For all aspects of roofing, building and landscaping work, call the team at Green Building London Ltd today — professional, caring and high-quality workmanship, guaranteed.
Damp or mould this winter? We fix the root problem, not just the surface →Black mould in the bathroom, a damp patch on the ceiling, plaster blowing above the skirting? Winter is when these problems show up, and paint only hides them for a while. We find the root problem and fix it, then repair the wall, to stop it happening again.
Cleaning a wall won't stop it coming back. As government guidance puts it, "simply removing surface mould will not prevent the damp and mould from reappearing."
Paint or a mould spray can make a wall look better for a while. If water is still getting in, the stain and the mould come back. So the surface is the last thing we do, not the first.
The cause is still there, so the problem returns.
The source is dealt with, which is what stops it happening again.
The fix is often on the other side of the wall, so we work inside and outside the house.
The right fix depends on the cause, so it helps to know which of the three common types you're looking at.
Signs: wet windows in the morning, black spots in corners and behind furniture, a musty smell. This is the most common form of damp, and it peaks in winter.
The root fix: extractor fans and better ventilation in kitchens and bathrooms so moisture can escape, then mould removal. Cleaning alone won't last.
Signs: flaking paint and blown plaster low on ground-floor walls, usually in older properties. It is often misdiagnosed, so it needs checking properly.
The root fix: a new damp proof course where the old one has failed and clearing anything that bridges it, such as a raised patio. Re-plastering comes after that.
Signs: patches on ceilings and walls that spread or darken after rain, often below a window sill, a roof leak or an overflowing gutter.
The root fix: repair whatever is letting the water in, such as the roof, gutters, render or pointing. Re-plastering comes once the wall has dried.
Call us, or send a few photos on WhatsApp. Tell us where the damp is and when you first noticed it.
We check the walls, render, roof, gutters and ventilation, then give you a free, no-obligation quote.
We repair the root problem first. Only then do we clear the mould and re-plaster where needed, leaving the room ready to decorate.
Damp and mould mainly affect the airways and lungs, and can also affect the eyes and skin. Government guidance says children and young people, older people, pregnant women and people with existing health conditions or weakened immune systems are among those most at risk. If you're worried about symptoms, speak to your GP.
Awaab's Law has applied to social housing in England since 27 October 2025, and the Renters' Rights Act 2025 gives the government the power to extend it to private rented homes. If a tenant has reported damp or mould, send us the details and we'll quote to fix the cause, not just repaint over it.
It will only hide it for a while. Stain blockers and anti-mould paint cover the mark, but if moisture is still getting into the wall, the stain or the mould comes back. The cause needs fixing and the wall needs to dry before it is redecorated.
With the windows shut and the heating on, moisture from showers, cooking and drying laundry has nowhere to go. It settles on the coldest parts of the house, such as window frames, corners and the walls behind wardrobes. Homes that are hard to keep warm are more prone to it, and heavy rain finds any failed gutter, cracked pointing or damaged roof.
Usually, if it is a very small patch on a hard surface. Government guidance says to use a mould and mildew product rather than bleach, wear a mask, gloves and goggles, keep the door shut and the window open, and let the surface dry completely. It says larger areas should only be dealt with by qualified professionals. Mouldy carpets and soft furnishings may have to be thrown away.
It will if the cause is still there. Government guidance is clear that simply removing surface mould will not prevent the damp and mould from reappearing. That is why we fix the root problem first, whether that is a leak, failed render, a failed damp proof course or poor ventilation, and only then clear the mould and repair the wall.
Rising damp is usually found in older properties and shows low on ground-floor walls, but it is often misdiagnosed. Government guidance says chemical testing is the most appropriate way of confirming it, so ask how it was diagnosed before paying for a new damp proof course.
It depends on the cause and how much of the wall is affected. Clearing and repairing a gutter is a small job, while re-rendering a wall, or a new damp proof course and re-plastering a room, is a bigger one. We give a free, no-obligation quote once we know what is causing the problem.
We are based in Hornchurch and work across London, Essex and Kent, including Romford, Upminster, Dagenham, Barking, Ilford and Brentwood. We are open Monday to Saturday, 8am to 8pm.
Get the root problem fixed before the coldest months. Mon–Sat, 8am–8pm.
Photos are from Green Building London jobs, except the black mould and rising damp photos, which are examples from Wikimedia Commons, cropped and resized: black mould by Couch-scratching-cats (public domain); rising damp by Kebabknight (CC BY-SA 4.0).
From a leaking roof to a full garden transformation — one trusted team for every job, big or small.
Rising damp, penetrating damp, condensation and black mould. We fix the root problem, not just the surface, to stop it happening again. See how it works →
New roofs, flat roofs, re-roofing and roof repairs — carried out to a high standard using quality materials built to last.
Supply and installation of guttering, fascias and soffits to keep your property protected from the elements.
Garden landscaping, brick and block walling, re-pointing and masonry to transform outdoor spaces.
Timber and panel fencing plus garden decking, fitted securely and finished neatly.
Block-paved and slabbed patios and driveways, laid with proper drainage and long-lasting foundations.
Interior refurbishments, brickwork, plastering, tiling and electrical work — a full property maintenance service.
Green Building London Ltd is a family run company providing home improvements across Essex, London and Kent for over 15 years. We pride ourselves on providing a professional, caring and high-quality service on every job we take on.
Our work covers patios, driveways and landscaping through to building alterations, interior refurbishments, brickwork, concrete and tiling — plus roofing repairs, new roofs, flat roofs and re-pointing. We also handle septic tanks, excavation, soakaways, foundations, drainage, external works and electrical installation, rewiring and safety certificates.
A selection of roofing, landscaping and building projects completed by our team.
Real feedback from recent jobs across Essex and London.
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Tangmere Crescent, Hornchurch, RM12 5PL, United Kingdom
Mon–Sat: 8:00am – 8:00pm · Sunday: Closed