Greater London · England
Sand mastic for sash & case windows in Dartmouth Park, Greater London
Sand mastic across Dartmouth Park and nearby, with old sealant always removed completely.
- Mastic round period door frames that has failed
- Wind and rain getting in round a sash window
- Mastic worn away on windows facing the weather
Sand mastic for homes and businesses in Dartmouth Park
Traditional burnt sand mastic that sits naturally against stone and brick. It’s a good fit for period properties where a modern sealant bead would stand out. We work on stone surrounds, sash and case windows and brick reveals, and people most often call us about a silicone bead on a sash window that spoils the look and wind and rain getting in round a sash window.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Where
- Dartmouth Park (NW5, N19, N7)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before we start
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Can I do it myself?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
A careful DIYer can reseal a simple joint, 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.
Places near Dartmouth Park
What else we do in Dartmouth Park
Questions from Dartmouth Park
Do you cover Dartmouth Park for sand mastic?
Yes. We work across London and the South East, and Dartmouth Park is part of that. You can ring 0345 464 0079 or email us and tell us what needs doing, and we will give you a clear quote.
Can you help a landlord with a rental near Gospel Oak station?
Yes, rental work is part of what we do. Just call 0345 464 0079 or email us and tell us about the property, and we’ll give you a clear price.
Where are you based?
We’re a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Is it messy?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Is sand mastic better than silicone for my windows?
We will talk it through with you. Period homes often look best with sand mastic, and modern sealants suit newer frames.
Which products do you use?
Quality sealants from brands including Arbo and Everbuild, picked for each joint. We will tell you what we are using and why.
Are you insured?
Yes, we are fully insured for every job we do.
What do you need from me for a quote?
Just the basics: where it is, what you’ve noticed and how we reach it. Then call 0345 464 0079 or email us.
Surface by surface
Stone surrounds
We take care not to mark the stone while raking out the old mastic.
Timber door frames
Round a period front door, sand mastic gives the right look.
What sand mastic looks like in Dartmouth Park
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
For landlords with property near Gospel Oak station, cracked sand mastic around sash windows lets in the draughts tenants complain about. As a London address, Dartmouth Park can be tricky for parking: let us know about parking bays, permits or a driveway.
Dartmouth Park is about 2 miles east of Hampstead, in Greater London. Jobs in Dartmouth Park get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Dartmouth Park is one of 764 towns and villages in Greater London where we work for sand mastic.
Jobs for sand mastic in NW5, N19 and N7 works the same way as everywhere else we cover. You’ll find streets such as Hugo Road, Ward Road and Anson Road. Close by, we work in Lissenden Gardens (1 mile south-west), Tufnell Park (1 mile east), Gospel Oak (1 mile south-west), Upper Holloway (1 mile north-east) and Highgate (1 mile north). Within a short drive, we also cover London (5 miles south-east), City of Westminster (3 miles south), Marylebone (3 miles south), Kensington (5 miles south-west), St Pancras (3 miles south-east) and Shoreditch (4 miles south-east).
What’s near Dartmouth Park
Around Dartmouth Park, our work takes us to homes and buildings near The Dartmouth Arms, Whittington Park and Brookfield Primary School. Other local landmarks include Asanté Academy of Chinese Medicine (1.4 miles north) and Vaughan Williams Memorial Library (1.5 miles south). Dartmouth Park’s nearest station is Gospel Oak station, about 0.5 miles south-west. Well-known places in the area include O2 Centre (1.8 miles south-west) and Isokon Gallery (1 mile south-west). The countryside around Dartmouth Park includes Belsize Wood and Dartmouth Park Hill.
What happens on the day
We keep the work tidy and contained to the area we’re working on, so you can get on with your day. The job usually takes a few hours for a single window, longer for several, and we tell you how long to leave it before we go. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Dartmouth Park. A visitor permit or a nearby bay makes the visit run more smoothly.
- We look at the surrounds with you and agree the joints to renew.
- 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
- Keep pets and children clear of the area while we work
- Tell us about access, such as stairs, a lift or high-level joints
- For indoor joints, keep the area dry beforehand if you can
How to get a quote
For sand mastic in Dartmouth Park, call 0345 464 0079 or send us an email. Tell us what the problem is and where, and we will agree the price before any work begins.
Related advice
When to call us in Dartmouth Park
Sand mastic slowly weathers. It dries out, cracks and loses its grip from the frame or the masonry.
If you can see any of these, it’s time to have the joints looked at:
- Patchy fillers round a sash window
- Old sand mastic that has cracked, crumbled or fallen out
- Failed mastic on an exposed elevation
- Mastic round period door frames that has failed
Schools such as Acland Burghley School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
Before you book anyone
- How hidden problems are handled
- How the surfaces are prepared before sealing
- Who does the work, and how experienced they are
- The length of the guarantee
When something else is needed
It helps to know what we can’t do too:
- Whether work needs listed building consent
- Cracked or broken glass
- Damaged stone surrounds
If in doubt, call 0345 464 0079 or drop us an email and we’ll say what we think.
Joints and surfaces we work on
- Sash and case windows
- Tenement windows
- Brick reveals
- Timber door frames
- Period & listed homes
- Stone surrounds
How to look after the new joints
To keep the joints looking good and working properly:
- Clear gutters so water doesn’t pour onto the windows
- Go gently near the mastic when preparing windows
- Ask the planning authority about consent for listed or conservation-area homes
- Ask us before painting near the mastic
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at before trying a quick fix.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.
Leave it or put it right?
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in, and renewing the mastic closes them. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs, plus any working-time requirements on site. Ask us for a quote and we will go through it with you.
Why us?
- 12-month guarantee on every job
- Experience in homes, commercial sites and hotels
- We leave the area clean and tidy
- Full insurance on every job
Read what affects the cost and what customers say.