Mastic man in London

Mastic and sealant work in London

If you’re looking for a mastic man in London, you probably have a bead of sealant that has gone black, split or come away from the bath. We reseal baths, showers, basins and kitchen worktops, replace tired mastic around windows and doors, and seal external joints on homes and commercial buildings in every part of Greater London.

Every job starts the same way: the old sealant comes out completely. New silicone won’t bond to old silicone, so sealing over the top only hides the problem for a few weeks. Once the joint is clean and dry, we lay a single neat bead of the right product. Our bathroom resealing page explains each step.

Terraces, conversions and mansion blocks

Much of London’s housing is Victorian and Edwardian: long terraces of brick houses, many now split into two or three flats. In a conversion, the bathroom often sits directly above someone else’s ceiling. A failed bath seal that would only stain a joist in a house can mean a damp patch, a stained ceiling and an awkward conversation with the neighbour below. So when we reseal in a converted flat, we look hard at where the bath meets the wall, the tray corners and the edge of any shower screen, because those are the usual leak paths.

Mansion blocks and purpose-built flats bring their own jobs. Bathrooms are often small and poorly ventilated, so condensation sits on the sealant and mould follows. Some older blocks still have timber sash windows, while others had uPVC or aluminium replacements years ago, and the mastic around those frames is now hard and cracked. We cut it out, use backing rod where the gap is deep and apply a flexible sealant to suit the frame and the wall.

Newer flats are not immune. Builders’ sealant in new-build bathrooms often fails in the first year or two as the building settles and the shower is used every day. We also seal brickwork movement joints and the joints between render, cladding and frames. If your building dates from before 2000 and the old mastic looks original, read our guide on whether old mastic could contain asbestos before anyone disturbs it.

Our services in London

• Bathroom & kitchen resealing: Baths, showers, basins, wet rooms, worktops and sinks: old sealant cut out, mould treated and a new bead of anti-fungal silicone laid.
• Window & door mastic: Cracked or shrunken mastic around window and door frames, sills and patio doors replaced with a weatherproof sealant.
• Commercial & hotel sealant: Hotels, offices, washrooms and welfare areas resealed room by room, with out-of-hours working possible to arrange.
• Remedial sealant & repairs: Failed, botched or over-sealed joints stripped out, the cause found and the joint resealed properly.
• Fire-rated sealant: Fire-rated and intumescent sealant around gaps, frames and service penetrations, to the product’s tested details.
• External & façade joints: Brickwork movement joints, render and cladding joints resealed with backing rod and flexible exterior sealant.
• New-build mastic & snagging: Failed builder sealant in new homes put right, and plot mastic for developers.
• Floor & skirting joints: Skirting-to-floor gaps, tiled floor movement joints and concrete floor joints sealed with the right product.
• Regrouting: Cracked, stained or crumbling grout raked out and replaced, with corners resealed in silicone.
• Glazing & conservatory sealant: Conservatory, rooflight, glass panel and shower screen joints resealed with glazing silicone.
• Gutter, fascia & soffit sealing: Leaking gutter joints, end caps, fascia and soffit joints resealed with exterior sealant.
• Sand mastic for sash & case windows: Traditional burnt sand mastic renewed around sash and case windows and doors in stone and brick.

Why Mr Mastic in London

Mr Mastic is based in Crawley and has worked across London and the South East for more than 20 years. We’re fully insured, we’re ARBOMaster approved applicators and we use Arbo and Everbuild sealants. We’ve completed 2,847+ projects and hold a 4.9-star Google rating from over 180 five-star reviews. You’ll get a fixed price before we start, and every job carries our one-year guarantee.

Around London

From the centre, the nearest railway station is Elephant & Castle station. Well-known places nearby include Gabriel's Wharf (0.8 miles north-west), Surrey Dispensary (less than half a mile south-east) and Museum of Life Sciences (less than half a mile north-east). Around the centre, our work takes us to homes, rentals and businesses close to Charles Dickens Primary School, Ark Globe Academy, London School of Musical Theatre and St George the Martyr. Green spaces within reach include Bellenden Road Nature Garden and Tower Hill.