Greater London · England
Window & door mastic in New Cross, Greater London
Mastic around window and door frames, sills and patio doors in New Cross, with a one-year guarantee on every job. Ask us for a quote.
- Untidy mastic left by window fitters
- A bead that doesn’t match the frame
- Black, perished sealant on frames
Do you need window mastic in New Cross?
Sun, frost and rain wear sealant out. UV light hardens the outside of the bead, until it loses its stretch and starts to crack.
People normally contact us after spotting something like this:
- Rain getting in at the frame or under the sill
- White mastic on grey or black frames
- Cracked internal joints between frame and plaster
- Mastic that has split away from the wall
If you live in an older home near St James's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Before you book anyone
- How the surfaces are prepared before sealing
- What product goes in the joint
- Who does the work, and how experienced they are
- What happens if the job turns out different
About our window mastic in New Cross
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We’re ARBOMaster approved and fully insured, and we give a one-year guarantee on the work. We work on uPVC windows, composite doors and patio & French doors, and common reasons people get in touch are gaps where the sill meets the wall and draughty joints inside around the window.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in New Cross.
Our work is backed for twelve months, in New Cross and everywhere else we cover.
- Place
- New Cross (SE8, SE14, SE4)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the quote in New Cross
The price is agreed before any work begins. It takes into account:
- Mould in or behind the old joints
- How many areas need sealing
- Whether the work is at height
- The size of the job
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
Helping us quote
To make quoting easier, let us know:
- Photos by email, if that’s easy
- The type of property
- Any access issues, like height or stairs
- The rough size of the job
Quotes start with a quick conversation. Describe the problem, the location and the size of the job. When it suits you, ring 0345 464 0079 or email us.
More services for New Cross
Frames and glazing around New Cross
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
As a London address, New Cross can be tricky for parking: let us know about parking bays, permits or a driveway. Rented homes near New Cross station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
New Cross is about 3 miles south-east of London, in Greater London. Jobs in New Cross get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. 764 places in Greater London are on our list, from the larger towns to small villages.
We work across the SE8, SE14 and SE4 postcode area for window mastic and the streets around it. Window mastic is available to properties on Ivy Road, Mona Road and Avon Road and the roads around them. With the A2209 and A2210 close by, New Cross is easy for our applicators to reach. Other places close to New Cross include St Johns (1 mile east), Telegraph Hill (1 mile south-west), Deptford (1 mile north-east), Nunhead (1 mile south-west) and Lewisham (1 mile south-east). Within a short drive, we also cover London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north-west).
Local landmarks in New Cross
In New Cross, that means homes and buildings near Wickham Arms, Fordham Park and Addey and Stanhope School and the streets around them. Nearby too are St. Paul's (0.7 miles north-east) and Laban Centre (0.9 miles north-east). There’s a railway station in New Cross itself: New Cross station. A little further out are Fan Museum (1.2 miles north-east) and Greenwich Castle (1.5 miles east). Not far away are St. James's Park Lake and Tower Hill.
New Cross: your questions answered
Is parking an issue for window mastic in New Cross?
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.
Can you do window mastic in New Cross?
Yes. Our work covers London and the South East, and New Cross is part of that. You can phone 0345 464 0079 or email us and let us know what needs doing.
Do you work for hotels and businesses?
Yes. We can plan bigger jobs in stages.
Is the work guaranteed?
Yes. All our work carries a 12-month guarantee, and we are ARBOMaster approved applicators.
Is there any odour?
There can be a smell while the sealant cures, but it fades. Ventilation helps.
Do you take out the old sealant first?
Yes, every time. New silicone does not stick to old silicone, so any old material comes out before anything new goes in.
I rent my home. Can I book you?
Yes, but check with your landlord or agent first. Landlords are often happy for the work to be arranged.
Should I try DIY first?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.
When something else is needed
We’ll always be straight with you, so here’s what sealant cannot fix:
- A frame that has rotted at the joint
- Broken hinges, locks or handles
- Misting between the panes of a double-glazed unit (that needs a new unit)
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly before booking.
Surfaces we seal
- Composite doors
- Aluminium frames
- uPVC windows
- Timber windows & doors
- Window sills
- Patio & French doors
For landlords and businesses
For anyone letting property in or around New Cross, several properties can go on one quote. Just tell us the addresses and what each one needs.
We work for landlords and letting agents as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
The process
The work is kept neat and contained to the area we are working on. The job generally takes a morning for a couple of windows and a door, and we tell you how long to leave it before we go. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in New Cross. It helps if you can point us to a visitor permit or a bay close to the door.
- First, we confirm safe access to each frame.
- Old, cracked mastic is removed completely.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Backing rod fills deep voids and the sealant goes in on top.
- We tool the joint so water runs off, then clear up.
Preparing for the visit
- Mention any parking rules near the property
- Tell us about any previous sealing or DIY attempts
- On commercial sites, let us know about site rules
Get a quote
Need a quote? Please call 0345 464 0079 or send us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
Surface by surface
uPVC windows
The frame is cleaned with a product that will not harm the plastic, then the new bead is laid against the frame and the wall and tooled smooth.
Window sills
Sills catch the water running down the glass, so the sill ends and the joint under the frame are vital. They’re cut out and resealed with exterior sealant.
Why act early in New Cross
Getting a straight, even bead on an outside frame takes practice, especially upstairs. A professional job is cut out properly, backed where needed and finished neatly, using a product chosen for the frame and wall. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in New Cross, the repair is bigger than a sealant job.
The cost depends on the size of the job, how much old material has to come out and how easy the joints are to reach. You will have a clear quote before any work starts, so you know where you stand.
Why us?
- We never seal over old sealant
- One-year guarantee on every job
- Domestic, commercial and hotel work
- Arbo and Everbuild products