Paint a Front Door With Dulux Weathershield in 6 Steps for 5-Year Protection

What the 5-year guarantee depends on

Dulux ties the Weathershield exterior guarantee to the way the coating is applied. The instructions require a primed surface, the stated spreading rate of roughly 13 square metres per litre per coat, and at least two finish coats. A standard external door is around 1.9 metres by 0.8 metres, which puts both faces plus the edges near 3.5 square metres. Two coats bring the paint use to about half a litre, so a 1-litre tin gives room for brushing losses and edges.

The substrate condition matters just as much as the paint quantity. Bare, weathered, or previously flaking timber that has not been cut back to a sound surface falls outside the protection claim. The same applies to paint put on below 8 degrees Celsius or onto a damp face. Current Weathershield is a water-based acrylic, so it dries faster than the old solvent line while becoming more sensitive to moisture in the film during the first hours. The 5-year figure depends on a sound build-up underneath the finish coat, and door failures usually begin in that base layer.

Step 1: Read the timber before sanding

Press a thumbnail into the wood near the bottom rail. A soft dent points to softened timber, so hardener or filler has to come before any coating. Run your hand over the old finish as well. Chalky residue on your palm shows oxidation, which needs a full key across the surface rather than a quick scuff. South-facing and west-facing doors weather unevenly, with the lower third often in worse condition than the panels at eye level.

Use a cheap pin-type moisture meter if one is available. Timber above roughly 18 percent moisture content can hold water under an acrylic film and blister it within a season. After rain, give the door two dry days before painting. That one moisture reading explains many peeling front doors, and the fix is simply waiting long enough for the wood to dry.

Step 2: Strip, fill, sand, and clean

This stage carries most of the guarantee risk, and it is usually where weekend jobs lose time. Scrape loose or flaking paint back to a firm edge with a stiff blade. Sound glossy paint can stay, provided it is abraded with 120-grit aluminium oxide paper so the new film can grip. Feather scraped patches into the surrounding coating, because a hard boundary between bare timber and old paint will show through the topcoat as a ridge.

Fill splits and gouges with a flexible exterior wood filler. Ronseal High Performance and similar two-part fillers cure hard enough to sand within 30 minutes and cope with the seasonal movement caused by humidity swings. Interior-grade fillers shrink and crack at the first cold snap, so they are a poor match for the face of a front door.

Softwood knots can bleed resin into pale topcoats. Seal them with knotting solution before priming, otherwise the stain can travel through each later coat. After the filler has cured, sand the whole face with 180-grit until the sheen is uniformly matt. The finished surface should feel keyed, level, and clean, with filler flush to the surrounding timber and sanding dust removed.

Vacuum the door and the nearby frame. Then wipe the surface with a cloth dampened in white spirit or sugar soap solution to remove grease and handprints, especially around the handle. Years of pushing a door open leave skin oils exactly where adhesion is most exposed. Let the surface dry fully before primer goes on, because trapped cleaner under primer causes the same adhesion trouble as grease.

If some hardware has to stay in place, mask the hinges, letterplate, and handle with low-tack tape at this point. Painting to a clean taped edge is faster than cutting in freehand around a brass knocker. It also helps keep the guarantee-relevant film thickness even right up to the metalwork.

Step 3: Prime the areas that need grip

Bare timber, filler, and sealed knots need primer before Weathershield is applied. Dulux Weathershield Exterior Preservative Primer works, and so does a general-purpose acrylic wood primer. At 15 to 20 degrees Celsius, these primers are usually touch-dry and ready for another coat after two to four hours, although the tin instructions should set the pace for the day.

Patch-priming is acceptable when the existing paint is sound across most of the door. Raw wood left without primer absorbs unevenly, leaves the topcoat sitting on an unstable base, and can lead to sheets of film lifting later. Apply primer thinly and evenly. A heavy primer coat slows the recoat window and does not improve adhesion. One well-brushed coat over bare timber and filler is enough to seal the surface and give the topcoat a consistent colour base.

Step 4: Brush a panelled door in the right order

A six-panel door is easier to control if the small areas are coated first. Paint the mouldings and recessed panels before the surrounding rails, working the brush into the internal corners while those rails are still dry. Move next to the horizontal rails, then the vertical stiles, and finish with the outer edge of the door. This order lets each broad section be laid off in one direction without dragging a loaded brush through paint that has already started to skin.

Weathershield starts setting within minutes in warm air, so laying off matters. Load a 50mm synthetic-filament brush, spread the paint across the panel, and make one light final pass. Use top-to-bottom strokes on stiles and left-to-right strokes on rails. Once a patch has begun to tack, leave it alone. Going back into it pulls the surface and leaves raised brush ropes that remain visible after curing.

Keep the wet edge moving. In direct sun, a door face can flash off so quickly that the starting area is touch-dry before the opposite side is finished. Shift the work to the shaded part of the day if necessary, or complete one full coat in a single uninterrupted pass. Two thin coats applied this way last much better than one thick coat. Thick acrylic skins over on the surface while the underlayer stays soft, and that soft layer is where blistering starts.

Step 5: Coat count and drying time

Dulux requires a minimum of two Weathershield topcoats over primer for the exterior guarantee. Bare or heavily weathered timber can justify a third coat. Current water-based Weathershield has a recoat interval of around two to four hours at 20 degrees Celsius, with longer waits in cold or humid conditions.

Timing changes the way the film cures. A second coat applied too early traps solvent and water inside the film. Waiting a day or two remains acceptable, although it does not add performance compared with the stated window. Judge the coating by the conditions on the door, not by the clock alone.

At 10 degrees Celsius, the same coat that dries in two hours at 20 degrees may need most of a day. The 8 degree guarantee floor is firm, because the acrylic cannot coalesce into a continuous film below that point. A coat brushed on at dusk in autumn may look dry after sunset while curing badly underneath, and that weak layer is often the first one to fail.

Step 6: When to use the door again

Weathershield can be touch-dry within a couple of hours, while full hardness takes days. Leave the door open or propped so the latch face does not stick to the frame, and avoid closing it firmly until the film has cured for at least 24 hours in mild weather.

The hidden edges decide a lot

The top edge and bottom edge of a door are major entry points for water, and they are the faces most often left uncoated because they are out of sight. Exposed end grain on the bottom rail draws moisture quickly into the wood. An unpainted lower edge can rot a door from underneath while the visible faces still look sound. If possible, lift the door off its hinges. If that is impractical, slide a loaded brush along the bottom edge and give it the same two coats as the faces.

The hinge edge also needs attention because grime collects there and sanding is often awkward around the hinges. When hinges have been masked in place, pull the tape while the final coat is still slightly soft so the edge lifts cleanly before the paint cures hard enough to tear.

Check the threshold gap after the paint has built up. A door painted to a film thickness that closes the clearance against the frame will bind in damp weather when the timber swells, and friction can strip fresh paint off the leading edge within weeks. A two to three millimetre gap with visible daylight through it keeps the coating away from that seasonal rubbing.

Five years can be realistic on the main faces. The unresolved weak point is underneath, where the bottom rail has to stay dry enough for any coating to keep its hold.