Greater London · England
Window Mastic in Blendon
Mastic around window and door frames, sills and patio doors for homeowners, landlords and businesses in Blendon. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old mastic that has gone black or come away
- Draughts coming in around windows and doors
- Damp patches on the reveal after heavy rain
Window mastic for homes and businesses in Blendon
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. We work on aluminium frames, composite doors and uPVC windows, and people most often call us about cracked sealant at the sill ends and cold air getting in at the frame edge.
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, which is when draughts and damp patches appear in homes in Blendon.
You’re covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Location
- Blendon (DA5, DA15, DA6)
- Region
- Greater London
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How the job changes by surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A neat, narrow bead in a colour to match suits the frame.
Composite doors
Composite doors are normally hung in an uPVC-type frame, and the joint around it is sealed like a window. The bead is colour-matched to the frame.
What else we do in Blendon
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Your questions about window mastic in Blendon
Can parking be tricky for a visit in Blendon?
Parking in Blendon, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Is Blendon in your area for window mastic?
Yes. Our work covers London and the South East, and Blendon is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear quote.
Can you do the inside joint as well?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Do you remove the old sealant?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Will you leave a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
Do you have sealant for grey or black windows?
Yes, we choose a colour to suit the frame. Anthracite grey, black, brown and white cover most frames, with clear as an option.
Are you insured?
Yes. We are fully insured for domestic and commercial work.
Can landlords and businesses book you?
Yes. We work for homeowners, landlords, letting agents, businesses and hotels in Blendon.
Signs you need window mastic in Blendon
Some failures date back to when the windows were fitted. Mastic laid onto dusty, damp or crumbling surfaces didn’t grip properly, and it lets go sooner than it should.
The problems people usually mention when they call include:
- Old mastic that has gone black or come away
- A bead that doesn’t match the frame
- Mastic that has split away from the wall
- Cracked internal joints between frame and plaster
For landlords with property near Albany Park station, renewing tired window mastic between tenants heads off draught and damp complaints.
Comparing quotes
- Whether they’re fully insured
- How hidden problems are handled
- What the quote includes, VAT included or not
- How the surfaces are prepared before sealing
Aftercare tips
To keep the joints looking good and working properly:
- Keep solvents and bleach off the sealant
- Look round the frames every year or so
- Keep timber frames painted
- Make sure the drainage slots are not blocked
Wipe the frames with soapy water when you clean the windows, and keep solvents and harsh chemicals off the joint.
A failed joint lets water into the wall a little at a time. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
What we do, step by step
At the end, we look at the finished work together and tell you how long to leave it. The work normally takes a few hours for a handful of frames, longer for a whole house, depending on the size of the job. In a London area like Blendon, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- First we look at every frame and agree the list.
- The old mastic is cut out and the surfaces cleaned back.
- We fit backing rod in deep gaps so the sealant is the right depth.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- We clear up and check every joint is fully closed.
Getting ready for the visit
- Tell us about any previous sealing or DIY attempts
- For business premises, tell us about site rules or sign-in
- Mention any leaks or damp you’ve noticed
Ask for a quote
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or drop us an email.
Read more
Window mastic in Blendon: local notes
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Danson House (about 0.7 miles north) nearby, there’s older building stock in the area around Blendon as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
Homes close to St James the Great include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. Managing a site like Blackfen School for Girls? Then the mastic around its windows and doors needs looking after like any other building’s.
Blendon is about 1 mile south-east of Welling, in Greater London. If you need window mastic in Blendon, please phone 0345 464 0079 or drop us an email for a quick quote. We cover Greater London from our Crawley base, Blendon included. 764 places in Greater London are on our list, from the larger towns to small villages. London is on our list too, about 10 miles from Blendon.
We cover every part of DA5, DA15 and DA6 for window mastic. If you need window mastic at a property on Penn Lane, Hurst Road and Brook Lane or a nearby road, we can help. Blendon sits on or near the A221. We also cover Bexley (1 mile south-east), Crook Log (1 mile north), Welling (1 mile north-west), Upton (1 mile north-east) and Bexleyheath (1 mile north-east). We also work in nearby towns such as London (10 miles west), City of Westminster (13 miles west), Marylebone (13 miles north-west), Kensington (14 miles west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
Local landmarks in Blendon
Locally, jobs take us to homes and businesses close to Danson Park, The Royal Oak Public House and Hurst Primary School. The nearest railway station is Albany Park station, about 0.8 miles south. Other landmarks nearby include Metropolitan Police Museum (1.3 miles south-west) and Bexley Hospital (0.8 miles north-east). For a walk, there’s Wansunt Pit and Summer Hill.
What affects the cost of window mastic
Call for a quick quote. What matters most is:
- Any mould that needs treating
- The old material and how stubborn it is
- How easy the joints are to reach
- The number and length of the joints
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all play a part.
What to tell us for a quote
There’s no need for technical detail. Just tell us:
- The rough size of the job
- Where the job is, and your postcode
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, call 0345 464 0079 or send us an email.
When it is not the sealant
We will always be straight with you, so here’s what new sealant will not do:
- A sash or casement that will not close properly
- Worn gaskets, brush seals or a door that has dropped
- Soft or decayed wood in the frame
If you’re not sure, just ring 0345 464 0079 or send us an email and we will give you a straight answer before you book.
Where we work in Blendon
- uPVC windows
- Aluminium frames
- Window sills
- Patio & French doors
- Composite doors
- Timber windows & doors