The outside of a building rarely fails all at once. Small problems build up quietly, and by the time water is coming through a ceiling, the repair is much bigger than it needed to be. Spotting the early signs gives you time to plan the work properly and keep costs under control.

Here are eight signs that a building is ready for external refurbishment.

1. Cracked or hollow render

Hairline cracks in render let water in. In winter that water freezes and expands, pushing the render away from the wall. Tap suspect areas gently. A hollow sound usually means the render has lost its grip and needs cutting out and replacing.

2. Flaking or blistering paint

Paint that is peeling, blistering or chalky has stopped protecting the surface underneath. On stucco and timber, that is when damage speeds up.

3. Damp patches and staining

Dark patches on the walls, green staining below gutters or tide marks on the inside of external walls point to water getting in. The cause is often a leaking gutter, failed pointing or a cracked sill, all of which are best fixed before they spread.

4. Rotten timber and sticking sash windows

Soft timber on sills and frames, or sash windows that stick or rattle, are signs the paint has failed and moisture has got into the wood. Caught early, rotten sections can usually be cut out and repaired rather than replacing the whole window.

5. Blocked or leaking gutters

Plants growing out of gutters, overflowing water in heavy rain and stained brickwork under downpipes all mean the rainwater system is not doing its job. Water pouring down a wall is one of the fastest ways to damage brick and render.

6. Crumbling mortar

If the mortar between bricks is recessed, loose or sandy, the wall is open to water. Repointing with the right mortar, usually lime on older London buildings, keeps the brickwork sound.

7. Stepped cracks in brickwork

Cracks that run diagonally through the mortar in a staircase pattern can point to movement, failing wall ties or lintel problems. These need looking at by someone who knows what they are doing. Structural repair systems such as Helifix crack stitching can often fix the problem without rebuilding the wall.

8. Rusting railings and balconies

Rust on railings, balconies and fire escapes is more than cosmetic. Left alone it weakens the metal and stains the walls below. Treating and repainting is far cheaper than replacing sections.

Why acting early saves money

Most of these problems get worse each winter. A building that needs redecoration and minor repairs this year can need major structural and render work in a few years’ time. Bundling the repairs into one planned project, with one set of scaffolding, is almost always the most cost-effective route.

Not sure what your building needs?

If you have spotted any of these signs, a building survey will show exactly what work is needed and in what order. Block Restoration carries out external refurbishment across London. Get in touch for a quote or call 020 7971 1264.