Deck finishing is much more than just stain

Hey there, time traveller!
This article was published 04/05/2008 (6333 days ago), so information in it may no longer be current.

Every summer, I hear from homeowners looking for advice about finishing their new wooden deck. And every summer, I wish I could’ve talked to these folks a few months earlier. That’s because finishing a deck really isn’t about finishing a deck. It’s also about critical design and construction details required to create a deck that stays beautiful for a long time.

This goal can’t be achieved as an afterthought while standing in a hardware store aisle deciding which deck stain to buy. No, to achieve a durable deck you must start at the beginning with sound construction strategies and a field-tested finishing approach.

The first thing to understand is that achieving a durable deck finish doesn’t happen easily. The effects of water, sunshine and gritty foot traffic makes the deck-finishing challenge difficult. That’s why so many new decks look grey and lifeless after a year or two.

All deck finishes are especially vulnerable on 90-degree edges. Everywhere that a sharp corner exists, the potential for early finish failure is high. In fact, it’s guaranteed. That’s because finishing liquids become very thinly spread on corners as you brush them on. This is also why it pays to get rid of sharp corners during construction.

The first and most obvious involves easing corners and edges using a router spinning with something called a roundover or chamfer bit. As the name suggests, this tool converts sharp corners into gently curved or angled edges. If you’re building your deck, simply include a router in the tools you gather for the job. If you’re hiring a pro, ask for rounded or chamferred details, ignoring the very probable comments about “not normally doing it this way.”

Another construction feature that makes finishes fail too soon is the traditional practice of fastening deck boards from the top down with screws. Every place a screw head divets the surface of outdoor wood, it creates a brand-new corner where the finish will invariably be weak and prone to early decay. This is one reason I like hidden deck board fasteners. The other reason is superior appearance. The smooth, hole-free surface looks so much better, even without considering how much longer it’s going to stay that way.

Every newly-built wooden deck seems to call out for finishing. That’s why so many homeowners are too quick to get busy with a brush, setting themselves up for premature finish failure. The fact is, many deck finishing products fail quickly, even when applied over a properly prepared surface. Then there’s the issue of hidden wood moisture and its effect on finishes.

Before you build any deck, be sure you’re using nails, screws and bolts that are hot-dipped galvanized or stainless steel. Too many decks are built with shiny, corrosion-prone electroplated fasteners that are destined to stain the surrounding wood and fail prematurely.

For critical information on specific deck finishing products and strategies that have proven themselves in the field, send me an e-mail at deckfinishing@stevemaxwell.ca.

Steve Maxwell is technical editor of Canadian Home Workshop magazine.

— Canwest News Service