Mastic man in Portsmouth

Mastic and sealant work in Portsmouth

Portsmouth is the UK’s only island city, and most of it is packed onto Portsea Island, with houses close together and the sea never far away. We cover the island and the mainland parts of the city, including Cosham, Drayton and Farlington, resealing baths and showers, replacing window mastic and sealing joints that let in wind and rain.

Most calls are simple: sealant that’s gone black, a shower that leaks at the corner, or a window that lets in a draught. The fix always starts with removing every trace of the old sealant, because new silicone won’t stick to it. Our guide on why bathroom sealant goes mouldy explains what’s going on in that black line.

Street after street of Victorian terraces

Portsmouth is one of the most densely populated cities in the UK, and much of that comes from long rows of Victorian and Edwardian terraces in Southsea, Fratton, North End and Copnor. These are small houses with small bathrooms, often in a rear extension or carved out of a bedroom. Ventilation is poor, condensation is constant, and the sealant around baths and showers grows mould quickly.

Many of these terraces are now shared houses or flats, and baths often sit on timber floors that flex. We fill the bath before sealing, use flexible anti-fungal silicone and check the tray and enclosure corners, because those are the usual leak points. When the grout is cracked as well, it makes sense to regrout at the same time.

Front bays, in timber or uPVC, line many streets. The mastic between frame and brick or render takes the weather from the street side and needs replacing once it hardens. Parts of Portsea and Landport that were bombed in the war were rebuilt with council flats and towers, where frame and panel joints are now ageing too.

Our services in Portsmouth

• 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 Portsmouth

We’re based in Crawley and cover all of Hampshire, Portsmouth included. Mr Mastic has 20+ years’ experience, and we’re fully insured and ARBOMaster approved applicators. We use Arbo and Everbuild products, chosen to suit each joint, whether that is a bath, a bay window or a seafront sill. With 2,847+ projects completed and 98% customer satisfaction, we stand behind our work with a one-year guarantee. You’ll get a fixed price before we start.

Around Portsmouth

From the centre, the nearest railway station is Fratton station. Well-known places nearby include Tricorn Centre (0.7 miles south-west), Royal Portsmouth Hospital (0.7 miles south-west) and Charles Dickens Birthplace Museum (less than half a mile west). Around the centre, our work takes us to homes, rentals and businesses close to Manor Infant School, The Portsmouth Academy, St Edmund's Catholic School and St Wilfrid. Green spaces within reach include Milton Locks and Portsdown Hill.