Greater London · England
Mastic man in Lewisham
Resealing for Lewisham’s Victorian conversions, cottage-estate houses and new town-centre flats, from Brockley and Deptford to Catford and Sydenham.
- 20+ years’ experience
- ARBOMaster approved applicator
- One-year guarantee
Your local mastic man for Lewisham
Lewisham is a borough of tall Victorian houses, many of them now split into flats, alongside big interwar council estates and a new skyline of towers around Lewisham station. Mr Mastic covers all of it from our base in Crawley: Deptford, New Cross, Brockley, Ladywell, Lee, Catford, Forest Hill, Sydenham, Downham and the streets in between.
The calls we get from the borough are usually about showers that leak into the flat downstairs, mould creeping along the edge of a bath, or window mastic that has cracked after years of weather. Each one gets the same treatment. We take out every trace of the old sealant, clean and dry the joint properly, and lay a single, tidy bead of the right product. If your shower has started to leak, our guide to leaking shower sealant explains the usual causes.
Victorian villas, converted flats and the Downham cottage estate
North Brockley was built up from the late 1840s with villas, large terraces and semi-detached houses, much of it led by the Tyrwhitt-Drake family, and it has been a conservation area since 1974. After both world wars many of these big houses were divided into flats. Conversions like that often put a bathroom on a timber floor above someone else’s kitchen, and the floor flexes every time the bath or shower tray is used. Rigid or tired sealant cracks, and water finds its way down.
Lewisham has around 30 conservation areas in total, among them Telegraph Hill, Ladywell, Lee Manor, Forest Hill, Sydenham Hill and Blackheath, so sash windows and painted timber frames are a common sight. Further south, the London County Council built the Downham estate from the late 1920s as a low-density cottage estate of more than 5,000 homes, now mostly with replacement windows whose mastic has hardened over the years.
The newest homes are around Lewisham town centre, where the Lewisham Gateway scheme is bringing around 1,000 homes in towers by the station. New flats bring their own sealant issues as buildings settle in their first couple of years.
Sealant jobs in shared houses, blocks and period terraces
A lot of Lewisham homes share a front door, a staircase or a ceiling with someone else. Before we start in a converted house or a block we check where we can park, how we get materials up the stairs and whether the managing agent needs notice. In a top-floor conversion we look closely at the shower tray and the bath end, because that is where leaks to the flat below usually start.
In the conservation areas, front sash windows and doors are part of what makes a street look right, so we keep the mastic lines around them clean and use colours that suit painted timber. Our window mastic guide explains when frame sealant needs replacing and what we use.
Student lets, healthcare and landlords around Lewisham
Goldsmiths, University of London, is in New Cross, and the streets around it have a steady turnover of shared houses and student flats. Bathrooms in those homes take heavy use, and landlords often want sealant renewed between tenancies so they start each let with clean, sound joints. Our guide on sealant for landlords covers what to check.
University Hospital Lewisham, on Lewisham High Street, is surrounded by surgeries, clinics and care homes where washrooms need hygienic, easy-to-clean sealant. We also work for shops, cafés and offices in Lewisham and Catford town centres.
What happens when you book
- Get in touch. Call or email with the job, your postcode and a few photos if you have them.
- Agree the price. You get a clear quote up front, and we book a date that suits you.
- Strip back the old joint. Every bit of old sealant is removed and the joint is cleaned, treated for mould and dried.
- Neat new sealant. Each joint gets the sealant that suits it, laid and smoothed to a tidy finish.
- Cure and guarantee. We tell you when it can be used, and every job has our one-year guarantee.
What we do in Lewisham
- Bathroom & kitchen resealing: Mouldy or split sealant around baths, shower trays, basins and sinks removed completely and replaced with a neat, hygienic bead.
- Window & door mastic: Cracked or shrunken mastic around window and door frames, sills and patio doors replaced with a weatherproof sealant.
- Commercial & hotel sealant: Guest bathrooms, staff washrooms and kitchens in commercial buildings resealed in a planned order that keeps the site running.
- Remedial sealant & repairs: Messy, layered or wrong-product sealant cut out and replaced with the right sealant, laid the right way.
- Fire-rated sealant: Intumescent and fire-rated joints around pipes, cables and frames, installed to the manufacturer’s tested specification.
- External & façade joints: Split or perished joints in walls and cladding replaced with exterior sealant designed to stretch with the building.
- New-build mastic & snagging: Failed builder sealant in new homes put right, and plot mastic for developers.
- Floor & skirting joints: Floor and skirting joints in homes, shops and warehouses sealed neatly and to the right depth.
- Regrouting: Tired or mouldy grout raked out and renewed, and the internal corners finished in flexible silicone.
- Glazing & conservatory sealant: Leaking conservatory and rooflight joints, glass panels and shower screens resealed with silicone made for glass.
- Gutter, fascia & soffit sealing: Gutter unions, outlets and fascia joints that leak in heavy rain cleaned and resealed.
- Sand mastic for sash & case windows: Traditional sand mastic for period windows and doors where a modern sealant would look out of place.
What you get with Mr Mastic in Lewisham
Lewisham homeowners tell us they want the job done properly once, not patched again next year. That’s why we bring 20+ years’ experience to every bead. Mr Mastic is fully insured and an ARBOMaster approved applicator, and we use Arbo and Everbuild sealants. Our record runs to 2,847+ projects and a 4.9-star Google rating from more than 180 five-star reviews. You will know the cost from a clear quote before we start, and the work is covered by a one-year guarantee.
Landmarks near Lewisham
For trains, Lewisham station is closest to the centre. Well-known places nearby include Lewisham Shopping Centre (less than half a mile north-west), Fan Museum (1.2 miles north) and Greenwich Castle (1.2 miles north). Closer in, we work on homes, rented flats and businesses near St Saviour's Catholic Primary School, Prendergast Vale School, St Joseph's Academy and St Stephen's Church. Nearby green spaces include Brookmill Road Local Nature Reserve and Knight's Hill.
What customers say
Rated 4.9 on Google from 180+ five-star reviews. Read the reviews on Google.
“Professional mastic man service from start to finish. They assessed the work properly, gave a clear quote, and executed the job perfectly. Very satisfied with the results.”
“1950s terrace on Crossways — bath had black mould coming back constantly. Mr Mastic stripped it all back and did it properly. Bathroom looks brand new.”
“New build in Forge Wood — shower seal had failed after 16 months. Mr Mastic came out quickly, removed everything and did it properly. Perfect finish and no more leaks.”
Neighbourhoods we cover in Lewisham
Choose your part of town for local details, or call 07833 053749 or email us and tell us your postcode.
- Blackheath
- Brockley
- Catford
- Crofton Park
- Deptford
- Hither Green
- Honor Oak
- Horn Park
- Isle of Dogs
- Ladywell
- Lee
- Maze Hill
- Millwall
- New Cross
- North Greenwich
- Nunhead
- St Johns
- Telegraph Hill
- Vanbrugh Park Estate
Also near Lewisham
Questions from Lewisham
Do you cover all of Lewisham?
Yes. We work in Deptford, New Cross, Brockley, Ladywell, Lee, Catford, Hither Green, Forest Hill, Sydenham, Bellingham and Downham, travelling up from Crawley.
Water from my shower is coming through the ceiling of the flat below. Can you help?
Often the sealant around the tray or screen has failed. We remove it, check the joint, and reseal so water stays in the enclosure; if the leak is from the plumbing, we will tell you.
I live in a converted Victorian house in Brockley. Why does my bath seal keep cracking?
Timber floors in conversions flex as the bath fills and empties. We fill the bath before sealing and use a flexible sanitary silicone so the joint can move.
Do you reseal round sash windows in conservation areas?
Yes. We cut out old mastic around the frames and use a sealant that suits painted timber, keeping the lines neat from the street.
Can you turn round a student let near Goldsmiths between tenancies?
Yes. We can reseal baths, showers and kitchens in one visit so the property is ready for the next tenants.
Do you work in the new towers by Lewisham station?
Yes. We arrange access and parking with the building management before we arrive.
Is mould under silicone something you can clean off?
Not reliably, because the mould grows into the sealant. We take the old bead out, treat the area and reseal with anti-fungal silicone.