Greater London · England
Sand mastic for sash & case windows in Herne Hill, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Herne Hill, with a one-year guarantee on every job. Ask us for a quote.
- Draughty sash windows at the surround
- Mastic worn away on windows facing the weather
- Silicone on a period window that looks wrong
Sand mastic for homes and businesses in Herne Hill
A silicone bead around a sash window can look out of place and does not suit the building. Sand mastic is the traditional choice and we can swap the silicone for it. We work on sash and case windows, timber door frames and brick reveals, and common reasons people get in touch are mastic dropping out of the joint and patchy fillers round a sash window.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease normally says who is responsible for the windows, so it’s worth checking before booking, and access in Herne Hill is something to talk through when you book.
Each job carries a 12-month guarantee.
- Place
- Herne Hill (SE22, SW2, SE24)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How we quote for sand mastic
Call for a quick quote. The main things that affect it are:
- How easy the joints are to reach
- The type of sealant required
- Whether there’s mould to deal with
- When we can work, for business premises
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, phone 0345 464 0079 or send us an email and we’ll give you an honest view and a quote.
What to tell us for a quote
You don’t need to know the technical terms. It helps if you can tell us:
- Where the job is, and your postcode
- Roughly how big the job is
- The type of property
- What’s wrong with the joints now
For a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. We’ll send you a clear quote before any work starts.
How the job changes by surface
Stone surrounds
Stone openings are rarely perfectly straight, so the gap is not the same all the way round. Sand mastic is shaped by hand to suit.
Period and listed homes
A traditional finish suits a period property, and sand mastic is one of them.
How it works
On the day, we start by going over the job with you. Surfaces next to the work are protected before work begins. Most jobs take a few hours for a single window, longer for several. In Herne Hill, 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.
- Old mastic and any loose material are raked out.
- 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
- Keep pets and children clear of the area while we work
- Move anything stored near the joints
- Tell us about any water getting in
How to get a quote
If you are in Herne Hill and need sand mastic, call 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
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Also near Herne Hill
More services for Herne Hill
For landlords and businesses
We work for landlords and agents as well as householders. Resealing between tenancies keeps a property looking cared for.
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Why it’s worth doing now in Herne Hill
If you are redecorating, renew the mastic first. Paint over cracked mastic won’t stop the gaps and traditional guidance is to leave the new mastic unpainted. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Herne Hill, the repair is bigger than a sealant job.
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
What you get with us
- Domestic, commercial and hotel work
- 20+ years of sealant experience
- Tidy, careful work
- Arbo and Everbuild products
Read how sealant jobs are priced and customer reviews.
Herne Hill: your questions answered
Can you help a landlord with a rental near North Dulwich station?
Yes. We work for landlords and agents as well as homeowners. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear quote.
Can you do sand mastic in Herne Hill?
Yes. Our work covers London and the South East, and Herne Hill is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing.
Should I use sand mastic or silicone?
It depends on the window. On many period windows, sand mastic looks right and suits the building and newer frames usually get a flexible sealant.
Can you match the sealant colour?
Yes. Sealants come in white, clear, grey and other colours, and we’ll agree it with you first.
How long does sand mastic take to go off?
A skin forms quite soon, but full hardening takes longer. We will tell you what to expect for your job.
How do I get a quote for sand mastic in Herne Hill?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or send us an email and tell us what needs doing and where.
Which products do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Where are you based?
Our base is in Crawley, West Sussex, and we work across South East England, London and Scotland.
When something else is needed
Sealant is not the answer to every problem, and we’ll tell you before we start. Sealant will not put right:
- Decisions on consent for listed homes
- Broken panes
- Masonry that needs repairing
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
What we seal
- Timber door frames
- Stone surrounds
- Sash and case windows
- Brick reveals
- Period & listed homes
- Tenement windows
Aftercare tips
To keep the joints looking good and working properly:
- Leave the new mastic unpainted
- Find out about consent before window work on a listed home
- Keep sills and gutters clear so water drains away
- Inspect the joints round the windows every year or so
When preparing windows for paint, take care around the mastic. Hard scraping can loosen it.
Crumbling mastic lets rain into the joint. It can soak into the frame and the surrounding masonry so early renewal protects both.
Sand mastic in Herne Hill: local notes
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Kingswood House (about 1.7 miles south) nearby, there’s older building stock in the area around Herne Hill as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
If you let a flat or house near North Dulwich station, cracked sand mastic around sash windows lets in the draughts tenants complain about. Managing a site like Judith Kerr Primary School? Then its window and door frames need their mastic kept sound, just like a home’s. If you live in an older home near Saint Faith's, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Herne Hill is about 3 miles south of London, in Greater London. If you need sand mastic in Herne Hill, it’s easy to get a quote: please phone 0345 464 0079 or drop us an email. We are based in Crawley and cover Greater London, Herne Hill included. Our Greater London coverage runs to 764 places, and Herne Hill is one of them.
Our applicators cover all of the SE22, SW2 and SE24 postcode area for sand mastic. If you need sand mastic at a property on Jelf Road, Dewey Lane and Talma Road or a nearby road, we can help. Herne Hill sits on or near the A204 and A2214, which makes travel easy. We also cover Dulwich Village (1 mile south-east), East Dulwich (1 mile north-east), Dulwich (1 mile south-east), Denmark Hill (1 mile north) and Camberwell (1 mile north). We also work in nearby towns such as London (3 miles north), City of Westminster (5 miles north-west), Marylebone (5 miles north-west), Kensington (6 miles north-west), St Pancras (5 miles north) and Shoreditch (5 miles north).
Around Herne Hill
In Herne Hill, that means homes and buildings near The Charter School, Half Moon pub and Belair Park, among other places. There’s a railway station in Herne Hill itself: North Dulwich station. Well-known places in the area include Surrey Quays Shopping Centre (3.5 miles north-east) and House of Dreams Museum (0.7 miles north-east). For a walk, there’s Battersea Park Lake and Knight's Hill.