Greater London · England
Window Mastic in Euston
Our applicators work in Euston on mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Water coming in at the bottom corners of a door
- White mastic on grey or black frames
- Mastic that is falling out in pieces
What happens if it’s left?
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
What you pay reflects the work, not a rough estimate. That is why we ask about the job first and agree the price before starting.
Why choose Mr Mastic in Euston
- Anti-fungal sanitary silicone in wet areas
- More than 20 years in sealant work
- Sealant colour chosen to suit
- We agree the colour with you first
See our cost guide and our reviews.
How we handle window mastic in Euston
From a single sill to a whole house of windows, you will get a clear quote before any work starts. Just ring 0345 464 0079 or email us and tell us how many frames there are and how they’re reached. We work on composite doors, window sills and aluminium frames, and common reasons people get in touch are cold air getting in at the frame edge and rain getting in at the frame or under the sill.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
The work is covered for a year after we finish. If anything is not right with it, phone 0345 464 0079 or drop us an email.
- Where
- Euston (NW1W, W1T, NW1)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear price before we start
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Also near Euston
Also in Euston
DIY versus a professional finish
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Keep timber frames painted
- Do not use solvent cleaners on the joint
- Paint up to the joint, not over it
- Air rooms to keep condensation down around windows
Try not to touch the new joint while it cures, following the cure time we give you. Keep jet washers away from the frames.
A small gap around a frame only grows. As the old mastic shrinks further, more air gets through, and a cold room gets colder. A new joint closes it up.
Different surfaces, different methods
Composite doors
An exposed front door gets wind-driven rain, and the top and bottom corners tend to fail first. We pay most attention there.
Timber windows & doors
Wood swells when it’s wet and shrinks when it dries, so a flexible sealant is essential. We seal onto sound, dry paintwork or timber.
What we’re called out for in Euston
Every frame moves through the day. Sun on a frame makes it expand, and it contracts again overnight, while the masonry beside it stays put. A sealant that can’t keep up eventually tears.
Common reasons people contact us are:
- Draughty joints inside around the window
- A bead that doesn’t match the frame
- Black, perished sealant on frames
- Cracked or shrunken mastic around the frame
As a London address, Euston can be tricky for parking: let us know about parking bays, permits or a driveway.
Before booking anyone
- What product goes in the joint
- Which colour the sealant will be
- Whether VAT is included
- The length of the guarantee
What happens on the day
Good joint work is mostly preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. In total, it normally takes a morning for a couple of windows and a door. In Euston, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- First, we go round the frames with you and agree the list.
- The old mastic is cut out and scraped back to clean surfaces.
- Where the gap is deep, backing rod goes in first.
- 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.
How to prepare
- For indoor joints, keep the area dry beforehand if you can
- Tell us about any water getting in
- Keep children and pets away from the work area
Get a quote
Call for a quick quote, or email us if that is easier. Tell us about the joints that need doing and we’ll explain what’s involved.
Advice
Euston: your questions answered
Is parking a problem for a job in Euston?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Do you work for landlords with property near London Euston station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before work begins.
How long before the joint can be used?
That depends on the sealant used, so follow the cure time we give you when we finish.
Will resealing my frames help with draughts?
Often, yes. Air often gets in between the frame and the wall, and sealing the inside and outside joints closes that path.
Can new sealant go over the old?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. It all has to come out first.
Do you guarantee window mastic?
Yes. Every job comes with our 12-month guarantee, and we are ARBOMaster approved applicators.
Do you remove the old sealant?
Yes, every time. New silicone doesn’t stick to old silicone, so any old material comes out before anything new goes in.
Are you an approved applicator?
Yes. We are an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
What affects the quote in Euston
There’s no set price list, because jobs vary so much. What we look at:
- Mould in or behind the old joints
- The number and length of the joints
- Working hours on commercial sites
- How much old sealant there is and how hard it is to remove
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
What we need to know
To help us quote quickly, please include:
- Any access issues, like height or stairs
- Whether it has been sealed before
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is.
Windows and doors in Euston
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Handel Hendrix House (about 1.1 miles south-west) are a reminder that the area around Euston has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
In the older streets around St Pancras New Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Rented homes near London Euston station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Euston is about 1 mile west of St Pancras, in Greater London. Whether you’re in the middle of Euston or further out, we cover window mastic for every kind of property. Euston is one of 764 places in Greater London where we work.
Jobs for window mastic in NW1W, W1T and NW1 is quoted and booked the same way as anywhere else. Whether your property is on Euston Road, Duke's Road and Phoenix Road or a nearby road, we can help. Main roads around Euston include the A501 and A4200, so getting to you is simple. Nearby, we also carry out window mastic in Somers Town (1 mile north), Fitzrovia (1 mile south-west), Bloomsbury (1 mile south-east), Kings Cross (1 mile north-east) and St Pancras (1 mile east). Further out, we also cover London (3 miles south-east), Kensington (4 miles south-west), Walthamstow (6 miles north-east), Whitechapel (3 miles east), Hampstead (3 miles north-west) and Ruislip (12 miles west).
Near you in Euston
We work in homes and buildings around Lewis Cubitt Park, The Doric Arch pub and Maria Fidelis Catholic School FCJ, among other places. You will also find St Aloysius Catholic Primary School (within half a mile north) and Wellcome Collection (under half a mile south-west). There’s a railway station in Euston itself: London Euston station. Other landmarks nearby include Brunswick Centre (less than half a mile south-east) and Wellcome Collection (within half a mile south-west). Green spaces nearby include Primrose Hill and St. James's Park Lake.