Most people start thinking about exterior decorating because of how the house looks: the render has gone patchy, the window frames have chalked to a dull grey, the front door no longer matches the rest of the street. Those are fair reasons to pick up the phone. But the outside of a building is a weather barrier before it is a colour scheme, and any exterior job worth paying for begins with an honest assessment of what the existing surfaces are doing — not with a colour card.
London and Surrey housing stock makes that assessment particularly worthwhile. Within a few streets you can find soft Victorian brickwork with lime mortar, 1930s pebbledash, post-war cement render, timber sash windows, uPVC replacements, and modern extensions in different materials joined to all of the above. Each behaves differently in rain, sun and frost, and each fails in its own way. A single coat of masonry paint applied over the lot will look excellent for one summer and then start telling you where the real problems were.
Assessing what you already have
A proper survey walks the whole elevation, ideally in daylight after a spell of wet weather, when problems are easiest to read. These are the things we are looking at.
Render and masonry
Tap testing tells you whether render is still bonded to the wall behind it — a hollow note means it has blown and will take any new coating with it when it eventually lets go. Cracks are graded by how they move and where they run: fine crazing across a panel is usually surface shrinkage and can be bridged with a suitable coating, whereas a stepped crack following the mortar joints is structural and needs a builder's opinion first, not paint. On bare or previously unpainted brickwork it is worth asking whether painting is the right decision at all; once brick is coated, that decision is very difficult to undo.
Timber: fascias, soffits, barge boards and joinery
Timber is where exterior jobs are won or lost. Softwood fascias and barge boards sit under the gutter line and take a constant drip whenever a joint or downpipe is blocked, so they rot from the back and the ends first. We probe suspect areas rather than assume: sound timber resists, softened timber gives. Anything that has gone spongy needs cutting out and replacing before decoration; anything sound but weathered needs the loose material removing, the joints raking out and re-filling, the end grain sealing and knots treating. Bare timber left unprimed for weeks after preparation simply weathers again, so priming follows preparation closely.
Windows and doors
On timber windows the failure points are predictable: the bottom rail, the outer edges of the cill, the putty line and the corners of the frame where water sits. Old, hard, cracked putty lets water behind the glass and the frame decays from within. Perished mastic between frame and masonry does the same. Whether the glazing detail is repaired, renewed or left alone is a judgement made frame by frame. Metal work — railings, gates, downpipes, balconies — needs rust removing back to a sound surface and a suitable metal primer, because a rust spot painted over will bloom back through in a season.
Damp, flaking and coatings that were never right
Flaking paint is a symptom, not the problem. If a coating is peeling in sheets it is usually because it lost adhesion to what is underneath, and the two most common reasons are moisture behind the film and an unsuitable previous coating. Older properties in particular were often painted with something impermeable — a plastic-feeling masonry coating over lime render or soft brick — which traps moisture in the wall. The wall then pushes the coating off from behind, taking a layer of substrate with it. In those cases the honest answer is not another coat: it is removing the failed material and using a breathable, mineral-based system that lets the wall dry outwards.
Persistent damp patches deserve a cause before they get a coating. Blocked or split gutters, a leaking downpipe joint, a cracked cill, defective pointing, missing flashing, ground levels bridging the damp-proof course or plant growth holding water against the wall are all ordinary, fixable causes. Painting over an active leak wastes the work. Green or black growth also needs treating and killing rather than simply washing, or it will come back through the new film.
Weather, season and why timing is not fussiness
Exterior coatings cure chemically, and the British climate sets the terms. Most exterior paints have a minimum application temperature and will not form a proper film below it; many should not be applied when the surface is damp, when rain is expected within a few hours, or when the surface temperature is falling towards the dew point in the late afternoon. Masonry needs to be genuinely dry through, not simply dry to the touch, which after a wet spell can take several days.
In practice, the reliable exterior season in the South East runs from spring through to early autumn, with the best conditions usually in late spring and early September when the light is long, the temperatures are moderate and surfaces are not baking. Working in full summer sun on a south-facing elevation brings its own problems — paint skinning too quickly, brush marks and lap lines setting before the edge can be kept wet — so we work around the sun rather than into it. Booking early matters for the same reason: good weather windows are finite, and rushing an exterior into November rarely rewards anyone.
Access, scaffolding and neighbours
How the work is reached shapes both the programme and the quality of the finish. Ladders and towers are appropriate for limited, low-level work; anything involving sustained work at height, full elevations, chimney stacks or heavy preparation is safer and better done from a scaffold, because a decorator with both hands free and a stable platform simply does better preparation than one balancing on a rung. Where a scaffold is needed, it has to be planned: pavement licences from the local authority where it stands on public footway, agreement with neighbours where it oversails a boundary, allowance for gardens, conservatories, parking bays and side returns, and coordination so the scaffold is up for the work and down promptly afterwards.
Terraced streets in South West London bring their own constraints — restricted parking, narrow rear access, shared party structures — and flats and managed blocks often need permission from a freeholder or managing agent. Raising these at survey stage avoids a scaffold standing idle while paperwork catches up.
How long a properly prepared exterior should last
There is no single number, and anyone who offers one without seeing the building is guessing. Realistically, a well-prepared masonry or render finish will typically hold its appearance for many years, while exterior woodwork and joinery need attention sooner because they move, they take direct water and they sit at the drip line. South and west elevations weather faster than sheltered north-facing ones; a house on an exposed corner ages faster than one mid-terrace. What genuinely extends the life of the work is the preparation underneath, the compatibility of the system with the substrate, correct film build rather than a thin single coat, and simple maintenance afterwards — clearing gutters, cutting plant growth back off the walls and washing down elevations occasionally.
What a professional exterior process looks like
- Survey and specification: walking every elevation, testing render and timber, identifying causes of damp or failure, agreeing what is repaired before anything is decorated.
- Set-up and protection: access arranged, ground, glass, paving, planting and neighbouring property protected, and a plan for keeping the property secure and usable while work proceeds.
- Repair and preparation: failed coatings removed, defective timber cut out and replaced, cracks raked and filled, joints and mastic renewed, growth treated, surfaces washed down and left to dry properly.
- Priming and stabilising: bare timber, metal and any porous or chalking masonry primed or stabilised with the correct product for that substrate, and knots and end grain sealed.
- Finishing: coats applied in the right conditions and the right order, working elevation by elevation with wet edges maintained and drying times respected.
- Handover: a walk round the property together, snagging anything you point out, and a record of the products and colours used so future touch-ups match.
What determines the scope of any exterior project is the condition of the existing surfaces, how much repair and preparation they need, the size and height of the elevations, the coating system chosen, the complexity of the detail and how the work can be accessed safely — all of which are best judged standing in front of the building rather than over the phone. If you are planning work for the coming season, you can read how we approach exterior painting and decorating, see houses we have completed, check that we cover your area of London or Surrey, or request a free tailored quote and we will survey the property and tell you plainly what it needs first. If the interior is on the list too, our piece on how surface preparation decides the finish covers the same principles indoors.