Caring for a wood garage door finish

Wood door care

Why wood needs a different kind of attention

Wood is a living material even after it is milled, dried and built into a door. It absorbs moisture from the air, swells, then gives it back and shrinks, and a door that does this every season will slowly work its joints, its finish and its hardware. In a hot, humid place the cycle is stronger and more frequent than in a dry climate.

The finish is the door's raincoat. Paint, stain or a clear sealer slows the movement of moisture in and out of the wood, protects the surface from sun and keeps the grain looking even. When that coating thins or cracks, the wood underneath begins to take on water, and problems start at the edges and the end grain first.

A wood door is also heavier than most steel or aluminum doors, and its weight changes the way the springs and opener work. Anything that adds moisture to the panels adds weight as well, which is one of the reasons care is more than appearance. A swollen door that has gained weight can strain a system that was balanced for a drier door.

Our guide to steel, wood and aluminum doors compares the materials side by side if you are still deciding. If you already own a wood door, the steps below will help you keep it looking good and working well.

Know your finish before you do anything

Different finishes call for different care, so begin by working out what is on your door. A solid color paint forms a film that sits on top of the wood and is generally the most protective. A stain with a clear topcoat lets the grain show, and a penetrating oil finish soaks into the surface and needs refreshing more often.

If you are not sure, look closely at a worn spot near the bottom. A film that peels or flakes like skin is paint or a varnish. A finish that fades and turns gray without peeling is more likely a penetrating oil or a thin stain. You can also ask whoever installed or last finished the door.

The answer matters because mixing products can cause trouble. Putting a new film over an old oil, or a water based paint over a failing varnish, may peel within a season. When in doubt, test any new product in a small hidden spot, such as the inside edge of a bottom panel, and wait to see how it behaves before coating the whole door.

If your home belongs to an association, check for rules on color, stain and finish before refinishing. Our list of HOA planning questions before changing a garage door will help you ask the right things so a weekend of work does not turn into a repainting job later.

Edges, end grain and the bottom rail

Wood takes on water most readily through end grain, which is the cut end of a board where the fibers are open like straws. On a garage door the end grain is found on the bottom edge of the lowest panel, along the sides of each section, and at the tops of the rails. If any of these edges is bare, it will soak up moisture and begin to rot sooner than a face of the panel.

The bottom rail is the most exposed part of the door. It sits near the floor, catches splashes from rain and sprinklers, and may rest on damp concrete when the door is closed. A bottom seal that has torn or flattened lets water stay against the wood, so the seal and the finish should be considered together.

When you refinish, take the time to coat the bottom edge and the sides of the door as well as the faces. Many failures start where a finishing job stopped short. A narrow, well coated edge is worth more than a handsome front face with an unprotected underside.

You can read about seal shapes and how they keep moisture off the lowest panel in our guide to types of garage door weatherstripping, and the weatherstripping and insulation service page describes how a technician handles replacement.

• Coat the bottom edge, sides and tops of each section, not just the faces.
• Keep sprinklers from soaking the lowest panel.
• Check that the bottom seal presses evenly and is not torn.
• Wipe standing water from the threshold after heavy rain.
• Look for darkened grain or soft spots along the edges.

Cleaning without damaging the finish

A gentle wash a few times a year keeps dirt, pollen and mildew from settling into the finish. Use a soft cloth or soft brush, mild soap and plenty of clean water. Work from the top down, rinse thoroughly, and avoid soaking the door or letting water run into the joints.

Skip pressure washers and harsh chemicals. A strong jet can lift fibers, strip finish and drive water deep into joints and end grain, while strong cleaners can bleach or darken wood unevenly. Mildew shows up as dark speckles on shaded sections, and a mild cleaner made for exterior wood is the usual choice, tested first in a small spot.

Always let the door dry before closing it up for a long period. Damp wood closed against a damp seal is a recipe for staining and mildew. Keep any water spray away from the opener, the wall control and the electrical outlets.

While you are cleaning, run your hand lightly over the surface. Rough patches, raised grain, chalky areas and places where the finish feels thin are signs that it is time to refinish, and noting them now will make your next step easier.

Mildew and algae deserve a word of their own. In a shaded, damp spot they grow on the finish first, then work into the grain if left alone. Cleaning them off early is far easier than dealing with stained or softened wood later, and a door that gets some morning sun and airflow tends to stay cleaner than one tucked under a dense tree.

Refinishing step by step

Refinishing goes better when planned for a stretch of dry weather with moderate temperatures. In Houston that can mean choosing a cooler, drier part of the year and checking the forecast, since a coat that gets rained on before it cures can blister or turn cloudy. Start by cleaning the door and letting it dry fully.

Next, remove loose or peeling finish with a scraper or sanding block, then sand lightly so the new coat can grip. Fill small cracks or dents with a wood filler made for exterior use, sand the patch smooth and wipe away dust. Prime any bare wood if the product you chose calls for it.

Apply the finish in thin, even coats, following the maker's instructions for drying time and number of coats. Take extra care with edges, the grooves between panels and the area around hinges. Keep the door closed or open in a stable position while you work, and do not lean ladders against the springs, cables or tracks.

Give each coat its full drying time before touching, closing or operating the door. A finish that is still soft can stick to the weatherseal and tear when the door opens, leaving a rough patch you must fix. Patience between coats is the simplest protection you can give the work, and it usually shows in how smooth the final surface feels.

Remember that a wood door is heavy, and removing panels or hardware to finish them is not a casual task. Springs and cables are under high tension and must be left to a trained technician. If a section needs to be taken off the door, call a professional rather than loosening brackets yourself.

Moisture awareness in a humid climate

Houston humidity is the main force acting on a wood door. Warm, damp air keeps the wood moving, and a garage that stays closed for days can trap that moisture inside. Good airflow helps, and our guide to garage heat and ventilation explains how air movement affects the door and everything stored inside.

Watch for signs of swelling. A door that begins to rub against the jamb or track, a section that sticks, or panels that bow slightly outward can all point to moisture. These problems often come and go with the weather, easing in dry months and worsening after long rain.

Do not plane or cut the edges of a swollen door to make it fit without thinking about the dry season. Wood that is trimmed when swollen can leave gaps once it shrinks, and bare cut edges absorb water readily. If you see signs of swelling, our page on a swollen wood garage door explains likely causes and what to tell a technician.

A dehumidifier, a vent or a well sealed door can each help, but none replaces a sound finish. Treat moisture control as one layer of care, and treat the finish as the layer that never takes a day off.

Hardware on a heavy door

Because wood doors are heavier, their hardware works harder. Hinges, rollers and brackets carry more load, and the springs must be matched to the weight of the door. If a wood door has been refinished, repaired or had windows added, its weight may have changed, and the balance of the spring system can change with it.

Windows and decorative glass change the picture. A wood door with window inserts has joints around each opening where water can sneak in, and the glazing seals age with heat and sun. Check those edges when you wash the door, and note any gaps or darkened wood so the technician can look at them with you.

Look at the hinges and fasteners for rust stains, elongated screw holes and cracks around the mounting points. Wood can loosen around a screw after repeated swelling and shrinking, and a loose hinge allows the sections to flex. A technician can reinforce the mounting points or replace hardware when it is needed.

Lubricate hinges and roller stems with a product made for garage doors, following the label, and wipe off excess so it does not stain the wood. Never lubricate or adjust springs, cables or the bottom brackets, because those parts carry high tension. A guide to garage door lubrication outlines the safe parts to treat.

If the door seems heavy to lift by hand with the opener disconnected, or it drifts when stopped partway, the balance may need attention. Read how to test garage door balance and then leave any correction to a trained technician.

Signs a section may need replacing

Wood can often be repaired, but there is a point where a section is past saving. Soft, spongy wood that a screwdriver tip sinks into, black or crumbling rot along the bottom rail, panels that have split across the grain, and joints that have opened wide are all signs that the structure is giving up.

Look for cracks that run through the panel face, a rail that has pulled away from a stile, or fasteners that spin freely because the wood around them is gone. A section with these problems loses strength, can twist as it travels, and may put uneven load on the hinges and the cables.

Think about the whole door as well as the damaged spot. If several sections show rot, if the hardware is worn and the finish is failing everywhere, patching one panel only postpones the next repair. If only the bottom section has taken the abuse and the others are sound, a single replacement can bring the door back into good order. A technician can tell you what the evidence suggests once the door has been inspected.

Replacing one section can be a good choice when the rest of the door is sound, though matching the existing finish and design takes some care. Our page on panel replacement explains how a damaged section is assessed, and the comparison of replacing one panel versus the whole door helps you weigh the choice.

A seasonal routine for a wood door

A simple routine prevents most of the trouble. Before the rainy and storm season, inspect the finish, coat any bare edges, check the bottom seal and clear the threshold. After a storm, wipe the door down, look for new scrapes and note any rubbing or sticking.

In the hottest months, watch for finish that has dried, faded or cracked in direct sun, since that is when the coating is working hardest. In cooler, drier months, do the larger jobs, such as light sanding and refinishing, when the wood is at its most stable.

Keep a short record of what you do and when. The notes in a garage door service log make it easy to see how long a finish has lasted, and the seasonal maintenance checklist gives you a pattern to follow for the whole door.

When to call a professional

Call when the problem moves from the finish to the structure or the lifting system. A door that has become hard to move, scrapes badly on the track, hangs crooked, or makes a loud bang or a new grinding sound should be looked at by a technician. So should any door with visible frayed cables or a gap in the spring.

When you call, describe what you see, where on the door it is, and how it has changed with the weather. The system is inspected on site, the options are discussed before work begins, and the finished work and normal operation are reviewed with you. That conversation is also the time to ask about repairs that fit your finish and your community rules.

Our guide to what owners can check and when to call a pro draws a clear line between safe homeowner checks and work that involves tension, weight or electricity. Keep people and vehicles clear of the door if anything seems wrong.

Questions and answers