Greater London · England
Window Mastic in Telegraph Hill
Window mastic for Telegraph 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
- Mastic that is falling out in pieces
- Draughts coming in around windows and doors
About our window mastic in Telegraph Hill
The mastic around a window or door seals the gap between the frame and the wall. When it cracks, hardens or pulls away, draughts and rain get in. Our applicators cut it out and replace it with a flexible, weatherproof sealant. We work on uPVC windows, patio & French doors and timber windows & doors, and the jobs we see most are whistling draughts around closed windows 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. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
Every job is covered by our one-year guarantee, wherever you are in Greater London.
- Place
- Telegraph Hill (SE4, SE15, SE14)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Landlords, agents and businesses in Telegraph Hill
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
Do you need window mastic in Telegraph Hill?
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. A sealant that cannot keep up eventually tears.
Signs it’s time to call us include:
- White mastic on grey or black frames
- Old mastic that has gone black or come away
- Cracked or shrunken mastic around the frame
- Whistling draughts around closed windows
Managing a site like Haberdashers' Hatcham College? Then its window and door frames need their mastic kept sound, just like a home’s.
What your quote should include
- Whether they seal over old material or remove it
- Who does the work, and how experienced they are
- Whether they’re fully insured
- What happens if the job turns out different
More services for Telegraph Hill
Aftercare tips
After the cure time, these simple habits help:
- Keep timber frames painted
- Clear any debris from frame drain holes
- Avoid harsh chemicals near the mastic
- Don’t aim a pressure washer at the joints
Try not to touch the new joint while it cures, for as long as we advise. Don’t point a pressure washer at the joints.
On timber windows, water behind the joint can lead to rot. Rotten timber needs a joiner, not a sealant, so it pays to reseal before that happens.
Why deal with it now?
Redecorating is a good moment to renew the mastic. Fresh joints finish the job neatly, and it’s easier while the walls are being worked on anyway. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Telegraph Hill, the repair is bigger than a sealant job.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all play a part.
Why choose Mr Mastic in Telegraph Hill
- A choice of colours where the product allows
- Neat joints and a tidy finish
- Every job guaranteed for a year
- An ARBOMaster approved applicator
Take a look at what affects the cost or our reviews.
Common questions in Telegraph Hill
Is parking an issue for window mastic in Telegraph Hill?
Parking in Telegraph Hill, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Do you cover Telegraph Hill for window mastic?
Yes. Our work covers London and the South East, and Telegraph Hill is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Where do you work from?
We’re based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
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.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Will resealing my frames help with draughts?
If the draught is coming in around the frame, yes. If it’s through the window’s own seals or a hinge, that’s a different fix, and we’ll say so.
Are you fully insured?
Yes. We’re fully insured, and we’ve been doing sealant work for more than 20 years.
Is it worth trying it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Should I try it myself first?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
What happens on the day
Every visit runs the same way: we check the joints, protect the area around them, do the work and tidy away. Most jobs take most of a day for a typical house, less for a few frames. In a London area like Telegraph Hill, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- We check how each frame can be reached safely.
- All the failed sealant is cut away, 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
- Mention any parking rules near the property
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about earlier repairs to the joints
Ask for a quote
Want a quote for window mastic? Please call 0345 464 0079 or email us with a few details. We’ll explain what we’d do and give you a clear price before any work starts.
Advice
Frames and glazing around Telegraph Hill
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. In a converted house or block, who looks after the windows depends on the lease, so check that before you book.
For an older house near a landmark such as St Catherine's Hatcham, frames set in older brick or stone need a sealant that suits the wall as well as the frame. For landlords with property near Brockley station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Telegraph Hill is about 1 mile south-west of New Cross, in Greater London. Jobs in Telegraph Hill get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Across Greater London, we cover 764 places, Telegraph Hill among them.
Here we cover the SE4, SE15 and SE14 postcode area for window mastic. If you need window mastic at a property on Mona Road, Pepys Road and Kitto Road or anywhere close by, our applicators can take on the job. We also cover the places around Telegraph Hill: Nunhead (1 mile south-west), New Cross (1 mile north-east), Peckham (1 mile north-west), St Johns (1 mile east) and Brockley (1 mile south-east). Further out, we also cover London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (7 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north).
Near you in Telegraph Hill
Typical jobs here are in homes near Fordham Park and The Brockley Barge pub and the streets around them. Telegraph Hill has its own railway station: Brockley station. Other landmarks nearby include Southwark Adult Education Institute (0.6 miles north-west) and Lewisham Shopping Centre (1.4 miles east). Not far away are St. James's Park Lake and New Cross Gate Cutting.
When it is not the sealant
Sealant isn’t the answer to every problem, and we will tell you before we start. Sealant will not put right:
- Rotten timber, which needs a joiner first
- Faulty window hardware
- Misting between the panes of a double-glazed unit (that needs a new unit)
If you’re not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer.
Joints and surfaces we work on
- uPVC windows
- Aluminium frames
- Timber windows & doors
- Patio & French doors
- Composite doors
- Window sills