Greater London · England
Brockley Hill Window Mastic
Window mastic for Brockley Hill and the surrounding area: careful preparation, the right product and tidy work. Call for a quick quote.
- Cracked internal joints between frame and plaster
- Water coming in at the bottom corners of a door
- Cold air getting in at the frame edge
Brockley Hill: your questions answered
Is parking a problem for a job in Brockley 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.
I let a flat near Elstree & Borehamwood station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before we start.
Can new window sealant be painted?
Silicone generally will not take paint. If you plan to paint, tell us first and we can use a paintable sealant where it suits the joint.
Is there any odour?
There can be a smell while the sealant cures, but it fades. Opening a window helps.
Can new sealant go over the old?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Will new mastic stop draughts?
Yes, where the draught is at the frame edge. We find where the air is coming from before we reseal.
What sealant do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Can you quote for more than one area?
Yes, we can. Several rooms, windows or areas can go on one quote.
About our window mastic in Brockley Hill
Colour matters on a frame. White, brown, anthracite grey, black and clear sealants are all available, so the bead blends with the window rather than framing it. If you have gaps left after new windows were fitted and mastic that’s falling out in pieces, we can help, whatever the surface.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Location
- Brockley Hill (HA7, HA8, WD6)
- Region
- Greater London
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
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.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Why act early in Brockley Hill
Choosing the product is half the job. Decorators’ caulk and bathroom silicone aren’t designed for outside joints that move. An exterior, low-modulus sealant stays flexible in sun and frost. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler for homes in Brockley Hill.
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs. Ask us for a quote and we will explain what it covers.
Why choose Mr Mastic in Brockley Hill
- Quality sealants from Arbo and Everbuild
- Homes, businesses and hotels
- 12-month guarantee on every job
- Fully insured
Take a look at how sealant jobs are priced and what customers say.
What affects the cost of window mastic
For a quick quote, just ask. The main things that affect it are:
- The number and length of the joints
- Which sealant suits the joint
- When we can work, for business premises
- How many rooms, windows or areas are involved
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Asking for a quote
You don’t need to know the technical terms. It helps if you can tell us:
- Whether it has been sealed before
- The address or postcode of the job
- A few photos by email, if you can
- The type of property
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll talk you through the work.
When something else is needed
We will not take on work that will not last, so here’s what sealant cannot put right:
- Damp coming through the wall itself rather than the frame joint
- Broken hinges, locks or handles
- Misting between the panes of a double-glazed unit (that needs a new unit)
If you’re not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
Surfaces we seal
- Patio & French doors
- Composite doors
- uPVC windows
- Aluminium frames
- Timber windows & doors
- Window sills
Nearby places to Brockley Hill
What else we do in Brockley Hill
Signs you need window mastic in Brockley Hill
A lot of older mastic was never designed to stay flexible. Once it has hardened, the frame’s movement tears it from the wall, leaving a hairline gap down one side.
People generally contact us after spotting something like this:
- Gaps between the frame and the inside reveal
- Untidy mastic left by window fitters
- Black, perished sealant on frames
- Cold air getting in at the frame edge
If you live in an older home near St Peter, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What to look for in a quote
- What happens if they find a problem under the old sealant
- What the cure time is
- What guarantee comes with the work
- How the joint is cleaned and prepared
What we do, step by step
Every visit runs the same way: we look at the joints together, protect the area around them, carry out the job and tidy away. It normally takes anything from an hour or two to a full day, depending on how many frames there are. In Brockley Hill, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- First we look at every frame and agree the list.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
Getting ready for the visit
- Mention any sign-in or site rules at work premises
- Tell us about access, such as stairs, a lift or high-level joints
- Keep pets and children clear of the area while we work
How to get a quote
We don’t publish a price list. Instead, we give you a clear quote for your job. To get started, ring 0345 464 0079 or email us.
Advice
Window mastic in Brockley Hill: local notes
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Headstone Manor (about 3.4 miles south-west) are a reminder that the area around Brockley 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.
Brockley Hill is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For site and facilities teams at buildings such as London Academy, larger buildings have plenty of frames, and the mastic around each one ages.
Brockley Hill is about 1 mile north of Stanmore, in Greater London. Homes, rented property, offices and hotels in Brockley Hill is covered for window mastic. The work is guaranteed for a year. 764 places in Greater London are on our list, large and small. London is on our list too, about 13 miles from Brockley Hill.
Work in HA7, HA8 and WD6 is quoted and booked the same way as anywhere else. Streets in the area include Wood Lane, Brockley Avenue and Pipers Green Lane, and we cover them all. We also cover Stanmore (1 mile south), Bushey Heath (2 miles west), Belmont (2 miles south-west), Harrow Weald (2 miles south-west) and Bushey (3 miles north-west). We also work in nearby towns such as London (13 miles south-east), City of Westminster (10 miles south-east), Marylebone (10 miles south-east), Kensington (10 miles south-east), St Pancras (11 miles south-east) and Shoreditch (12 miles south-east).
What’s near Brockley Hill
We work in homes and buildings around Abercorn Arms Public House, Aylward Primary School and Edgwarebury Park and the streets around them. For rail, the closest station is Elstree & Borehamwood station, roughly 1.8 miles north-east of the centre. Well-known places in the area include Royal National Orthopaedic Hospital (less than half a mile north-west) and Hilfield Castle (2.2 miles north-west). For a walk, there’s Darland's Lake and Edgware Way Grassland.
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Paint up to the joint, not over it
- Keep paint and stain on wooden frames in good order
- Wipe condensation off the frames
- Don’t aim a pressure washer at the joints
Keep sill grooves and drainage slots clear, so rain drains out rather than building up at the sealant.
Water trapped behind a failed joint can start rot in timber frames and sills. Once wood has rotted, it needs repair before it can be sealed, so early resealing is worth it.