Start with a Proper Look Around

Before you reach for a brush, spend a quarter of an hour giving the shed a frank once-over. Most tired sheds are not actually past it — they are simply weathered, and the difference between a shed that looks finished and one that has another decade in it is usually preparation rather than expensive materials.

Work round the outside and press a thumb or the handle of a screwdriver into the timber, especially at the base of the panels, the bottom rail of the door and the corners where water sits. If the wood feels spongy or the tool sinks in easily, that section needs cutting out rather than painting over. Check the roof covering too: felt that has torn, lifted at the edges or gone brittle in the sun will undo a lovely paint job within one wet winter. Look at the door hinges, the hasp and any glazing bars as well, since a shed that does not shut properly lets in the very damp you are trying to keep out.

If the frame is sound and only the surface has gone grey and algae-stained, you are in the good position of a straightforward refresh.

Clean the Timber Back to Something Solid

Paint and wood treatment need a clean, dry surface to grip, and green algae or black mould will simply push the new coating off. A stiff brush and warm soapy water will lift most of it. For heavier growth, a proprietary mould and algae remover applied with a garden sprayer and left to work for the time stated on the bottle is far less effort than scrubbing.

A pressure washer is tempting, and it will strip years of grime in minutes, but keep the nozzle well back and use a fan setting. Too much pressure drives water into the joints, splinters the surface and can blow the softer spring growth out of the boards, leaving a fuzzy finish that soaks up paint like a sponge. If you do use one, let the shed dry for at least two or three days of decent weather before going any further.

Fill a bucket with warm water and a little sugar soap or a dedicated wood cleaner, work from the top down, and rinse well. Pay attention to the underside of the eaves and the bottom edges of the boards, where dirt and moss collect. Once it is dry, sand any rough patches with a medium-grade paper, always following the grain, then dust off. A wipe with a barely damp cloth will take the last of the dust away.

Deal with Small Gaps and Minor Damage

Small defects left alone become big ones, so this stage is worth doing properly. Most of it is inexpensive and takes an afternoon.

• Splits and small holes: use an exterior-grade two-part wood filler. Push it in firmly, overfill slightly, and sand flush once cured. Standard interior filler will crack and fall out within a season.
• Shrunken joints and gaps at the base: a bead of exterior frame sealant, smoothed with a wet finger, keeps driven rain out while allowing a little movement. Do not seal the bottom of the door itself — water needs somewhere to escape.
• Tired glazing: rake out old, crumbling putty and replace it with fresh exterior putty or a glazing sealant. A loose pane rattles and leaks.
• Loose hinges and handles: tighten screws, and where the wood has gone soft around them, drill out and glue in a short length of dowel, then re-screw into solid timber.
• Roof felt: patch small tears with self-adhesive flashing tape, and refix lifted edges with clout nails and a bead of roofing sealant. Replace the whole covering if it is cracking across.

Let any filler or sealant cure fully before painting. Rushing this is the single most common reason a finish fails early.

Choose a Finish That Suits the Timber

There is a real difference between a shed paint and a wood preservative, and picking the right one saves you work later. A microporous exterior paint forms a breathable film, letting trapped moisture escape while keeping rain out — ideal for most overlap and tongue-and-groove sheds. A wood stain or treatment soaks in, shows the grain and is easier to top up, which suits a shed you want to look natural rather than painted.

Water-based products are now very good: they dry quickly, clean up with water and have far less smell, so you can work comfortably in a small garden. Oil-based finishes can be tougher but need longer between coats.

On colour, remember that a dark shed in full sun will get very hot inside, which is unkind to stored tools and paint tins, while a pale finish shows every mark. Mid-tones in green, grey or a soft blue flatter most British gardens and hide a multitude of small imperfections. Buy enough for two full coats — running short halfway through is a classic mistake.

Painting for a Finish That Lasts

Weather is everything here. Aim for a dry day between roughly 10°C and 25°C, avoid direct strong sun and never paint if rain is forecast within four hours. Early morning or late afternoon in summer is often ideal.

Stir the tin thoroughly, then work in a logical order: roof edges and eaves first, then the walls from the top down, then the door and frame last. A 50mm brush for edges and a wider block brush or small roller for flat panels covers ground quickly. Brush the paint out well along the grain rather than laying it on thick — thin coats adhere better and dry without runs. Give the first coat at least the recommended drying time, then apply a second, paying extra attention to the bottom boards, corners and any end grain, which soak up the most.

Mask handles, hinges and any glazing before you start, and lift the door slightly or wedge it open a fraction while painting the frame so it does not stick shut once dry.

Keep It Looking Good in a Small Garden

A freshly painted shed instantly makes a compact garden feel cared for, and a few small touches keep it that way. Fit a cheap plastic gutter and a water butt along one side to stop rain splashing up the boards and to give you free water for pots. Raising the shed on a couple of spare slabs or a timber bearer keeps the base clear of damp soil.

If space is tight, use the walls: a length of galvanised pipe or timber batten fixed horizontally makes tool storage, and hooks along the inside of the door hold brushes, twine and hand tools without eating floor space. Shelves at eye level leave room for the lawnmower beneath.

Finally, book yourself a reminder for next spring. A quick wash and a touch-up on the sun-facing side every couple of years is all it takes to keep the shed looking sharp — and it is far easier than starting again from bare timber.