Greater London · England
Glazing Silicone in St John's Wood
Glazing silicone for conservatories, rooflights, glass panels and shower screens in St John's Wood, with a 12-month guarantee on every job. Ask us for a quote.
- Black or yellowed silicone on glass joints
- Rooflight joints letting water in
- A quick top-up bead that didn’t last
Glazing silicone for homes and businesses in St John's Wood
Frameless shower screens rely on sealant to keep water in. The joint down the wall and the one along the tray are common leak points and both get fresh anti-fungal silicone. If you have silicone pulling away from the glass and water running down inside the glass, we can help, whatever the surface.
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, which is when draughts and damp patches appear in homes in St John's Wood.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- St John's Wood (NW8, NW6, NW3)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How to look after the new joints
Looking after new joints is easy, and it makes a real difference:
- Clean glass with a mild cleaner and a soft cloth
- Open vents or windows to let moisture out
- Look over the glazing joints once a year
- Keep conservatory gutters clear of leaves
Follow the cure time we give you before the joints get wet so the silicone can set properly. After that, clean glass with a mild cleaner.
Cracked glazing silicone means the joint has failed. Resealing now is a small job, compared with repairing damaged frames or plaster.
Windows and doors in St John's Wood
With historic houses such as Winfield House (about 0.6 miles south-east) nearby, there’s older building stock in the area around St John's Wood 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. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Managing a site like George Eliot Primary School? Then the mastic around its windows and doors needs looking after like any other building’s. St John's Wood is in London, so parking needs planning: let us know about parking bays, permits or a driveway. In the older streets around Church of All Souls, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
St John's Wood is about 1 mile south of Hampstead, in Greater London. Every kind of property in St John's Wood is covered for glazing silicone. Every job comes with our one-year guarantee. St John's Wood is one of 764 towns and villages in Greater London we cover for glazing silicone.
Every address in NW8, NW6 and NW3 is within our area for glazing silicone, from the main roads to the quietest streets. If you need glazing silicone at a property on The Lane, Hall Road and Hill Road or anywhere close by, our applicators can take on the job. With the A5205 close by, St John's Wood is easy for our applicators to reach for glazing silicone. We also cover South Hampstead (1 mile north), Swiss Cottage (1 mile north), Primrose Hill (1 mile north-east), Lisson Grove (1 mile south) and Haverstock (1 mile north-east). Larger places within reach include London (4 miles south-east), Kensington (3 miles south-west), St Pancras (3 miles east), Shoreditch (4 miles east), Walthamstow (7 miles north-east) and Hoxton (4 miles east).
Around St John's Wood
In St John's Wood, that means homes and buildings near Cecil Sharp House, Primrose Hill and Arnold House School. Nearby too are Quintin Kynaston Community Academy (within half a mile north-west) and Cafe Med pub (within half a mile north-west). There’s a railway station in St John's Wood itself: South Hampstead station. A little further out are Hospital of St John and St Elizabeth (less than half a mile south) and Montfichet's Tower (3.5 miles south-east). Not far away are The Long Water and Primrose Hill.
Questions from St John's Wood
I let a flat near South Hampstead station. Can you help?
Yes, we work for landlords and letting agents. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can you do glazing silicone in St John's Wood?
Yes. Our work covers London and the South East, and St John's Wood is part of that. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
Can I choose the sealant colour?
In most cases you can choose. We’ll explain which colours are available and agree one before work begins.
Can I add another job to the visit?
Yes. Just list everything you need and we’ll quote it together.
Does someone need to be in?
That depends on where the joints are. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.
When is the sealant fully cured?
Cure times vary by product and the conditions. We tell you how long to leave it before we go.
How long will you be here?
That depends on how much there is to do, but as a guide it takes a few hours for most jobs. We’ll tell you when we quote.
Will you leave a mess?
We keep the work tidy. Nearby surfaces are protected.
Nearby places to St John's Wood
What else we do in St John's Wood
DIY sealant or a professional job?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Quotes for glazing silicone in St John's Wood
Call for a quick quote. The main things that affect it are:
- The amount of work
- Access and height
- How many rooms, windows or areas are involved
- How much old sealant there is and how hard it is to remove
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
What we need to know
When you contact us, these details help:
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
- Any previous sealing or DIY work
- How we’d reach the joints
To get a quote, call 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You will have a clear quote before any work starts.
What happens on the day
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for most jobs, and the area is left clean. In St John's Wood, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at the glazing and agree which joints need resealing.
- We cut away the failed silicone.
- We clean and prepare the joint.
- New glazing silicone goes in and is finished neatly.
- The joints are checked before we leave.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- Clear the area around the work
- Let us know about parking restrictions
Getting a quote
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.
Read more
Why act early in St John's Wood
Replacing a conservatory roof is major work. Where the water is getting in through sealant, resealing is far simpler. If it’s the roof itself, we will tell you. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
Why choose Mr Mastic in St John's Wood
- A 12-month guarantee on all work
- Quality sealants from Arbo and Everbuild
- White, clear, grey or coloured to suit, where the product allows
- Old sealant always removed completely
Read how sealant jobs are priced and customer reviews.
What sealant work cannot fix
To be straight with you, there are a few things sealant won’t fix:
- Failed flashing around a conservatory
- Rotten or badly damaged frames
- Glass that needs replacing
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before booking.
Joints and surfaces we work on
- Glass balustrade bases
- Rooflights
- Glass-to-glass joints
- Conservatory frames
- Shower screens
- Glass-to-frame joints
Landlord and commercial work in St John's Wood
Letting agents often deal with us directly. Tell us the address, the job and how access works.
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.