Greater London · England
Window Mastic in North Cray
Professional window mastic in and around North Cray, with old sealant always removed completely and a 12-month guarantee.
- Gaps between the frame and the inside reveal
- Cracked sealant at the sill ends
- Cracked or shrunken mastic around the frame
Window mastic in North Cray, done properly
If you can feel air around a shut window, the gap is often at the frame. Resealing that joint can make a room feel noticeably less draughty and quietens the whistle on windy days. If the draught is through the window seals instead, we’ll tell you. We work on aluminium frames, timber windows & doors and composite doors, and common reasons people get in touch are leaking joints at the ends of sills and rain getting in at the frame or under the sill.
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 North Cray as anywhere.
Big or small, it’s backed by our one-year guarantee in North Cray and across Greater London.
- Where
- North Cray (DA14)
- Region
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Common questions in North Cray
Is parking a problem for a job in North Cray?
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.
I let a flat near Albany Park station. Can you help?
Yes. We work for landlords and agents as well as householders, and several properties can go on one quote. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Will you leave a mess?
No. We work neatly, protect the area around the joints and tidy up afterwards.
Are you insured?
Yes. Mr Mastic is fully insured.
Can you seal the gap between the frame and the plaster indoors?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, picked for each joint. We explain the product when we quote.
Do you work on first-floor windows?
Yes, as long as they can be reached safely. Let us know about access when you ask for a quote so we can plan the job.
Places near North Cray
What else we do in North Cray
Leave it or put it right?
Draughts and leaks do not always mean new windows. If the frames and glass are in good order, resealing the joints is often all that is needed. If we find failed glass units or worn seals, we’ll tell you. 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.
Doing several joints on one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll send you a clear quote for the lot.
Why North Cray clients choose us
- 4.9 on Google from 180+ five-star reviews
- Over 20 years’ experience
- Any old sealant cut out fully, not covered over
- Colour agreed with you before any work starts
Take a look at what affects the cost and what customers say.
Can I do it myself?
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.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
When to call us in North Cray
On timber frames, paint and putty build up around the joint. Mastic painted over many times cracks with the paint, and the wood moves with damp as well as heat.
The problems people generally mention when they call are:
- Draughty joints inside around the window
- White mastic on grey or black frames
- Water coming in at the bottom corners of a door
- Cracked sealant at the sill ends
In the older streets around Parish Church of St James, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Before you book anyone
- How the colour is chosen
- What insurance they hold
- How the joint is cleaned and prepared
- What happens if they find a problem under the old sealant
Honest limits
We’d rather tell you now than do work that won’t last, so these are the limits:
- Draughts through the window seals rather than the frame
- Rotten timber, which needs a joiner first
- Misting between the panes of a double-glazed unit (that needs a new unit)
If you are not sure, just ring 0345 464 0079 or email us and we will give you a straight answer before booking.
Where we work in North Cray
- uPVC windows
- Timber windows & doors
- Composite doors
- Aluminium frames
- Window sills
- Patio & French doors
North Cray homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking. With historic houses such as Hall Place and Gardens (about 1.4 miles north-east) nearby, there’s older building stock in the area around North Cray as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
If you look after a building such as Royal Park Primary Academy, larger buildings have plenty of frames, and the mastic around each one ages. For landlords with property near Albany Park station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
North Cray is about 2 miles east of Sidcup, in Greater London. Our applicators cover window mastic for homes and businesses in North Cray and nearby. 764 places in Greater London are on our list, from the larger towns to small villages. We also work in London, about 11 miles from North Cray.
Every address in DA14 is covered for window mastic. You’ll find streets such as Water Lane, North Cray Road and Leafield Lane. If you are just outside North Cray, we cover Bexley (1 mile north), Coldblow (1 mile north-east), Ruxley (1 mile south), Blendon (1 mile north-west) and Joyden's Wood (1 mile east). We also work in nearby towns such as London (11 miles north-west), City of Westminster (14 miles north-west), Marylebone (14 miles north-west), Kensington (15 miles west), St Pancras (13 miles north-west) and Shoreditch (11 miles north-west).
Near you in North Cray
Typical jobs here are in homes near Foots Cray Meadows, Cleeve Park School and The White Cross pub. The nearest railway station is Albany Park station, about 0.6 miles north-west of the centre. A little further out are Broadway Shopping Centre (1.7 miles north) and Bexley Hospital (1.8 miles north). For a walk, there’s Wansunt Pit and Summer Hill.
How the visit works
You do not need to clear the whole room or building before we come, just the space around the work. Everything nearby is protected, and the work takes anything from an hour or two to a full day, depending on how many frames there are for a typical job. In North Cray, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- 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
- Try not to wet indoor joints just before the visit
- Keep children and pets away from the work area
- For business premises, tell us about site rules or sign-in
How to get a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or email us.
Read more
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Keep drainage slots and sill grooves clear
- Keep paint and stain on wooden frames in good order
- Keep paint off silicone joints
- Look round the frames every year or so
Timber frames need their paint kept up, because bare, wet timber moves more and pulls at the joint. Paint up to the joint, not over the silicone.
Water gets in quietly when mastic fails. Often the first sign is a damp patch inside or flaking paint on the reveal. Catching it early keeps the fix to a reseal.
What the job involves on each surface
Composite doors
Composite doors are normally hung in an uPVC-type frame, so its perimeter joint is sealed much like a window. The bead is colour-matched to the frame.
Window sills
Every drop off the glass ends up on the sill, so the joints at each end and underneath matter. They’re cut out and resealed with exterior sealant.