Greater London · England
Fortis Green Sand Mastic
Our applicators work in Fortis Green on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Gaps between timber frames and stone or brick
- Mastic that needs renewing before redecorating
- Cement or filler used on old window joints that has cracked
How we handle sand mastic in Fortis Green
A silicone bead around a sash window can look out of place and is not always the right material. Sand mastic is the traditional choice, and we can replace one with the other. If you have gaps round a timber door in stone or brick and open joints round the window box, we can put it right, whatever the surface.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
The work is covered for a year after we finish. If there’s a problem with it, please ring 0345 464 0079 or drop us an email.
- Place
- Fortis Green (N10, N2, N6)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
When something else is needed
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Broken panes
- Crumbling stone or brickwork round the window
- Timber that has rotted
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think.
Joints and surfaces we work on
- Brick reveals
- Period & listed homes
- Stone surrounds
- Tenement windows
- Timber door frames
- Sash and case windows
Why it’s worth doing now in Fortis Green
Not every filler suits an old window surround. Sand mastic is the like-for-like choice and that can be important for listed homes. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
Why choose Mr Mastic in Fortis Green
- Anti-fungal sanitary silicone in wet areas
- Domestic, commercial and hotel work
- Approved under the ARBOMaster scheme
- Over 20 years’ experience
Take a look at what affects the cost or what customers say.
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, 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.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so just mention it when you contact us.
Your questions about sand mastic in Fortis Green
Can you do sand mastic in Fortis Green?
Yes. Our work covers London and the South East, and Fortis Green is part of that. You can ring 0345 464 0079 or email us and tell us what needs doing.
Can parking be tricky for a visit in Fortis Green?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
How do I get a quote for sand mastic in Fortis Green?
Size, access and the old material all affect the cost. Ask us for a quote and we will talk you through it.
Where is Mr Mastic based?
Our base is in Crawley, and we cover South East England, London and all of Scotland.
Can tenants book the work?
Yes, but check with your landlord or agent first. Landlords are often happy for the work to be arranged.
Can you quote for more than one area?
Yes. More than one area can be quoted together.
Do you work for landlords and businesses?
Yes, we do. We work in homes, commercial premises and hotels, and we are fully insured.
Can sand mastic be painted?
Sand mastic is normally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Landlords, agents and businesses in Fortis Green
We also work for property managers and facilities teams. We can quote a run of properties together, and we’re fully insured for the work.
Landlords and letting agents in Fortis Green can book us as well as householders. Sealant work between tenants keeps a property looking cared for.
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Avoid heavy scraping on the mastic joint
- Clear gutters so water does not pour onto the windows
- Avoid patching sand mastic with silicone
- Leave the new mastic unpainted
Leave the new mastic unpainted, as traditional guidance advises. If you’re redecorating, ask us first.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall so early renewal protects both.
Nearby places to Fortis Green
What else we do in Fortis Green
What we do, step by step
When we arrive, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before we start. Most jobs take anything from a few hours to a full day, depending on how many windows. In Fortis Green, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- The surface is finished to suit the stone or brick.
How to prepare
- Let us know about parking restrictions
- Let us know about stairs, lifts or work at height
- Try not to wet indoor joints just before the visit
How to get a quote
We quote each job on its own. Simply call 0345 464 0079 or send us an email and describe the job, and photos are welcome.
Advice
Windows and doors in Fortis Green
Historic houses like Heath Hall (about 1.4 miles south-west) are a reminder that the area around Fortis Green has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
If you let a flat or house near Alexandra Palace station, older sash windows in a rental need their mastic kept sound to keep the weather out. Schools such as Fortismere School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s. As a London address, Fortis Green can be tricky for parking: let us know about parking bays, permits or a driveway.
Fortis Green is about 1 mile south-east of Finchley, in Greater London. Fortis Green gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Fortis Green is one of 764 towns and villages in Greater London where we work. London is on our list too, about 7 miles from Fortis Green.
Postcode districts we cover here for sand mastic: N10, N2 and N6. Streets in the area include Hill Road, Durham Road and Steeds Road, all of which we cover. You’ll find Fortis Green on the A504, which makes it straightforward to reach. Other places close to Fortis Green include Muswell Hill (1 mile east), East Finchley (1 mile west), Highgate (1 mile south), Crouch End (1 mile south-east) and Hampstead Garden Suburb (2 miles south-west). Further out, we also cover London (7 miles south), City of Westminster (5 miles south), Marylebone (5 miles south), Kensington (7 miles south), St Pancras (5 miles south) and Shoreditch (6 miles south-east).
Local landmarks in Fortis Green
Typical jobs here are in homes near Tollington School, Cherry Tree Wood and The Clissold Arms, among other places. The nearest railway station is Alexandra Palace station, roughly 1.4 miles east of the centre. Well-known places in the area include Kenwood House (1.6 miles south-west) and Grand Arcade (1.8 miles north-west). The countryside around Fortis Green includes Highgate Hill and Glebelands Local Nature Reserve.
Quotes for sand mastic in Fortis Green
There’s no set price list. The quote depends on:
- The amount of work
- Any mould that needs treating
- Access and height
- Which sealant suits the joint
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs. Ask us for a quote and we’ll explain what it covers.
What to tell us for a quote
There’s no need for technical detail. It helps if you can tell us:
- Whether it has been sealed before
- The problem you’ve noticed
- Pictures of the joints, sent by email
- Where the job is, and your postcode
We do not publish a price list. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or drop us an email.