Black mould and streaming windows traced to the real cause, then fixed with ventilation and moisture control that lasts. Covering Hackney, Kensington & Chelsea and Islington & Camden and across London.
Book a surveyCondensation is the most common cause of black mould in London homes, and it often gets mistaken for rising or penetrating damp. Bleach and mould-resistant paint only treat the symptom.
Our surveyors take humidity, temperature and surface readings to understand why moisture is building up in your property, then recommend changes that stop the mould returning.
Condensation is one of the most common problems in London flats, especially in converted houses where kitchens and bathrooms have been added without enough ventilation, and in mansion blocks with solid, uninsulated walls.
We provide independent assessments for landlords, managing agents and tenants across the capital.
London's housing stock is dominated by Victorian and Edwardian terraces, Georgian townhouses and mansion blocks, many now split into flats. Most were built with solid brick walls and original slate or bitumen damp proof courses that are now well over a century old. Raised pavements and garden levels, lower ground floors and shared party walls all make damp more likely, and conversions often introduce new kitchens and bathrooms without enough ventilation.
Dense streets, flats with limited airflow and the city's warm, sheltered microclimate mean condensation and hidden leaks are common. Moisture from a flat above or a neighbouring property can travel a long way before it shows, often reaching floor voids and timbers first.
Victorian terraces converted into flats alongside large estates, where condensation and black mould in bedrooms and bathrooms are among the most frequent call-outs.
Stucco-fronted townhouses and mansion blocks with lower ground floors and vaults under the pavement, where basement waterproofing and damp to front lightwells are everyday problems.
Georgian and early Victorian terraces, often listed and split into flats, where lime-compatible damp treatments and leaks between flats need careful diagnosis.
Every home produces moisture from cooking, showering, drying clothes and simply breathing. When warm, moist air meets a cold surface such as a window, an external corner or an uninsulated wall, it condenses. Where ventilation can't remove that moisture fast enough, black mould follows.
Solutions depend on the property. They may include positive input ventilation (PIV) units that gently replace moist air with filtered fresh air, continuous-running extractor fans in kitchens and bathrooms, humidity-controlled fans, improved trickle ventilation, or insulating cold spots. We also check for hidden leaks and penetrating damp that can make condensation worse.
For landlords and managing agents, our written report gives a clear, independent assessment of the cause, which is invaluable where responsibility is disputed.
A PCA-qualified, commission-free surveyor visits your London property, investigates with calibrated equipment and identifies the cause.
You receive a clear written report explaining what we found and what we recommend, with a fixed quotation and no hidden extras.
Our own trained team carries out the work, protecting your home, keeping dust down and leaving everything clean.
You receive a written guarantee, which can be protected by an Insurance Backed Guarantee for a single premium.
Our surveyors are in London every day, travelling in from our Thames Ditton office in south-west London. We regularly work in Bromley, Acton, Balham, Battersea, Biggin Hill and Blackheath, and throughout Westminster, Kensington & Chelsea, Hammersmith & Fulham, Wandsworth, Lambeth and Southwark.
Towns and areas we cover in London
Find out more about our condensation & mould control service.
Book a survey
If you’ve noticed any of these issues, arranging a professional survey is the best way to identify the cause and prevent further damage.
In winter, windows are closed, heating cycles on and off and walls are colder, so moisture has fewer ways out and more cold surfaces to condense on. Improving ventilation is usually the long-term fix.
It can help in a single room but rarely fixes the cause on its own. A whole-house approach to ventilation and cold spots is more effective and cheaper to run long term.
It depends on the cause. Lifestyle plays a part, but the building's ventilation, insulation and condition are often the main factors. Our independent report helps landlords and tenants in London understand what is causing the problem.
Persistent mould and damp can affect indoor air quality and may aggravate allergies, asthma and other respiratory conditions in some people, so it is worth tackling promptly.
Yes. Much of our London work is in flats, maisonettes and lower ground floor conversions. We can liaise with managing agents and freeholders where the cause of a problem sits in a communal part of the building or a neighbouring flat.
Yes. Our teams work in central London every week and plan for parking suspensions, congestion charge zones and restricted access, so you don't have to.
Our surveyors are in London every day, travelling in from our Thames Ditton office in south-west London. Towns we visit regularly include Bromley, Acton, Balham, Battersea, Biggin Hill, Blackheath, East Ham and Hammersmith. If yours isn't listed, give us a call and we'll confirm.
Also in London
Our other specialist services for London homes, landlords and businesses.
Rising damp, penetrating damp and damp proof courses. Most common around Kensington & Chelsea and Richmond & Barnes.
Dry rot, wet rot and woodworm. Most common around Greenwich & Lewisham and Kensington & Chelsea.
Basement damp proofing, tanking and conversions. Most common around Kensington & Chelsea and Richmond & Barnes.
Pre-purchase and mortgage surveys. Especially worthwhile for older homes around Kensington & Chelsea and Islington & Camden.
Wall tie replacement and crack stitching. Most common around Wandsworth & Clapham and Croydon & Bromley.
Leaks, floods and burst pipes. Most common around Richmond & Barnes and Kensington & Chelsea.
Client testimonials
I would like to thank Tapco for the work they carried out recently on my flat in Kingston. Both me and my partner are very happy with the service we received and the quality of their work. I wouldn't hesitate using them again.
Live just outside London? We cover the neighbouring counties too.
Find the right service / 1 minute
Tell us what you’re seeing and we’ll point you to the right treatment. Four quick questions.
From our offices in Thames Ditton and Esher, our surveyors cover London and the surrounding counties, providing fast response times for residential and commercial properties alike.
We regularly work with:
Whether your property requires a damp survey, timber inspection or basement waterproofing system, our experienced team is ready to help.
Our certifications reflect our commitment to the highest standards of work and quality.
Why Tapco
Established in 1971
Choosing Tapco HomeDry means choosing a company with a proven history of protecting properties across the South East.
We believe every property deserves an individual assessment. That’s why our recommendations are based on what your building genuinely needs, not unnecessary treatments.
Tapco (Preservation) Ltd is an Introducer Appointed Representative (Financial Services Register No. 423558) of Phoenix Financial Consultants Limited (Phoenix). Phoenix is a credit broker, not a lender. Phoenix is authorised and regulated by the Financial Conduct Authority (FRN: 539195), and offers finance from its panel of lenders. All finance subject to status and credit checks.
