Essex · England
Window Mastic in Harwich
We cover Harwich for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Draughts coming in around windows and doors
- Cracked internal joints between frame and plaster
- Cracked or shrunken mastic around the frame
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Walk round the house once a year and look at the joints
- Keep solvents and bleach off the sealant
- Repaint timber before it’s bare
- Clean frames with a soft cloth and soapy water
Keep sill grooves and drainage slots clear, so water can run away instead of sitting against the joint.
Signs to watch for: split or missing mastic, gaps, damp patches inside or black mould on the reveal. If you notice one, it’s time to get the joint looked at.
How we handle window mastic in Harwich
Homes in Harwich have every kind of window: from uPVC casements to timber and aluminium, along with patio doors, French doors and sills. The sealant is chosen to suit the frame material and the wall. We’re often asked to deal with cracked internal joints between frame and plaster and gaps where the sill meets the wall, on uPVC windows, patio & French doors and aluminium frames.
In a town like Harwich, older houses sit alongside newer estates, with windows of every age. In every case, the joint between frame and wall is what keeps water out.
There’s a 12-month guarantee on every job.
- Location
- Harwich (CO12)
- Wider area
- Essex
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Why it’s worth doing now in Harwich
Once mastic fails, rain can get between the frame and the wall. Over time that can mean damp patches, damaged plaster and rotting timber. Resealing now is a small job by comparison. Draughts from a gap round a frame, damp under a sill or water behind a bath panel all start small, and they’re far easier to fix early.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed. Call for a quick quote and we’ll explain what it covers.
Why Harwich clients choose us
- Full insurance on every job
- 12-month guarantee on every job
- ARBOMaster approved applicator
- Tidy, careful work
Take a look at what affects the cost and what customers say.
Landlords, agents and businesses in Harwich
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.
We also work for property managers and facilities teams. We can quote a run of properties together, and we are fully insured for the work.
Places near Harwich
Also in Harwich
Common problems we fix in Harwich
Joint shape matters as much as the product. A thin smear across a wide gap has nothing to it, and a gap filled solid cannot flex. That’s what backing rod is for.
Common reasons people contact us include:
- Rushed sealant from a window installation
- Cold air getting in at the frame edge
- Rain getting in at the frame or under the sill
- Leaking joints at the ends of sills
If you let a flat or house near Dovercourt station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Comparing quotes
- When the joint can take water or movement
- Whether VAT is included
- Which sealant they’ll use, and why
- Who does the work, and how experienced they are
What we do, step by step
Most of a good job is in the preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. In total, it generally takes a morning for a couple of windows and a door. In Harwich, parking is rarely complicated, though it helps to know about driveways or restrictions, and let us know if the work is upstairs, in a flat or up high outside.
- Each frame is looked over and we agree which ones need resealing.
- We remove the old mastic and clean the frame edge and wall.
- Where the gap is deep, backing rod goes in first.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
How to prepare
- Clear items away from the joints we are working on
- Mention any leaks or damp you’ve noticed
- For business premises, tell us about site rules or sign-in
Ask for a quote
We don’t publish a price list. Instead, we give you a clear price for your job. To arrange one, ring 0345 464 0079 or drop us an email.
Related advice
Windows and doors in Harwich
Harwich is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That is hard on the mastic around window and door frames, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Homes close to Church of All Saints include some older properties, and the joint between an old wall and a newer frame is normally the first place rain gets in. For site and facilities teams at buildings such as Harwich and Dovercourt High School, larger buildings have plenty of frames, and the mastic around each one ages.
Harwich is in Essex. We carry out window mastic for homes and businesses in Harwich. 644 places in Essex are on our list, from the larger towns to small villages. We also work in Chelmsford, around 36 miles away.
Jobs for window mastic in CO12 is quoted and booked the same way as anywhere else. Whether your property is on Station Road, High Street and Market Street or a nearby road, our applicators can take on the job. Harwich sits on or near the A120 and B1352, which makes travel easy. Close by, we work in Parkeston (1 mile north-west), Little Oakley (2 miles south-west) and Ramsey (2 miles west). Further out, we also cover Clacton-on-Sea (10 miles south-west), Greenstead (14 miles west), Wivenhoe (14 miles west), Brightlingsea (13 miles south-west), Walton-on-the-Naze (6 miles south) and Bocking's Elm (11 miles south-west).
Near you in Harwich
In Harwich, that means homes and buildings near St Joseph's Catholic Primary School and The Trafalgar Public House. The closest station to Harwich is Dovercourt station, roughly 0.9 miles north-east of the centre. Well-known places in the area include Landguard Fort (2.5 miles east) and Harwich Museum (1.3 miles north-east). Green spaces nearby include Copperas Wood.
Common questions in Harwich
Can you help a landlord with a rental near Dovercourt station?
Yes, rental work is part of what we do. Just call 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear price.
Is window mastic in a coastal place like Harwich any different?
Coastal homes put outside sealant through more weather than inland ones, so preparation and the right sealant matter all the more. Walls facing the sea are normally the first to need attention.
Does someone need to be in?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
Do the sealants smell?
Some sealants have a smell while they cure, which fades as it sets. Opening a window helps.
Do you work for hotels and businesses?
Yes. We’ve worked for hotels, offices and other businesses, and we’re fully insured.
Where is Mr Mastic based?
We are based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
How do I get a quote for window mastic in Harwich?
We do not publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Do you guarantee window mastic?
Yes. All our work carries a 12-month guarantee, and we are fully insured.
What affects the quote in Harwich
The price is agreed before any work begins. It takes into account:
- Mould in or behind the old joints
- The number of rooms or windows
- How much old sealant there is and how hard it is to remove
- Whether the work is at height
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Helping us quote
To make quoting easier, please include:
- The rough size of the job
- If it’s domestic, commercial or a hotel
- The problem you’ve noticed
- Any previous sealing or DIY work
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll explain how we’d tackle it. When it suits you, ring 0345 464 0079 or email us.
Honest limits
Honest advice matters more to us than a booking, so here’s what sealant cannot fix:
- A frame that has rotted at the joint
- Worn gaskets, brush seals or a door that has dropped
- Broken hinges, locks or handles
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think before booking.
Joints and surfaces we work on
- uPVC windows
- Patio & French doors
- Composite doors
- Aluminium frames
- Window sills
- Timber windows & doors