Surrey · England
Window & door mastic in Bishopsgate, Surrey
Window and door frames in Bishopsgate need attention? We remove the old material, prepare the joints and seal them properly.
- Gaps left after new windows were fitted
- Water coming in at the bottom corners of a door
- Mastic that has split away from the wall
Window mastic in Bishopsgate, done properly
There are two joints on most windows. Outside, the mastic keeps rain out; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. Typical jobs include cold air getting in at the frame edge and damp patches on the reveal after heavy rain, across patio & French doors, composite doors and timber windows & doors.
Somewhere as small as Bishopsgate, older homes often have timber frames set in stone or brickwork. Not every older frame suits a modern silicone bead, so the sealant has to be chosen to suit the building.
Each job carries a 12-month guarantee.
- Where
- Bishopsgate (TW20)
- Wider area
- Surrey
- Guarantee
- One year on every job
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
uPVC windows
uPVC expands and contracts noticeably with temperature, so we use a flexible, low-modulus sealant. White is the usual colour, with brown, anthracite grey and black for coloured frames.
Window sills
Stone and concrete sills have their own joints, including the one between the sill and the frame above. We seal those with a sealant suited to masonry.
What we’re called out for in Bishopsgate
Every frame moves through the day. Sun on a frame makes it expand, and it contracts again overnight, while the masonry beside it stays put. If the sealant cannot stretch, it splits.
The most common problems we see are:
- Hard, cracked sealant around windows
- Mastic that is falling out in pieces
- Rain getting in at the frame or under the sill
- Sealant in the wrong colour for the frame
Managing a site like St John's Beaumont School? Then the mastic around its windows and doors needs looking after like any other building’s.
What to look for in a quote
- How the joint is cleaned and prepared
- Whether all the old sealant comes out first
- Who turns up on the day
- What the quote includes, VAT included or not
Keeping the joints in good condition
Looking after new joints is easy:
- Keep jet washers away from the mastic
- Keep drainage slots and sill grooves clear
- Walk round the house once a year and look at the joints
- Keep paint off silicone joints
Have a look at the joints once a year, ideally after winter. Cracks and lifting edges are easy to spot early.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. A new joint closes it up.
Bishopsgate homes and the weather
With historic houses such as Frogmore House (about 2.5 miles north) nearby, there’s older building stock in the area around Bishopsgate as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Homes close to Royal Chapel of All Saints include some older properties, and the joint between an old wall and a newer frame is generally the first place rain gets in. Letting a property close to Egham station? Then sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Bishopsgate is about 2 miles north-west of Egham, in Surrey. Anywhere in TW20, our applicators can take on window mastic. Across Surrey, we cover 395 places, Bishopsgate among them. You can also see our page for Reading, about 17 miles away.
Jobs for window mastic in TW20 is quoted and booked the same way as anywhere else. Local streets include Bishopsgate Road, Ridgemead Road and Wick Lane, all of which we cover. Other places close to Bishopsgate include Englefield Green (1 mile south-east), Egham Wick (1 mile south), Old Windsor (1 mile north), Wraysbury (2 miles north-east) and Egham (2 miles south-east). Larger places within reach include Guildford (13 miles south), Woking (9 miles south), Camberley (10 miles south-west), Epsom (15 miles south-east), Ewell (15 miles south-east) and Walton-on-Thames (9 miles south-east).
Near you in Bishopsgate
In Bishopsgate, that means homes and buildings near The Barley Mow Public House, Englefield Green Infant School and Nurseries and Windsor Great Park. For rail, the closest station is Egham station, about 1.8 miles east of the centre. Other landmarks nearby include Berkshire Yeomanry Museum (2.4 miles north-west) and Windsor Castle (3.2 miles north). For a walk, there’s St Ann's Hill and Virginia Water Lake.
Quotes for window mastic in Bishopsgate
We quote each job individually. These are the things that affect it:
- The amount of work
- The old material and how stubborn it is
- Whether the work is at height
- The product the joint needs
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote and we will talk you through it.
Helping us quote
Before you ask for a quote, have a think about:
- The problem you’ve noticed
- Whether it’s a home or a business
- How we’d reach the joints
- How many joints, rooms or windows are involved
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, phone 0345 464 0079 or email us.
What sealant work can’t fix
In fairness, there are a few things sealant won’t fix:
- Rotten timber, which needs a joiner first
- Penetrating damp from a failed cavity tray or render
- A failed sealed unit that has misted up
If you are not sure, just call 0345 464 0079 or send us an email and we will give you a straight answer before booking.
Joints and surfaces we work on
- Composite doors
- Patio & French doors
- Timber windows & doors
- uPVC windows
- Window sills
- Aluminium frames
Towns and villages near Bishopsgate
Also in Bishopsgate
The process
Good joint work is mostly preparation, and we don’t rush it. Joints are cleaned back and dried before anything new goes in. In total, it usually takes most of a day for a typical house, less for a few frames. Somewhere like Bishopsgate needs a little journey planning: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- We check each frame and agree which ones need doing.
- Next the failed sealant is cut away and the joint cleaned.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
Preparing for the visit
- Tell us if parking is tricky
- Try not to wet indoor joints just before the visit
- Tell us about access, such as stairs, a lift or high-level joints
How to get a quote
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job, and we’ll come back to you with a quote.
Advice
Bishopsgate questions
Do you work for landlords with property near Egham station?
Yes, we work for landlords and letting agents. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before work begins.
Can you do window mastic in Bishopsgate?
Yes, Bishopsgate is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or send us an email with a few details of the job, and we will send you a clear quote.
Is it worth trying it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
Will the old sealant be removed?
Always. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Do you guarantee window mastic?
Yes, with our 12-month guarantee. Keeping drainage clear and checking the joints yearly helps them last.
Will there be a smell?
It depends on the product. Some products have a noticeable smell, others very little.
Can new window sealant be painted?
It depends on the sealant. Some hybrid sealants can be painted; silicone can’t. Mention any painting plans before any work starts.
Can you seal over the old sealant?
No. New silicone will not bond to old silicone, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Landlord and commercial work in Bishopsgate
If you manage several properties in or around Bishopsgate, several properties can go on one quote. Send us the addresses and the work at each, and pictures by email help.
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.