Greater London · England
Glazing & conservatory sealant in Mill Hill, Greater London
Glazing silicone in Mill Hill from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Leaking glazing joints on a rooflight
- Glazing silicone that has cracked or come away
- A quick top-up bead that didn’t last
What we can’t put right
New sealant can’t fix everything, and we’d rather say so up front. It will not solve:
- Condensation trapped between two panes
- Structural problems with a conservatory roof
- Failed flashing around a conservatory
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think before you book.
What we seal
- Shower screens
- Conservatory frames
- Glass balustrade bases
- Rooflights
- Glass-to-frame joints
- Glass-to-glass joints
How we handle glazing silicone in Mill Hill
Conservatory leaks often start at a sealant joint, where glass meets frame or frame meets wall. We trace the leak to the joint and reseal it, and if it’s something sealant cannot fix, we’ll tell you. Typical jobs include a quick top-up bead that didn’t last and mouldy sealant around glass panels, across shower screens, glass-to-glass joints and glass-to-frame joints.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, letting in draughts and water.
There’s a 12-month guarantee on every job, whatever its size.
- Location
- Mill Hill (NW7, N20)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What we do, step by step
You do not need to clear the whole room or building, just the space around the work. We protect the rest, and the job takes a few hours for most jobs in most cases. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- We trace the leak and confirm it’s a sealant joint.
- We remove the old sealant carefully.
- We clean the glass and frame so the new silicone bonds.
- A neutral-cure glazing silicone is applied and tooled.
- Each joint is checked and, where possible, water-tested.
Before we arrive
- Clear items away from the joints we are working on
- For business premises, tell us about site rules or sign-in
- Where the joints are inside, avoid wetting them before we arrive
Get a quote
Need a quote? Please call 0345 464 0079 or send us an email with a few details. You will know what we plan to do, and what it will cost, before any work begins.
Advice
DIY sealant or a professional job?
The difference is mostly in the preparation and the 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.
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Also near Mill Hill
More services for Mill Hill
Work for landlords, hotels and businesses
We work for landlords and agents as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
If you manage several properties in or around Mill Hill, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
Surface by surface
Shower screens
Most shower screen leaks come from the wall or tray joint. Both are resealed with anti-fungal silicone.
Glass-to-glass joints
These joints are on show, so we take care to leave a neat bead.
Questions from Mill Hill
Do you cover Mill Hill for glazing silicone?
Yes. We work across London and the South East, and Mill Hill is part of that. You can ring 0345 464 0079 or email us and let us know what needs doing, and we’ll give you a clear price.
Is parking a problem for a job in Mill Hill?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly.
Do you reseal glass shower screens?
Yes, we do these often. The screen is resealed with anti-fungal silicone made for wet areas.
Can you replace a misted double-glazed unit?
No. A misted unit has failed inside and needs replacing by a glazier.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. For inside work, that normally means someone being in.
Can I do it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Do you remove the old sealant?
Always. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Where are you based?
We work from Crawley. Our applicators cover Mill Hill.
Why act early in Mill Hill
Leaks get worse, not better. Left, water can mark floors, damage plaster and rot timber, so it pays to deal with it early. In a flat in Mill Hill, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, along with when we can work on site. Ask us for a quote and we will go through it with you.
Why choose Mr Mastic in Mill Hill
- Over 20 years’ experience
- One-year guarantee on every job
- 180+ five-star Google reviews
- Any old sealant cut out fully, not covered over
See what affects the cost and customer reviews.
Frames and glazing around Mill Hill
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. In a converted house or block, who looks after the windows depends on the lease, so check that before booking.
Homes close to St Paul's Church include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. For landlords with property near Mill Hill Broadway station, a shower screen or conservatory joint that leaks is easier to reseal while the property is empty.
Mill Hill is about 1 mile north-east of Burnt Oak, in Greater London. Homes, rented property, offices and hotels in Mill Hill can book us for glazing silicone, old or new, large or small. Every job comes with our one-year guarantee. Our Greater London coverage runs to 764 places, Mill Hill among them. There’s also a page for London, about 10 miles away.
Here we cover the NW7 and N20 postcode area for glazing silicone. Streets in the area include Daws Lane, Byron Road and High Street. If you’re just outside Mill Hill, we cover The Hale (1 mile west), Burnt Oak (1 mile south-west), Grahame Park (1 mile south), Totteridge (2 miles north-east) and Edgware (2 miles west). Larger places within reach include London (10 miles south-east), City of Westminster (8 miles south-east), Marylebone (8 miles south-east), Kensington (8 miles south), St Pancras (8 miles south-east) and Shoreditch (9 miles south-east).
What’s near Mill Hill
Locally, jobs take us to homes and businesses close to Mill Hill School, Copthall School and Bittacy Hill Park, among other places. Other local landmarks include Francis Skaryna Belarusian Library and Museum (2 miles east) and Rising Sun pub (0.7 miles north-west). For rail, the closest station is Mill Hill Broadway station, roughly 1 mile south-west of the centre. Nearby you’ll also find Broadwalk Centre (2 miles west) and Francis Skaryna Belarusian Library and Museum (2 miles east). For a walk, there’s The Mill Field and Darland's Lake.
When to call us in Mill Hill
Dirt and grease stop silicone sticking. Where the joint wasn’t cleaned and degreased, the bead can peel away early.
It’s worth asking for a quote if you see:
- Failed joints on frameless glass
- Water running down inside the glass
- Glazing silicone that has cracked or come away
- A quick top-up bead that didn’t last
Mill Hill is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What to look for in a quote
- When the joint can take water or movement
- Whether they seal over old material or remove it
- Whether the sealant suits the joint
- What the quote includes, VAT included or not