Greater London · England
Window & door mastic in Bishopsgate, Greater London
Window mastic in Bishopsgate from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Leaking joints at the ends of sills
- Water coming in at the bottom corners of a door
- White mastic on grey or black frames
How we handle window mastic in Bishopsgate
Behind a thin line of old mastic there’s sometimes a deep void. Filling it with sealant alone leaves a joint that can’t move properly, so deep gaps get backing rod first. The sealant then grips the two sides it should. Typical jobs include leaking joints at the ends of sills and damp patches on the reveal after heavy rain, on window sills, composite doors and timber windows & doors.
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, in Bishopsgate as anywhere.
The work is covered for a year after we finish. If anything is not right with it, ring 0345 464 0079 or email us.
- Place
- Bishopsgate (E1, EC2A, EC1Y)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Can I do it myself?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Also near Bishopsgate
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Your questions about window mastic in Bishopsgate
Is parking an issue for window mastic in Bishopsgate?
Parking in Bishopsgate, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Do you work for landlords with property near London Liverpool Street station?
Yes, landlords and agents are among the people we work for. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Should I try DIY first?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Do you do commercial work?
Yes. We have worked for hotels, offices and other businesses.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint.
Where are you based?
Our base is Crawley, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Is it messy?
We keep the work tidy. Nearby surfaces are protected.
Do you remove the old sealant?
Yes, always, and completely. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
Landlord and commercial work in Bishopsgate
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.
Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
What the job involves on each surface
Patio & French doors
The joints around patio doors run a long way, top, sides and threshold. Most leaks start at the bottom corners, so we pay close attention there.
Aluminium frames
Coated aluminium needs a compatible sealant. Neutral-cure sealant is the safe choice.
Why it’s worth doing now in Bishopsgate
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Bishopsgate, the repair is bigger than a sealant job.
What you pay reflects the work, not guesswork. That’s why we ask a few questions first.
Why book with us
- Colour picked to suit the job
- Approved under the ARBOMaster scheme
- Full insurance on every job
- Old sealant always removed completely
Take a look at what affects the cost and what customers say.
How the visit works
Most of a good job is in the preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes most of a day for a typical house, less for a few frames. In a London area like Bishopsgate, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- First we look at every frame and agree the list.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Every joint is checked before we leave.
How to prepare
- Tell us if parking is tricky
- Let us know about stairs, lifts or work at height
- Mention any leaks or damp you’ve noticed
Getting a quote
Getting a quote is simple: let us know the job and the location, and roughly how big it is. A few photos by email make the job easier to understand, and we’ll take it from there.
Related advice
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Paint up to the joint, not over it
- Avoid blasting the frames with a pressure washer
- Use gentle cleaners on frames and sealant
- Keep solvents and bleach off the sealant
Keep sill grooves and drainage slots clear, so water can run away instead of sitting against the joint.
Water trapped behind a failed joint can start rot in timber frames and sills. Rotten timber needs a joiner, not a sealant, so early resealing is worth it.
What sealant work can’t fix
To be straight with you, there are a few things sealant won’t fix:
- Penetrating damp from a failed cavity tray or render
- Worn gaskets, brush seals or a door that has dropped
- Rotten timber, which needs a joiner first
If you are not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer.
Joints and surfaces we work on
- Patio & French doors
- uPVC windows
- Window sills
- Composite doors
- Timber windows & doors
- Aluminium frames
Windows and doors in Bishopsgate
Historic houses like Mansion House (about 0.4 miles south-west) are a reminder that the area around Bishopsgate has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book.
If you live in an older home near Church of St Ethelburga, frames set in older brick or stone need a sealant that suits the wall as well as the frame. If you let a flat or house near London Liverpool Street station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. For site and facilities teams at buildings such as The London School of Barbering, larger buildings have plenty of frames, and the mastic around each one ages.
Bishopsgate is about 1 mile north-east of London, in Greater London. Homes, rented property, offices and hotels in Bishopsgate is covered for window mastic, old or new, large or small. Every job comes with our one-year guarantee. Bishopsgate is one of 764 towns and villages in Greater London we cover.
Work in E1, EC2A and EC1Y is quoted and booked the same way as anywhere else. Local streets include Bush Lane, Swan Lane and Love Lane, all of which we cover. You will find Bishopsgate on the A3 and A10, which makes it straightforward to reach. We also cover Aldgate (1 mile south-east), Spitalfields (1 mile east), City of London (1 mile west), Tower Hill (1 mile south) and Whitechapel (1 mile east). Within a short drive, we also cover City of Westminster (3 miles west), Marylebone (3 miles west), Kensington (5 miles west), Walthamstow (5 miles north-east), Hampstead (5 miles north-west) and Ruislip (15 miles west).
Around Bishopsgate
Locally, jobs take us to homes and businesses close to Bishopsgate Institute Special Collections and Archives, St Mary-at-Hill and The Aldgate School. Also close by are White Hart pub (under half a mile north-east), Central Foundation Boys' School (0.7 miles north) and Finsbury Circus (less than half a mile north-west). There’s a railway station in Bishopsgate itself: London Liverpool Street station. Well-known places in the area include London Bridge Hospital (0.7 miles south) and Gabriel's Wharf (1.2 miles south-west). The countryside around Bishopsgate includes St. James's Park Lake and Tower Hill.