Greater London · England
Chelsea Harbour Window Mastic
Specialist window mastic for Chelsea Harbour: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Sealant in the wrong colour for the frame
- Water coming in at the bottom corners of a door
- Whistling draughts around closed windows
Window mastic in Chelsea Harbour, done properly
The new joint does not have to be white. We can seal in white, brown, anthracite grey, black or clear, so the bead blends with the window rather than framing it. We work on uPVC windows, window sills and patio & French doors, and the jobs we see most are black, perished sealant on frames and cracked internal joints between frame and plaster.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in Chelsea Harbour.
We guarantee the work for a year. If something is not right with it in that time, tell us and we will put it right.
- Location
- Chelsea Harbour (SW6, SW11, SW10)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Why deal with it now?
A cracked joint around a frame lets rain into the wall. Left long enough, it can stain inside walls, spoil plaster and rot wooden frames. Resealing now is a small job by comparison. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler for homes in Chelsea Harbour.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
Why Chelsea Harbour customers choose us
- Tidy, careful work
- A choice of colours where the product allows
- Fully insured
- Experience in homes, commercial sites and hotels
Take a look at what affects the cost and customer reviews.
What the job involves on each surface
Timber windows & doors
Soft or rotten wood cannot be sealed successfully. If we find rot, we will tell you before going ahead, as that’s a job for a joiner.
Patio & French doors
Door frames take knocks and movement every time the doors are used. The sealant must cope with it without cracking.
Chelsea Harbour homes and the weather
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you live in an older home near St Mary's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Managing a site like Chelsea Academy? Then larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Imperial Wharf station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Chelsea Harbour is about 2 miles south-east of Kensington, in Greater London. For window mastic in and around Chelsea Harbour, please phone 0345 464 0079 or drop us an email for a quick quote. We’re based in Crawley and cover Greater London, Chelsea Harbour included. Across Greater London, we cover 764 places, and Chelsea Harbour is one of them.
Work in SW6, SW11 and SW10 works the same way as everywhere else we cover. You will find streets such as Ann Lane, York Road and Lots Road, and we cover them all. Neighbouring places we cover for window mastic include Sands End (1 mile south), Walham Green (1 mile north-west), World's End (1 mile north), Little Chelsea (1 mile north) and Parsons Green (1 mile west). We also work in nearby towns such as London (4 miles north-east), City of Westminster (3 miles north-east), Marylebone (3 miles north-east), St Pancras (4 miles north-east), Shoreditch (6 miles north-east) and Walthamstow (10 miles north-east).
What’s near Chelsea Harbour
Around Chelsea Harbour, our work takes us to homes and buildings near Heatherley School of Fine Art, Lots Road pub and Imperial Park. Nearby too are Langford Primary School (within half a mile south-west) and Natural History Museum Library and Archives (1.5 miles north). Chelsea Harbour has its own railway station: Imperial Wharf station. Other landmarks nearby include Baynard's Castle (4.3 miles north-east) and Chelsea Stadium Tour And Museum (0.6 miles north-west). Not far away are WWT London Wetland Centre and Battersea Park Lake.
Also near Chelsea Harbour
More services for Chelsea Harbour
When something else is needed
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Broken hinges, locks or handles
- Misting between the panes of a double-glazed unit (that needs a new unit)
- Worn gaskets, brush seals or a door that has dropped
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think.
Joints and surfaces we work on
- Window sills
- Aluminium frames
- uPVC windows
- Composite doors
- Timber windows & doors
- Patio & French doors
What happens on the day
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. All told, the work takes a morning for a couple of windows and a door. In Chelsea Harbour, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Deep gaps are filled with backing rod to set the depth.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Every joint is checked before we leave.
How to prepare
- Let us know if you’ve seen damp or leaks
- Let us know about stairs, lifts or work at height
- Move anything stored near the joints
Ask for a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, phone 0345 464 0079 or drop us an email.
Related advice
FAQs for Chelsea Harbour
Is parking an issue for window mastic in Chelsea Harbour?
Parking in Chelsea Harbour, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
I let a flat near Imperial Wharf station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Do you have sealant for grey or black windows?
Yes, we choose a colour to suit the frame. Anthracite grey, black, brown and white cover most frames, with clear as an option.
Do you do commercial work?
Yes, regularly. We can plan bigger jobs in stages.
Is the new sealant paintable?
Most silicone cannot be painted. If you plan to paint, tell us first and we can use a paintable sealant where it suits the joint.
Is the work guaranteed?
Yes. Our 12-month guarantee covers every job, inside or out.
Do you come to Chelsea Harbour?
Yes. We are based in Crawley and work across South East England, London and Scotland, Chelsea Harbour included.
How much does window mastic cost in Chelsea Harbour?
We don’t publish prices, because the cost depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Quotes for window mastic in Chelsea Harbour
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The number and length of the joints
- Whether there’s mould to deal with
- Which sealant suits the joint
- Any working-time requirements on site
What it costs depends on the amount of work, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start.
Asking for a quote
To help us quote quickly, please include:
- How we’d reach the joints
- Whether it has been sealed before
- If it’s domestic, commercial or a hotel
- Roughly how big the job is
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job.
Landlord and commercial work in Chelsea Harbour
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can be quoted together.
We work for landlords and letting agents as well as homeowners. Sealant work between tenants keeps a property looking cared for before the next move-in.