Greater London · England
Sand mastic for sash & case windows in Longlands, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Longlands, backed by a one-year guarantee. Call for a quick quote.
- Cracked mastic round a front door frame
- Wind and rain getting in round a sash window
- Crumbling sand mastic round a window
Sand mastic for homes and businesses in Longlands
Traditional burnt sand mastic that sits naturally against stone and brick. It suits period and listed homes, where modern sealant can look out of place. Common call-outs are for failed mastic on an exposed elevation and gaps where the frame meets the masonry, across brick reveals, stone surrounds and sash and case windows.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking, and access in Longlands is something to talk through when you book.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Place
- Longlands (DA15, DA14, SE9)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Your questions about sand mastic in Longlands
Is parking an issue for sand mastic in Longlands?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
I let a flat near New Eltham station. Can you help?
Yes, we work for landlords and letting agents. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
How long will you be here?
That depends on how much there is to do, but most jobs take anything from a few hours to a full day, depending on how many windows. We will tell you when we quote.
Do I need permission for sand mastic on a listed building?
Checking first is sensible. Ask your local planning authority whether consent is needed for work on a listed home or in a conservation area.
What guarantee comes with the work?
You get our one-year guarantee on every job.
How do I get a quote for sand mastic in Longlands?
It depends on the job, so we quote each one individually. For a quick quote, ring 0345 464 0079 or drop us an email and tell us what needs doing and where.
What do you put in the joint?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Do you do commercial work?
Yes. Larger jobs can be planned room by room or area by area.
How it works
You do not need to clear the whole room or building before we come, only the area right around the joints. We protect the rest, and the job takes a few hours per window, depending on the condition of the joints for a typical job. In Longlands, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We look at the surrounds with you and agree the joints to renew.
- 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.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Tell us about any water getting in
- Try not to wet indoor joints just before the visit
- Tell us about any previous sealing or DIY attempts
Getting a quote
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we will talk you through the work and give you a clear quote.
Advice
What happens if it’s left?
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic is the like-for-like choice and that can be important for listed homes. Damp from a failed joint spreads quietly in older London brickwork and timber, and once it shows in Longlands, the repair is bigger than a sealant job.
Doing several joints on one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll give you a clear price for the lot.
Why us?
- ARBOMaster approved applicator
- Over 20 years’ experience
- We never seal over old sealant
- 180+ five-star Google reviews
Take a look at how sealant jobs are priced or what customers say.
Windows and doors in Longlands
With historic houses such as Eltham Palace (about 2 miles north-west) nearby, there’s older building stock in the area around Longlands 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 is traditional sand mastic. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Rented homes near New Eltham station change hands often, and any sash windows need sound mastic to keep draughts and rain out. If you look after a building such as Longlands Primary School, its window and door frames need their mastic kept sound, just like a home’s.
Longlands is about 1 mile west of Sidcup, in Greater London. If you need sand mastic in Longlands, please call 0345 464 0079 or email us for a quick quote. We are based in Crawley and cover Greater London. Longlands is one of 764 places in Greater London where we work for sand mastic. London is on our list too, about 9 miles from Longlands.
We cover every part of the DA15, DA14 and SE9 postcode area for sand mastic and the streets around it. You’ll find streets such as Main Road, Alder Road and Sidcup Road, and we cover them all. Longlands sits on or near the A211, which makes travel easy. If you are just outside Longlands, we cover Foxbury (1 mile south), New Eltham (1 mile north-west), Chislehurst (1 mile south-west), Coldharbour (1 mile west) and Blackfen (1 mile north). We also work in nearby towns such as London (9 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (13 miles west), St Pancras (11 miles north-west) and Shoreditch (10 miles north-west).
Local landmarks in Longlands
Typical jobs here are in homes near Waring Park, Chislehurst School for Girls and Ye Olde Black Horse Inn, among other places. The closest station to Longlands is New Eltham station, about 0.8 miles north-west of the centre. Nearby you’ll also find Queen Mary's Hospital (1 mile south-east) and Greenwich Castle (5 miles north-west). Open spaces near Longlands include Summer Hill and The Tarn.
Different surfaces, different methods
Period and listed homes
Materials matter on listed and conservation-area homes. Like-for-like sand mastic is generally favoured.
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
Landlord and commercial work in Longlands
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
Letting agents often deal with us directly. Tell us the address, the job and how access works.
Towns and villages near Longlands
Also in Longlands
Common problems we fix in Longlands
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint, which is a good time to renew it.
These are the problems we’re asked about most:
- Cracked mastic round a front door frame
- Cement or filler used on old window joints that has cracked
- Mastic dropping out of the joint
- Weathered mastic on the most exposed windows
For an older house near a landmark such as Christ Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What to look for in a quote
- What preparation is included
- Who does the work, and how experienced they are
- What happens if they find a problem under the old sealant
- What the cure time is
DIY versus a professional finish
If you’ve already had a go yourself, that is fine. We cut it out and start again, so tell us about it when you ask for a quote.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
What sealant work can’t fix
We will not take on work that won’t last, so these are the limits:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sashes that need overhauling
- Whether work needs listed building consent
Not sure which it is? You can phone 0345 464 0079 or email us and we will tell you honestly before you book.
Where we work in Longlands
- Tenement windows
- Brick reveals
- Sash and case windows
- Timber door frames
- Period & listed homes
- Stone surrounds