Greater London · England
Leaves Green Window Mastic
Mastic around window and door frames, sills and patio doors in Leaves Green, with a 12-month guarantee on every job. Call for a quick quote.
- Draughts coming in around windows and doors
- Hard, cracked sealant around windows
- Water coming in at the bottom corners of a door
Window mastic in Leaves Green, done properly
A cold draught around a closed window often comes from the frame edge. A new joint stops the air getting through and quietens the whistle on windy days. If the draught is through the window seals instead, we will tell you. Common call-outs are for mastic that’s falling out in pieces and leaking joints at the ends of sills, across aluminium frames, composite doors and window sills.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
The work is covered for a year after we finish. If there’s a problem with it, please ring 0345 464 0079 or drop us an email.
- Location
- Leaves Green (BR2)
- Region
- Greater London
- Guarantee
- One year on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Aftercare tips
To keep the joints looking good and working properly:
- Keep jet washers away from the mastic
- Paint up to the joint, not over it
- Wipe condensation off the frames
- Use gentle cleaners on frames and sealant
Silicone cannot generally be painted, so mention any painting plans before any work starts. There are paintable sealants for joints that need it.
Look out for the warning signs: cracks in the mastic, gaps you can see light through, damp on the reveal or mould around the inside of the frame. If you notice one, it’s time to get the joint looked at.
The process
We bring everything the job needs with us. Once we’ve agreed what’s being done, the area is protected and the work begins. It normally takes a few hours for a handful of frames, longer for a whole house. In Leaves Green, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- Each frame is looked over and we agree which ones need resealing.
- We remove the old mastic and clean the frame edge and wall.
- 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.
Getting ready for the visit
- Move anything stored near the joints
- For indoor joints, keep the area dry beforehand if you can
- Tell us if parking is tricky
How to get a quote
To get a quote, call 0345 464 0079 or email us and tell us where the job is and what the problem looks like. You’ll have a clear quote before work begins.
Related advice
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Why it’s worth doing now in Leaves Green
Choosing the product is half the job. Interior caulk and bathroom silicone aren’t made for exterior frame joints. An exterior, low-modulus sealant stays flexible in sun and frost. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
What you get with us
- Rated 4.9 stars on Google
- A choice of colours where the product allows
- Arbo and Everbuild products
- Neat joints and a tidy finish
What the job involves on each surface
Window sills
Where a sill meets brick or render, the ends often crack first. We reseal them so rain cannot run into the wall.
Composite doors
Draughts round the door leaf generally come from worn seals or adjustment, not the mastic. We seal the frame and let you know about anything else.
When it isn’t the sealant
Sealant is not the answer to every problem, and we’d rather say so up front. It won’t solve:
- Worn gaskets, brush seals or a door that has dropped
- A frame that has rotted at the joint
- Damp problems in the wall away from the window
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
Where we work in Leaves Green
- Composite doors
- Window sills
- uPVC windows
- Patio & French doors
- Aluminium frames
- Timber windows & doors
Questions from Leaves Green
Is Leaves Green in your area for window mastic?
Yes, Leaves Green is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we will give you a clear quote.
Can parking be tricky for a visit in Leaves Green?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Can you quote for more than one area?
Yes, we can. More than one area can go on one quote.
Do you remove the old sealant?
Always. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Do you seal inside as well as outside?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We can do either or both.
Can tenants book the work?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Are you insured?
Yes. Mr Mastic is fully insured, and we’ve been doing sealant work for more than 20 years.
Can you do upstairs windows?
Yes, if safe access is possible. Higher or awkward frames may need extra access, and we will confirm what’s needed.
Signs you need window mastic in Leaves Green
A lot of older mastic was never designed to stay flexible. Once it’s rigid, every bit of frame movement pulls at it, and a gap opens along one edge.
Most people get in touch after spotting one of these:
- Cold air getting in at the frame edge
- Cracked internal joints between frame and plaster
- Cracked sealant at the sill ends
- Rain getting in at the frame or under the sill
Rented homes near Hayes (Kent) station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Before booking anyone
- How long the guarantee is
- Which colour the sealant will be
- What happens if they find a problem under the old sealant
- Who turns up on the day
Window mastic in Leaves Green: local notes
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. Historic houses like Down House (about 1.1 miles east) are a reminder that the area around Leaves Green has older buildings as well as new. 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 Keston Parish Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. As a London address, Leaves Green can be tricky for parking: let us know about parking bays, permits or a driveway.
Leaves Green is about 4 miles south of Bromley, in Greater London. Homes, rented property, offices and hotels in Leaves Green is covered for window mastic. Every job comes with our 12-month guarantee. Our Greater London coverage runs to 764 places, and Leaves Green is one of them. You can also see our page for London, roughly 12 miles from Leaves Green.
Postcode districts we cover here for window mastic: BR2. Window mastic is available to properties on Ashmore Lane and Main Road and the roads around them. We also cover the places around Leaves Green: Farthing Street (1 mile north-east), Downe (1 mile east), Nash (1 mile north-west), Luxted (1 mile south-east) and Keston (2 miles north). We also work in nearby towns such as London (12 miles north-west), City of Westminster (15 miles north-west), Marylebone (15 miles north-west), Kensington (15 miles north-west), St Pancras (14 miles north-west) and Shoreditch (14 miles north).
What’s near Leaves Green
Typical jobs here are in homes near The Kings Arms and South Park and the streets around them. The closest station to Leaves Green is Hayes (Kent) station, about 2.8 miles north. Other landmarks nearby include Bethlem Museum of the Mind (3 miles north) and Princess Royal University Hospital (2.2 miles north-east). Green spaces nearby include Nore Hill and West Kent Golf Course nature reserve.
What affects the quote in Leaves Green
You’ll get a clear quote before work begins. It’s based on:
- The old material and how stubborn it is
- The size of the job
- Any mould that needs treating
- How easy the joints are to reach
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are unsure, call 0345 464 0079 or email us and we will give you an honest view and a quote.
Asking for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- Where the job is, and your postcode
- Roughly how big the job is
Getting a quote is simple: let us know what needs doing and where, and roughly how big it is. A few photos by email make the job easier to understand, and we will come back to you with a quote.