Greater London · England
Hampstead Window Mastic
Specialist window mastic for Hampstead: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Untidy mastic left by window fitters
- Old mastic that has gone black or come away
- Cracked internal joints between frame and plaster
About our window mastic in Hampstead
The new joint doesn’t have to be white. We can seal in white, brown, anthracite grey, black or clear, so the line suits the frame instead of standing out. If you are dealing with cold air getting in at the frame edge and mastic that has split away from the wall, we can help, whatever the surface.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in Hampstead as anywhere.
Big or small, it’s backed by our 12-month guarantee in Hampstead and across Greater London.
- Place
- Hampstead (NW3, NW6, NW11, N2)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Landlord and commercial work in Hampstead
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
We work for letting agents and landlords as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
Common problems we fix in Hampstead
Water runs down the glass onto the sill, so the sill ends and the joint below the frame are common leak points. Failed sealant there lets rain into the wall or behind the frame.
People generally contact us after spotting one of these:
- Leaking joints at the ends of sills
- Rain getting in at the frame or under the sill
- Black, perished sealant on frames
- Rushed sealant from a window installation
In the older streets around St John-at-Hampstead church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Comparing quotes
- Whether the sealant suits the joint
- Whether they’re fully insured
- Who turns up on the day
- Is the old sealant removed completely?
What the job involves on each surface
Timber windows & doors
Timber moves with moisture as well as heat, so the joint must stay flexible. The paint or stain needs to be sound where the sealant meets it.
Window sills
Masonry sills can have joints where water gets in, including the one between the sill and the frame above. Those are sealed with a product suited to stone or concrete.
Window mastic in Hampstead: local notes
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. With historic houses such as Fenton House (about 0.4 miles north) nearby, there’s older building stock in the area around Hampstead as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
Managing a site like Fitzjohn's Primary School? Then the mastic around its windows and doors needs looking after like any other building’s. Hampstead is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Hampstead is about 3 miles north-west of City of Westminster, in Greater London. Across the NW3 area, our applicators can take on window mastic. Across Greater London, we cover 764 places, and Hampstead is one of them.
Jobs for window mastic in NW3, NW6, NW11 and N2 is quoted and booked the same way as anywhere else. We cover properties on Hampstead High Street, New End Square and The Mount Square. With the A1 and A502 close by, Hampstead is easy for our applicators to reach for window mastic. We also cover the places around Hampstead: Greenhill (1 mile north-east), West Hampstead (1 mile west), Fortune Green (1 mile west), Vale of Health (1 mile north) and South Hampstead (1 mile south). Larger places within reach include London (5 miles south-east), City of Westminster (3 miles south-east), Marylebone (3 miles south-east), Kensington (4 miles south), St Pancras (3 miles south-east) and Shoreditch (5 miles south-east). Hampstead is one of the larger places we cover in Greater London.
Local landmarks in Hampstead
Typical jobs here are in homes near South Hampstead High School, Kilburn Grange Park and St Anthony's Preparatory School. Also close by are King William IV Public House (within half a mile north-east) and Cecil Sharp House (1.7 miles south-east). Hampstead has its own railway station: Finchley Road & Frognal station. A little further out are Isokon Gallery (0.8 miles east) and New End Hospital (under half a mile north). For a walk, there’s Belsize Wood and The Long Water.
The process
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The work itself takes most of a day for a typical house, less for a few frames from start to finish. In Hampstead, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- Each frame is looked over and we agree which ones need resealing.
- The old mastic is cut out and scraped back to clean surfaces.
- Deep gaps get closed-cell backing rod to set the depth.
- The new sealant goes on in white, brown, anthracite grey, black or clear to suit.
- We tool each bead neatly and check every joint is closed.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Try not to wet indoor joints just before the visit
- Mention any parking rules near the property
Getting a quote
For window mastic in Hampstead, call 0345 464 0079 or email us. Tell us what the problem is and where, and we will agree the price before any work begins.
Advice
What affects the quote in Hampstead
Every job gets its own quote. This is what makes a difference:
- Whether the work is at height
- Working hours on commercial sites
- Which sealant suits the joint
- The size of the job
Doing several joints on one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. We will give you a clear price for the lot.
What to tell us for a quote
To make quoting easier, let us know:
- Roughly how big the job is
- What’s wrong with the joints now
- Whether it’s a home or a business
- Photos by email, if that is easy
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Nearby places to Hampstead
What else we do in Hampstead
Why act early in Hampstead
Choosing the product is half the job. Decorators’ caulk and bathroom silicone are not designed for outside joints that move. A low-modulus exterior sealant keeps its stretch through hot and cold weather. Damp from a failed joint spreads quietly in older London brickwork and timber, and by the time it shows on a wall or ceiling in Hampstead, the repair is bigger than the sealant job would have been.
Leaving a failed joint usually makes the job bigger, not smaller, as water and mould keep getting in. If you are unsure, ring 0345 464 0079 or send us an email for an honest opinion and a quote.
What you get with us
- Old sealant always removed completely
- Colour agreed with you before we start
- ARBOMaster approved applicator
- Quality sealants from Arbo and Everbuild
Take a look at how sealant jobs are priced or our reviews.
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Hampstead: your questions answered
Can you do window mastic in Hampstead?
Yes, Hampstead is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear quote.
Can parking be tricky for a visit in Hampstead?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
What information do you need?
A short description and the location, with pictures by email if possible. We will ask anything else we need to know.
Can landlords and businesses book you?
Yes. We work for homeowners, landlords, letting agents, businesses and hotels in Hampstead.
Will it make a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
Can I paint over the new sealant?
Silicone generally will not take paint. If you plan to paint, tell us first and we can use a paintable sealant where it suits the joint.
Do I have to be there?
It depends on the job. For work indoors, someone needs to let us in.
Can you reach windows above the ground floor?
Yes, where it’s safe. Higher or awkward frames may need extra access, and we’ll confirm what’s needed.