Exterior cleaning is one of those maintenance items that's easy to defer — until something goes wrong. Here are the five most reliable signs your building needs attention now, not next year.
1. Visible black streaks or biological growth
Dark vertical streaks under window sills, gutters or copings are algae, lichen and pollution deposits. Left untreated they stain masonry permanently and etch into rendered surfaces.
2. Blocked or overflowing gutters
Water spilling over gutter edges during rain means moss and silt have built up. Ignored, this causes fascia rot, damp internal walls and — in extreme cases — collapsed gutter runs.
3. Cladding or render looks tired and dull
Uniform dulling of coloured cladding, painted render or brick is atmospheric pollution deposit. A professional soft-wash or steam clean restores 90%+ of original colour without abrasion.
4. Tenants or customers commenting
If tenants raise the appearance of the exterior in surveys or reviews, you're already behind. Exterior cleanliness is a leading indicator of perceived building quality and directly affects lease renewals.
5. It's been more than 2 years
As a rule of thumb: London commercial buildings should have a full exterior clean every 2–3 years. Buildings on main roads or near industrial areas need it every 12–18 months.
What a deep exterior clean covers
A professional programme typically includes: gutter and fascia clean-out, soft-wash or steam cleaning of cladding and render, algae and lichen treatment, exterior windows via Reach & Wash, and inspection for missing pointing or damaged flashings. On most London commercial buildings this takes 1–3 days depending on height and access.