07576 573615tom@cbsdamp.co.uk Mon–Fri 8am–8pm · Sat 8am–1pm · Sun closed About Services Areas Our work Contact 07576 573615Request Free Survey HomeAreas coveredLondon Damp proofing in London # Damp proofing in Londonfor period housingthat stays dry London's solid-wall terraces, converted flats and cellared townhouses generate most of the damp we treat. Free survey, honest diagnosis, fixed price, and ten-year guarantees on the treatment. Request your free survey 07576 573615 Free survey and diagnosis anywhere in London · 10-year workmanship and QANW insurance-backed guarantees 10 years Company workmanship guarantee on damp treatment 10 years QANW insurance-backed guarantee £0 Survey, diagnosis and fixed-price quotation in London £2m Public liability insurance held Local coverage ## A London damp specialist working on London's building stock The business is London-based and works across the capital, with our registered address in Harrow and most of our work concentrated in West and North West London and the neighbouring Middlesex towns. That matters practically: we are dealing with the same housing types week after week, so a Victorian nine-inch wall in a terrace with a failed slate damp proof course is familiar ground rather than an unusual case. London's stock is unusually damp-prone. Vast numbers of solid-brick Victorian and Edwardian terraces were built with slate or bitumen damp proof courses that have now reached the end of their life; countless houses have been converted into flats, adding new floor levels, new wet rooms and new penetrations through old walls; and the city is full of basements and cellars that were never designed as habitable rooms but are now used as them. Add ground levels that have crept up over a century of new paving, patios and pavement resurfacing, and you have the two conditions that produce most of our work: failed or bridged damp proof courses, and water entering through eroded pointing and failed render on exposed elevations. We survey anywhere in London free of charge, including evenings up to 8pm on weekdays and Saturday mornings, which suits people who cannot take time off to meet a contractor. ### Areas we cover within London - West London - North West London - Harrow - Brent - Ealing - Wembley - Kensington & Chelsea - Camden - Hammersmith - Richmond - Barnet - Hounslow ### Property types we work on Victorian and Edwardian terraces, mansion blocks and converted flats, interwar semis, townhouses with cellars, and commercial ground floors. ### Common London requests Rising damp after a homebuyer survey, penetrating damp on exposed elevations, and cellars being brought back into use. ### Access and logistics Terraced streets, restricted parking, shared access and leasehold flats are normal here, and we plan work and access around them. ### When you can reach us - Monday8am – 8pm - Tuesday8am – 8pm - Wednesday8am – 8pm - Thursday8am – 8pm - Friday8am – 8pm - Saturday8am – 1pm - SundayClosed Services in London ## Every service available across London ### Rising damp treatment A failed damp proof course is diagnosed, treated with an accredited Sovereign or Wykamol system and replastered to a decoration-ready finish, priced as a fixed sum before any work starts, and guaranteed for ten years. Rising damp treatment in London ### Penetrating damp treatment Damp that worsens after rain is coming in from somewhere. We find the route: pointing, render, sills, gutters or roof detail; correct it, then repair the wall inside. Free survey, fixed price, no guesswork. Penetrating damp treatment in London ### Damp surveys & diagnosis Find out exactly what is causing the damp, what it takes to fix it, and what it costs, in writing, at a fixed price, with no charge for the visit and no obligation to proceed. Damp surveys & diagnosis in London ### Structural waterproofing & tanking Below-ground rooms need a waterproofing system, not a coat of damp-seal paint. Membrane and cementitious tanking specified to suit the structure, installed as an approved Sovereign and Wykamol contractor, with a free survey and a fixed price. Structural waterproofing & tanking in London ### Plastering The replaster is half of any damp repair. We remove contaminated plaster, apply the specified salt-retardant system and leave a flat, decoration-ready finish, as part of a fixed price, by the same contractor that treated the wall. Plastering in London ### Rendering Cracked, hollow or blown render holds water against your masonry. We identify why it failed, repair or renew it with a system suited to the substrate, and fix the damp it was causing inside. Rendering in London ### Brickworks & repointing Open joints and spalled brick faces are the most common route for penetrating damp. We cut out properly, repoint in a mortar matched to your brick, and replace masonry that has broken down. Brickworks & repointing in London ### Brick stitching Helical stainless bars bonded into the bed joints tie cracked brickwork back into one structure, a repair carried out from the outside, without rebuilding the wall, and finished so the crack disappears. Brick stitching in London ### General building Damp repairs rarely stop at the damp. We carry out the associated building work: masonry, render, plaster, joinery repairs and making good, so the job finishes with one contractor accountable for all of it. General building in London ### Small refurbishment & remedial works Treatment stops the damp; remedial work makes the room liveable again. Plaster, joinery, floors, decoration preparation and making good, completed by the contractor that did the specialist work, at a fixed price. Small refurbishment & remedial works in London Why choose us ## Why London homeowners use Charge Building Services ### Diagnosis before specification Every job starts with a free survey. London damp is frequently misdiagnosed; condensation in a converted flat sold as rising damp, and the survey is where that gets settled. ### Two ten-year guarantees Damp treatment carries a 10-year company workmanship guarantee and a separate 10-year QANW insurance-backed guarantee, which matters when London properties change hands so often. ### Approved contractor Approved contractor for Sovereign and Wykamol, so accredited products and systems are used and installed to the manufacturer's specification. ### Fixed prices, no day rates A written fixed price for a defined scope before work starts, paid 50% deposit and 50% on completion by bank transfer. ### Damp and building work together Repointing, render, brick stitching, plastering and making good handled by the same business, which avoids chasing trades across London. ### Insured to £2,000,000 Public liability insurance held to £2,000,000, with paperwork available for managing agents and freeholders who ask for it. Local damp problems ## Why London properties suffer damp more than most London's damp problems come from the age and construction of its housing, the way that housing has been altered, and the ground it sits on. Solid brick walls with no cavity have no air gap to interrupt moisture, so once a damp proof course fails or the pointing erodes, the inside face gets wet. The London Clay that underlies much of the capital holds water and shrinks and swells with the seasons, which contributes to the thermal and movement cracking that lets water into masonry. Exposure is the other factor: the prevailing south-westerly weather drives rain hard onto exposed flank walls, and those are the elevations where render and pointing fail first. ### Failed Victorian damp proof courses Slate and bitumen DPCs in 19th-century terraces have reached the end of their service life, producing classic tide marks and blown plaster at skirting level. ### Raised external ground levels A century of new paving, patios and pavement build-up has left thousands of London houses with ground above DPC level, bridging an otherwise sound barrier. ### Exposed flank and gable walls End-of-terrace and corner properties take driven rain on a large unprotected elevation, where eroded pointing and blown render admit water. ### Cellars used as rooms London basements built as coal stores are now utilities, gyms and bedrooms, and they need proper structural waterproofing rather than paint. ### Flat conversions and condensation Subdivided houses with new kitchens and bathrooms, sealed windows and limited ventilation produce condensation that is routinely mistaken for rising damp. ### Parapets, valleys and chimneys London terraces are full of parapet walls, hidden valley gutters and redundant chimney stacks, all frequent sources of high-level penetrating damp. Our process ## The same five steps on every job in London 01 ### Free survey and diagnosis We inspect the property, identify the actual cause of the damp and explain it in plain terms. No charge, no obligation. 02 ### Fixed-price written quotation A clear fixed price for the specified works, built around your property, never a day rate. 03 ### Works carried out Accredited Sovereign and Wykamol systems installed, walls replastered and the area made good. 50% deposit, 50% on completion by bank transfer. 04 ### Verification and making good Treatment checked for continuity, plaster left flat and decoration-ready, and the area cleaned down. 05 ### Guarantees issued A 10-year company workmanship guarantee plus a 10-year QANW insurance-backed guarantee on damp treatment. In detail ## Damp proofing across London in detail ### Rising damp in London terraces The single most common job across London is a failed damp proof course in a solid-walled terrace or semi. The evidence is consistent: a tide mark at a fairly even height, salt deposits on the wall face, plaster that sounds hollow and crumbles when tapped, paint peeling at skirting level and skirtings that are soft at the back. Treatment means injecting a new chemical damp proof course into the mortar bed using an accredited Sovereign or Wykamol system, then removing the salt-contaminated plaster and replacing it with a salt-retardant render and skim. Both halves are essential, an injection without the replaster leaves hygroscopic salts in the wall that keep the surface damp. Before any of that is specified we check what else could be responsible, because in London the answer is often bridging rather than DPC failure. Raised patios, new paths, render carried down past the DPC and rubble in a cavity are all common, and correcting them can cost far less than a full treatment. ### Penetrating damp on exposed London elevations Damp that appears or worsens after heavy rain is water crossing the external envelope. In London that usually means eroded mortar joints on a flank wall, cracked or debonded render holding water against the brickwork, perished sealant around windows, missing drip details on sills, or a blocked or split rainwater pipe soaking one narrow band of wall. High-level and roof details deserve their own mention because London's housing is full of them: parapet walls with defective copings, hidden valley gutters between terraces, and chimney stacks with failed flashings or open flues. Each produces a distinctive internal pattern: a ceiling stain, damp at the top of a wall, or a chimney breast that is wet on one side. We correct the defect and then repair inside. Repointing in a mortar mix matched to soft London stock brick, patching or renewing render, replacing spalled bricks, resealing openings, and stitching cracked masonry where movement has opened a route for water. ### Basements, cellars and structural waterproofing London's cellars were built for coal and storage, not for living in. Turning one into a usable room means managing water arriving under pressure from the surrounding ground, which is a job for a cementitious tanking system or a cavity drain membrane with perimeter drainage and, where gravity discharge is not possible, a sump and pump. Which system is right depends on the structure and how wet it is. Cementitious tanking bonds to sound masonry and resists water as a barrier; a membrane system accepts that water will arrive and manages it to a drain. Both are installed as accredited systems with the junctions, penetrations and returns detailed properly, because that is where basement waterproofing fails. What does not work is waterproof paint. It cannot resist hydrostatic pressure, and every London cellar we see with peeling coatings on the wall is evidence of that. ### Damp, surveys and London property transactions London property changes hands constantly, and damp is one of the most frequently flagged defects in valuations and homebuyer reports. Buyers ask for retentions, lenders ask for specialist reports, and sales stall while everyone waits for a figure. Our free survey produces the two things needed to move on: a clear statement of what is actually causing the damp, and a written fixed-price quotation for putting it right. Where treatment goes ahead, the 10-year workmanship guarantee and the 10-year QANW insurance-backed guarantee provide the documentation buyers, surveyors and lenders look for. If you are selling, having that in hand before marketing keeps control of the conversation. If you are buying, it tells you what the real number is rather than the worst case a survey implies. ### Where we work across London and beyond Most of our London work is in the west and north west of the capital: Harrow, Brent, Wembley, Ealing and the surrounding boroughs, and we work more widely across London on request. Outside the capital we cover Middlesex, Watford, Slough, Buckinghamshire, High Wycombe and Surrey. Calls are taken Monday to Friday 8am to 8pm and Saturday 8am to 1pm, and surveys where a sale, remortgage or tenancy is waiting on the answer are prioritised. Tell us your deadline when you call and we will be straight about whether we can meet it. Questions ## Damp proofing in London, common questions Do you cover all of London?We work across London, with most of our work concentrated in West and North West London including Harrow, Brent, Wembley and Ealing. Tell us the postcode when you call and we will confirm straight away. How quickly can you get to a property in London?We take calls Monday to Friday 8am to 8pm and Saturday 8am to 1pm and book surveys around your availability, including evenings. Jobs where a sale, remortgage or tenancy is waiting on the report are prioritised, tell us your deadline. How much does damp proofing cost in London?There are no published prices, because no two walls are the same: wall length and thickness, replastering height, access and any bridging corrections all change the scope. The survey, diagnosis and written fixed-price quotation are free. Do you handle urgent damp and water ingress in London?Active water ingress is prioritised for survey within our working hours of Monday to Friday 8am to 8pm and Saturday 8am to 1pm. Call and describe what is happening. Do you work on leasehold flats and blocks?Yes. Be aware that responsibility for an external defect often sits with the freeholder or managing agent, and we will tell you at survey where we think that applies so you are not paying for someone else's repair. Can you treat damp in a London basement or cellar?Yes: structural waterproofing using accredited cementitious tanking or cavity drain membrane systems, with drainage and pumping where the levels require it. Is your work guaranteed?Damp treatment carries a 10-year company workmanship guarantee plus a separate 10-year QANW insurance-backed guarantee. Building works carry a 6-month workmanship guarantee. My London surveyor's report mentions damp; what now?Book a free survey and bring the report. We will confirm the actual cause, tell you which items are genuinely urgent, and issue a written fixed-price quotation you can use in the transaction. Are you insured to work on my property?Yes, public liability insurance is held to £2,000,000, and we can provide details for managing agents or freeholders who ask. Do you charge for the survey or quotation in London?No. The survey, the diagnosis and the written fixed-price quotation are free, anywhere we cover, with no obligation to proceed. Free survey ## Book a free damp survey anywhere in London Send us the postcode and a description of what you are seeing; height of the staining, whether it follows the rain, and how long it has been there. We will arrange a survey and give you a written fixed price. - Free survey, diagnosis and written fixed-price quotation in London - 10-year company workmanship guarantee on damp treatment - 10-year QANW insurance-backed guarantee - Sovereign & Wykamol approved contractor - £2,000,000 public liability insurance Call 07576 573615 Nearby areas ## We also cover ### Damp proofing in Chelsea Chelsea's Georgian and Victorian stucco terraces, garden squares, lower-ground floors and vaults under the pavement each bring a particular set of damp risks. Free diagnosis, a written fixed price, and ten-year guarantees on damp treatment. View area ### Damp proofing in Ealing Solid-brick Victorian and Edwardian villas, cellars, converted flats and parapet-fronted terraces: Ealing's housing stock rewards a careful survey. Free diagnosis, a written fixed price, and ten-year guarantees on damp treatment. View area ### Damp proofing in Harrow We are registered and based in Harrow, so this is where we know the streets, the housing stock and the recurring faults best. Free survey, honest diagnosis, fixed price and ten-year guarantees on damp treatment. View area ### Damp proofing in West London West London's Victorian terraces, Edwardian conversions and interwar semis are the properties we work on most. Free survey and diagnosis, a written fixed price, and ten-year guarantees on damp treatment. View area ### Damp proofing in Brent Brent's terraces, converted flats and interwar semis produce a steady stream of misdiagnosed damp. We survey free, identify the real cause and quote a fixed price with ten-year guarantees on treatment. View area ### Damp proofing in Middlesex We are based in Ealing, so Middlesex is home ground. Interwar semis, period terraces and modern extensions, free survey, honest diagnosis, fixed price and ten-year guarantees on damp treatment. View area All areas coveredAll servicesHomeContact Damp proofing, structural waterproofing and remedial building works across London and the surrounding counties. Tom Charge, Owner. ### Contact - 07576 573615 - tom@cbsdamp.co.uk - C/O MG Tax, 166 College Road, Harrow, England HA1 1BH ### Hours - Monday8am – 8pm - Tuesday8am – 8pm - Wednesday8am – 8pm - Thursday8am – 8pm - Friday8am – 8pm - Saturday8am – 1pm - SundayClosed ### Guarantees - 10-year company workmanship guarantee - 10-year QANW insurance-backed guarantee - 6-month guarantee on building work - Sovereign & Wykamol approved contractor - £2,000,000 public liability insuranceAboutServicesAreasOur workContact ### Damp proofing & building services - Rising damp treatment - Penetrating damp treatment - Damp surveys & diagnosis - Structural waterproofing & tanking - Plastering - Rendering - Brickworks & repointing - Brick stitching - General building - Small refurbishment & remedial works ### Areas we cover - Harrow - Pinner - Stanmore - Edgware - Ealing - Chiswick - Isleworth - Chelsea - Middlesex - Brent - London - West London - Watford - Slough - Buckinghamshire - High Wycombe - Surrey © 2026 Charge Building Services Ltd. 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