Essex · England
Mastic man in Harwich
Resealing and weatherproof window mastic for Harwich Old Town’s Georgian-fronted houses, Dovercourt’s Victorian terraces and homes facing the sea and estuary.
- Old sealant cut out, never covered
- ARBOMaster approved
- One-year guarantee on every job
Resealing and mastic work across Harwich
Harwich is surrounded by water on three sides, and its buildings take the weather from almost every direction. Window and door mastic here works harder than it would inland, drying, cracking and letting in rain on the exposed faces of houses in the Old Town and along the Dovercourt seafront. Mr Mastic covers Harwich and Dovercourt from our base in Crawley.
We cut out failed external mastic and replace it with flexible, weatherproof sealant, and inside we reseal baths, showers, basins and kitchens. Old sealant always comes out completely before anything new goes on. Our guide to window mastic explains why it fails and what a good joint should look like.
A medieval street plan and a Victorian resort
The Old Town keeps its medieval street plan, with main streets linked by narrow alleys and buildings on small plots. Many are medieval or later timber-framed houses, but most were refronted in the Georgian period with red brick, sash windows and decorative doorways. Some are rendered in pastel colours, weatherboarding is painted black or white, and roofs are pantile or slate. The conservation area holds 150 listed buildings and structures, including a sailmaker’s house thought to date from around 1600.
Lower Dovercourt was developed from the mid-19th century as a seaside resort, planned by John Bagshaw, though only Orwell Terrace was built to his masterplan. Kingsway has red-brick Victorian terraces with two-storey bays and was built up by the 1920s, Victoria Street has colourful Victorian terraces and Orwell Road has grand rendered ones. Sash windows are typical, though some have been replaced with uPVC.
Bays are hard on mastic. Each one has several frames, a sill and a roof joint, and on a seaside street they face the worst of the weather. We check every joint, not just the obvious cracks.

Sea air, exposed fronts and tight Old Town streets
Salt air, wind-driven rain and strong sun all shorten the life of exterior sealant, especially on frames facing the sea or the estuary. Once a joint opens, rain gets behind the frame and into the wall. We use weatherproof sealants set at the right depth with backing rod, and on painted timber sashes we often choose a paintable product rather than silicone.
Old Town streets are narrow and many houses open straight onto the pavement, so let us know about parking and access when you book. In converted houses and flats, we pay close attention to bath and shower joints, because a leak there reaches the rooms below. Where the bathroom is on an outside wall, we also check the window reveal, as condensation runs down the glass and sits on the sealant there.
The port, hotels and holiday lets
Harwich International Port at Parkeston, about a mile upstream from the Old Town quays, runs regular ferries to the Hook of Holland, and the visitors it brings stay in hotels, guest houses and holiday lets around the town. The Pier Hotel on the quayside dates from 1860. Busy guest bathrooms need resealing more often, and our guide to hotel bathroom resealing explains how we keep disruption low.
Dovercourt has the main shopping centre, with shops and flats above them, and we also work for landlords and letting agents resealing between tenancies.
What happens when you book
- Tell us about the job. A quick call or email with what needs sealing and where. Photos help us quote accurately.
- Quote and booking. We quote clearly before anything starts and fix a day that works for you.
- Preparation first. Old sealant out completely, surfaces cleaned, mould treated and the joint left dry.
- Seal and finish. The right sealant for each joint is applied and tooled to a neat, even finish.
- Leave it to cure. We tell you how long to leave it before use, and the work carries our one-year guarantee.
Jobs we take on in Harwich
- Bathroom & kitchen resealing: Bathroom and kitchen joints taken back to a clean, dry surface and finished with fresh anti-fungal silicone that won’t lift.
- Window & door mastic: Cracked or shrunken mastic around window and door frames, sills and patio doors replaced with a weatherproof sealant.
- Commercial & hotel sealant: Sealant programmes for offices, hotels, care settings and schools, with early or late working where it helps.
- Remedial sealant & repairs: Leaks and lifting beads from earlier sealant jobs put right, starting with finding out why they failed.
- Fire-rated sealant: Gaps in fire-separating walls and floors sealed with fire-rated products, following the tested details for each one.
- External & façade joints: Outside movement joints given new backing rod and a flexible, weatherproof sealant in a colour to match the wall.
- New-build mastic & snagging: Early-failing sealant in new homes fixed properly, plus mastic packages and snagging for developers.
- Floor & skirting joints: Gaps under skirting boards, tile movement joints and concrete floor joints sealed with a product that suits the traffic.
- Regrouting: Crumbling grout in showers and wet areas raked out and refilled, so water stays out of the wall behind.
- Glazing & conservatory sealant: Conservatory, rooflight, glass panel and shower screen joints resealed with glazing silicone.
- Gutter, fascia & soffit sealing: Dripping gutter joints and end caps, and gaps at fascias and soffits, sealed with weatherproof exterior sealant.
- Sand mastic for sash & case windows: Old sand mastic around sash windows and doors raked out and renewed with traditional burnt sand mastic.
Why Mr Mastic in Harwich
Seaside sealant has to be done properly or it won’t last a winter. Mr Mastic has more than 20 years’ experience and has completed over 2,847 projects. We’re fully insured, ARBOMaster approved and use Arbo and Everbuild sealants suited to exposed joints. Our customers have left 180+ five-star reviews for a 4.9-star Google rating. You’ll have a clear quote before we start and a one-year guarantee once we’re done.
Landmarks near Harwich
The nearest station to the town centre is Dovercourt station. Places most people will know nearby are Harwich Museum (1.3 miles north-east) and Landguard Fort (2.5 miles east). Typical jobs near the centre are in homes and businesses around St Joseph's Catholic Primary School, Harwich and Dovercourt High School, Church of All Saints and The Trafalgar Public House. Nearby green spaces include Copperas Wood.
What customers say
Rated 4.9 on Google from 180+ five-star reviews. Read the reviews on Google.
“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.”
“Harper Drive in Maidenbower — kitchen worktop had been leaking behind for a while. Came out the next day, sorted it properly. Really tidy job.”
“Called for a bathroom reseal and the mastic man showed up on time with all the right equipment. Brilliant attention to detail. The sealant looks perfect and they kept everything tidy.”
Parts of Harwich we work in
Choose your part of town for local details, or call 07833 053749 or email us and tell us your postcode.
Other towns around Harwich
Your questions about mastic work in Harwich
Do you cover all of Harwich?
Yes. We cover the Old Town, Dovercourt and Lower Dovercourt, Parkeston, and nearby Little Oakley and Ramsey.
Why does mastic on my seafront windows crack so quickly?
Salt air, wind and sun dry out and stress exterior sealant. We replace hardened mastic with a flexible, weatherproof product set at the right depth.
Can you reseal the bay windows on my Dovercourt terrace?
Yes. We check each frame, the sill and the joint where the bay meets the wall, and reseal any that have failed.
My Old Town house is listed. Can you still help?
Yes. Inside resealing is usually routine. For external work on a listed building, check with Tendring District Council first and we can explain exactly what we would do.
Do you reseal guest bathrooms in hotels and holiday lets?
Yes. We can work room by room or between bookings so you can keep letting the rest.
Should I use silicone or a paintable sealant on my timber sashes?
Silicone can’t be painted, so where the frame and joint will be painted we usually suggest a paintable exterior sealant. We’ll explain the difference before we start.
Is parking a problem in the Old Town?
The streets are narrow, so let us know about parking and access when you book.
Is the work guaranteed?
Yes, with our one-year guarantee on every job.
