Greater London · England
Window & door mastic in Northumberland Park, Greater London
Mastic around window and door frames, sills and patio doors for householders, landlords and businesses in Northumberland Park. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Cracked or shrunken mastic around the frame
- Cracked sealant at the sill ends
- Cracked internal joints between frame and plaster
DIY versus a professional finish
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Window mastic for homes and businesses in Northumberland Park
Colour matters on a frame. White, brown, anthracite grey, black and clear sealants are all available, so the line suits the frame instead of standing out. We work on uPVC windows, patio & French doors and window sills, and people most often call us about cracked or shrunken mastic around the frame and white mastic on grey or black frames.
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, in Northumberland Park as anywhere.
Whatever the size of the job, it’s backed by our 12-month guarantee.
- Location
- Northumberland Park (N17, N18)
- Wider area
- Greater London
- Cover
- A year, on every job
- Price
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Aftercare tips
So the new joints stay in good condition:
- Don’t paint over the silicone
- Walk round the house once a year and look at the joints
- Do not use solvent cleaners on the joint
- Keep timber frames painted
Try not to touch the new joint while it cures, for as long as we advise. Keep jet washers away from the frames.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. Resealing closes it.
What affects the quote in Northumberland Park
Every job gets its own quote. This is what makes a difference:
- Whether there’s mould to deal with
- The amount of work
- How many areas need sealing
- When we can work, for business premises
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote.
Asking for a quote
To make quoting easier, please include:
- How we’d reach the joints
- Any previous sealing or DIY work
- How many joints, rooms or windows are involved
- The type of property
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we’ll explain what’s involved.
For landlords and businesses
Hotels need rooms back in use, so we plan the work room by room. Hotel work is part of what we do, alongside homes and businesses.
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
What happens on the day
When we get to you, we check the joints match what you told us. If anything is different, we explain it before carrying on. After that, the work takes anything from an hour or two to a full day, depending on how many frames there are. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- First, we go round the frames with you and agree the list.
- 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.
Getting ready for the visit
- Plan for the work area to be out of bounds to pets and children
- Mention any leaks or damp you’ve noticed
- On commercial sites, let us know about site rules
How to get a quote
Want a quote for window mastic? Please phone 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear price before we start.
Advice
What we cannot put right
A few problems are outside what sealant work can do:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- Rotten timber, which needs a joiner first
- Penetrating damp from a failed cavity tray or render
If you’re not sure, just ring 0345 464 0079 or email us and we will give you a straight answer before booking.
Where we work in Northumberland Park
- Patio & French doors
- Window sills
- Timber windows & doors
- Aluminium frames
- uPVC windows
- Composite doors
When to call us in Northumberland Park
Every frame moves through the day. A plastic or aluminium frame lengthens in sunshine and shortens as it cools, while the brick or render around it hardly moves. If the sealant cannot stretch, it splits.
Signs it’s time to call us include:
- Leaking joints at the ends of sills
- Whistling draughts around closed windows
- Draughty joints inside around the window
- Black, perished sealant on frames
For site and facilities teams at buildings such as Lea Valley Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Questions to ask before you book
- What preparation is included
- What the cure time is
- The length of the guarantee
- What happens if the job turns out different
Frames and glazing around Northumberland Park
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. With historic houses such as Bruce Castle (about 0.8 miles south-west) nearby, there’s older building stock in the area around Northumberland Park as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
For an older house near a landmark such as St Paul's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. For landlords with property near Northumberland Park (London) station, renewing tired window mastic between tenants heads off draught and damp complaints.
Northumberland Park is about 1 mile north-east of Tottenham, in Greater London. If you need window mastic in Northumberland Park, please phone 0345 464 0079 or email us for a quick quote. We cover Greater London from our Crawley base. 764 places in Greater London are on our list. You can also see our page for London, about 7 miles away.
Jobs for window mastic in N17 and N18 is quoted and booked the same way as anywhere else. We cover properties on Love Lane, Park Lane and York Road. Other places close to Northumberland Park include Upper Edmonton (1 mile north-west), Edmonton (1 mile north), South Chingford (1 mile east), Picketts Lock (2 miles north-east) and Highams Park (2 miles east). Further out, we also cover London (7 miles south), City of Westminster (7 miles south-west), Marylebone (7 miles south-west), Kensington (10 miles south-west), St Pancras (6 miles south-west) and Shoreditch (6 miles south).
Local landmarks in Northumberland Park
In Northumberland Park, that means homes and buildings near Duke's Aldridge, No.8 Tottenham pub and London Academy of Excellence Tottenham. Northumberland Park has its own railway station: Northumberland Park (London) station. A little further out are North Middlesex University Hospital (0.9 miles north-west) and Markfield Beam Engine and Museum (1.6 miles south). The countryside around Northumberland Park includes Pole Hill and Highams Park Lake.
Towns and villages near Northumberland Park
What else we do in Northumberland Park
FAQs for Northumberland Park
Can you help a landlord with a rental near Northumberland Park (London) station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will send you a clear quote.
Can you do window mastic in Northumberland Park?
Yes, Northumberland Park is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or email us with a few details of the job.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Where is Mr Mastic based?
Our base is Crawley. We work across South East England, London and Scotland.
Can new sealant go over the old?
No, it won’t last. It may look fine at first, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Can you do the inside joint as well?
Yes. Inside, the joint between frame and plaster is sealed neatly, using a paintable sealant if you want to decorate.
Can resealing stop a draught around my window?
It will if the frame joint is the problem. We check where the draught is before work begins.