Greater London · England
Sand mastic for sash & case windows in Church End, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Church End, backed by a 12-month guarantee. Ask us for a quote.
- Gaps where the frame meets the masonry
- Wind and rain getting in round a sash window
- Mastic round period door frames that has failed
How we handle sand mastic in Church End
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. We rake it out and renew it so the surround looks right again. We are often asked to deal with open joints round the window box and weathered mastic on the most exposed windows, on sash and case windows, stone surrounds and period & listed homes.
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, in Church End as anywhere.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Location
- Church End (N3, N12, NW7)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Signs you need sand mastic in Church End
Age is the main cause. Sand mastic is a maintenance item like any pointing and how long it lasts depends on the weather it faces.
Keep an eye out for any of the following:
- Open joints round the window box
- A silicone bead on a sash window that spoils the look
- Cracked mastic round a front door frame
- Patchy fillers round a sash window
For an older house near a landmark such as St Margaret's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Comparing quotes
- Is VAT in the price?
- How long the guarantee is
- When the joint can take water or movement
- Which colour the sealant will be
Nearby places to Church End
Also in Church End
DIY versus a professional finish
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so tell us about it when you ask for a quote.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
What we can’t put right
Before you book, it’s worth knowing the limits too:
- Decisions on consent for listed homes
- Cracked or broken glass
- Decayed frames that need repair
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before booking.
Surfaces we seal
- Stone surrounds
- Sash and case windows
- Timber door frames
- Brick reveals
- Tenement windows
- Period & listed homes
How it works
On the day, we look over the joints with you first, so you know exactly what we’re doing. Surfaces next to the work are protected before work begins. The work normally takes a few hours for a single window, longer for several. For a job in Church End, parking and access are the things to plan: let us know about parking, the floor we will be working on and any lift or shared entrance.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- 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
- Keep children and pets away from the work area
- Try not to wet indoor joints just before the visit
- Tell us about any previous sealing or DIY attempts
Getting a quote
There’s no standard price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or drop us an email.
Related advice
Why deal with it now?
Draughts round a sash window are not always the sashes. Open mastic joints round the box can let air in, and renewing the mastic closes them. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Church End, the repair is bigger than a sealant job.
What you pay reflects the work, not a rough estimate. That is why we ask a few questions first and agree the price before starting.
Why Church End clients choose us
- An ARBOMaster approved applicator
- 20+ years of sealant experience
- Rated 4.9 stars on Google
- Fully insured
Take a look at what affects the cost or our reviews.
What affects the cost of sand mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- How many areas need sealing
- Whether there’s mould to deal with
- The amount of work
- The product the joint needs
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
What we need to know
Photos help, but a description is a good start. Try to tell us:
- The address or postcode of the job
- Photos by email, if that’s easy
- What’s wrong with the joints now
- If it’s domestic, commercial or a hotel
Want a quote for sand mastic? Please ring 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Church End: your questions answered
Do you work for landlords with property near New Southgate station?
Yes. We work for landlords and letting agents as well as homeowners. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
Can you do sand mastic in Church End?
Yes, Church End is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we’ll send you a clear quote.
How long will you be here?
Typically it takes anything from a few hours to a full day, depending on how many windows. Larger jobs naturally take longer, and we will tell you how long to expect.
Is the work guaranteed?
All our work has a one-year guarantee.
Is it possible to take out silicone and use sand mastic instead?
Normally, yes. With the silicone removed and the joint cleaned we point it with sand mastic.
Can new sealant go over the old?
No, because it fails. We remove every bit of old sealant first, so the new sealant bonds properly.
Will the old sealant be removed?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Are you ARBOMaster approved?
Yes. Mr Mastic is an ARBOMaster approved applicator.
What sand mastic looks like in Church End
With historic houses such as Heath Hall (about 2.1 miles south-east) nearby, there’s older building stock in the area around Church End as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
Church End is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. Rented homes near New Southgate station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out.
Church End is about 1 mile west of Finchley, in Greater London. Every kind of property in Church End can book us for sand mastic. The work is guaranteed for a year. Church End is one of 764 places in Greater London we cover. Our London page covers work nearby (8 miles or so).
Every address in N3, N12 and NW7 is within our area for sand mastic. Streets in the area include The Avenue, Cyprus Road and Gordon Road, and we cover them all. We also cover the places around Church End: Finchley (1 mile east), Woodside Park (1 mile north), North Finchley (1 mile north-east), Friern Barnet (2 miles north-east) and Oakleigh Park (2 miles north-east). Larger places within reach include London (8 miles south-east), City of Westminster (6 miles south), Marylebone (6 miles south), Kensington (7 miles south), St Pancras (6 miles south-east) and Shoreditch (7 miles south-east).
Near you in Church End
Locally, jobs take us to homes and businesses close to Victoria Park, Francis Skaryna Belarusian Library and Museum and Christ's College and the streets around them. You will also find The Elephant Inn (0.9 miles north-east) and Woodhouse College (1.2 miles north-east). The closest station to Church End is New Southgate station, about 2.3 miles east of the centre. A little further out are Jewish Museum - Finchley (0.5 miles south) and Finchley Memorial Hospital (0.7 miles east). Green spaces nearby include Darland's Lake and Lakeside Nature Reserve.
For landlords and businesses
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can be quoted together.