of ensuring saturation, as this means the wood will soak up both coats.

Prevent the finish from puddling, and wash away excess finish after around 10 minutes. Exposed joints and ends should be covered several times.