Greater London · England
Window & door mastic in Winchmore Hill, Greater London
Window and door frames in Winchmore Hill need attention? We remove the old material, prepare the joints and seal them properly.
- Damp patches on the reveal after heavy rain
- Gaps left after new windows were fitted
- Gaps where the sill meets the wall
Winchmore Hill questions
Do you work for landlords with property near Winchmore Hill station?
Yes, we work for letting agents and landlords. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
Can parking be tricky for a visit in Winchmore Hill?
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.
Will resealing my frames help with draughts?
It will if the frame joint is the problem. We find where the air is coming from before we reseal.
How many windows can you do in a day?
A few frames take a few hours, while a whole house takes longer. We confirm the timing with your quote.
Can you get sealant to suit coloured frames?
Yes. Grey and black frames get grey or black sealant, and wood-effect frames generally suit brown.
Is it OK to seal over old sealant?
No, it won’t last. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Where is Mr Mastic based?
We’re a Crawley-based firm. We work across South East England, London and Scotland.
What does window mastic cost?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or send us an email with a short description of the job.
Window mastic for homes and businesses in Winchmore Hill
Over two decades of sealing frames has taught us which products suit which walls. We are fully insured ARBOMaster approved applicators, and every job is covered by a 12-month guarantee. We work on aluminium frames, window sills and patio & French doors, and common reasons people get in touch are cracked internal joints between frame and plaster and a bead that doesn’t match the frame.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, letting in draughts and water.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or drop us an email.
- Place
- Winchmore Hill (N21, N13, N9)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Surface by surface
Aluminium frames
Coated aluminium needs a compatible sealant, and acetoxy silicones aren’t used, as they can attack some metals. Neutral-cure sealant is the safe choice.
uPVC windows
Plastic frames move a lot between a hot afternoon and a cold night, so we use a flexible, low-modulus sealant. We match white, brown, anthracite grey and black frames.
How to look after the new joints
To keep the joints looking good and working properly:
- Do not paint over the silicone
- Look round the frames every year or so
- Keep jet washers away from the mastic
- Keep solvents and bleach off the sealant
Keep sill grooves and drainage slots clear, so rain drains out rather than building up at the sealant.
Look out for the warning signs: split or missing mastic, gaps, damp patches inside or black mould on the reveal. If you notice one, it’s time to get the joint looked at.
Also near Winchmore Hill
Also in Winchmore Hill
What affects the quote in Winchmore Hill
The price is agreed before any work begins. It’s based on:
- How easy the joints are to reach
- The number and length of the joints
- The old material and how stubborn it is
- The type of sealant required
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first and give you a clear price before any work starts.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Whether it’s a home or a business
- The rough size of the job
- Where the job is, and your postcode
- Any previous sealing or DIY work
Asking for a quote is easy: let us know what needs doing and where, and roughly how big it is. Photos by email help us understand the job.
Can I do it myself?
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.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly.
How it works
You don’t need to clear the whole room or building, just the space around the work. Everything nearby is protected, and the work takes a few hours for a few frames, or a day or more for a whole house in most cases. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Winchmore Hill. 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, along with any loose debris.
- Frame and wall are cleaned and must be dry before sealing.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
Getting ready for the visit
- Move anything stored near the joints
- Tell us about any previous sealing or DIY attempts
- Mention any parking rules near the property
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. Whenever you’re ready, call 0345 464 0079 or email us.
Related advice
When it isn’t the sealant
We’d rather tell you now than do work that won’t last, so here’s what sealant cannot put right:
- Draughts through the window seals rather than the frame
- Misting between the panes of a double-glazed unit (that needs a new unit)
- Penetrating damp from a failed cavity tray or render
If you’re not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer.
What we seal
- Composite doors
- Window sills
- uPVC windows
- Aluminium frames
- Patio & French doors
- Timber windows & doors
Window mastic in Winchmore Hill: local notes
Historic houses like Bruce Castle (about 2.6 miles south-east) are a reminder that the area around Winchmore Hill has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you look after a building such as St. Paul's School, larger buildings have plenty of frames, and the mastic around each one ages. For landlords with property near Winchmore Hill station, renewing tired window mastic between tenants heads off draught and damp complaints.
Winchmore Hill is about 2 miles north-west of Edmonton, in Greater London. Whether you are in the middle of Winchmore Hill or further out, we cover window mastic for every kind of property. We cover 764 towns and villages across Greater London. London is on our list too, about 9 miles from Winchmore Hill.
Jobs for window mastic in N21, N13 and N9 is quoted and booked the same way as anywhere else. If you need window mastic at a property on Farm Road, Arlow Road and Hurst Road or anywhere close by, we can help. Other places close to Winchmore Hill include Bush Hill (1 mile north-east), Bush Hill Park (1 mile north-east), Enfield (1 mile north-east), Enfield Chase (2 miles north) and Edmonton (2 miles south-east). We also work in nearby towns such as London (9 miles south), City of Westminster (9 miles south), Marylebone (8 miles south), Kensington (10 miles south-west), St Pancras (7 miles south) and Shoreditch (8 miles south).
Local landmarks in Winchmore Hill
Around Winchmore Hill, our work takes us to homes and buildings near Winchmore School, Keble Preparatory School and The Kings Head pub and the streets around them. There’s a railway station in Winchmore Hill itself: Winchmore Hill station. A little further out are Museum of Enfield (1.4 miles north-east) and Edmonton Green Shopping Centre (1.9 miles east). Green spaces nearby include Darland's Lake and Barfield Allotments Nature Park.
When to call us in Winchmore Hill
Timber windows bring their own problems. Old mastic gets painted over and cracks under the paint, and timber moves with moisture as well as temperature.
Look out for these signs:
- Black, perished sealant on frames
- Gaps between the frame and the inside reveal
- Gaps left after new windows were fitted
- Leaking joints at the ends of sills
As a London address, Winchmore Hill can be tricky for parking: let us know about parking bays, permits or a driveway.
Comparing quotes
- How the joint is cleaned and prepared
- What the cure time is
- What happens if they find a problem under the old sealant
- Whether they’re fully insured