Greater London · England
Sand mastic for sash & case windows in Upminster, Greater London
Window and door surrounds in Upminster need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Cracked mastic round a front door frame
- Failed mastic on an exposed elevation
- Gaps between timber frames and stone or brick
How we handle sand mastic in Upminster
Fresh sand mastic forms a skin quite soon, but it takes longer to harden fully. Traditional guidance is not to paint over it and we will advise if you are redecorating. We work on timber door frames, period & listed homes and stone surrounds, and people most often call us about silicone on a period window that looks wrong and failed mastic on an exposed elevation.
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.
We stand behind the work with a one-year guarantee.
- Place
- Upminster (RM14, RM11)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Looking after it afterwards
Good habits help new joints last longer. A few tips:
- Avoid patching sand mastic with silicone
- Check with your local planning authority if your home is listed
- Ask a joiner to look at soft timber first
- Make sure water runs off the sill
Check the mastic when you check the paintwork. Catching cracks early keeps repairs small.
Fine cracks show the mastic is starting to fail. It’s easier to renew it before it drops out.
Surface by surface
Period and listed homes
Sand mastic is the like-for-like choice for many period homes. On listed buildings, check with your planning authority first.
Sash and case windows
A sash window’s box frame sits in the masonry opening. Sand mastic seals the joint round it.
Landlords, agents and businesses in Upminster
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
Letting agents and landlords in Upminster can book us as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
What we do, step by step
We keep the work tidy and contained to the joints we are treating. 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. In a London area like Upminster, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- 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.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- Plan for the work area to be out of bounds to pets and children
- Try not to wet indoor joints just before the visit
How to get a quote
For a quote, call 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We will give you a clear quote before any work starts.
Related advice
Questions from Upminster
Is parking a problem for a job in Upminster?
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.
Do you cover Upminster for sand mastic?
Yes. We work across London and the South East, and Upminster is part of that. You can phone 0345 464 0079 or email us and tell us what needs doing, and we will give you a clear quote.
Do you have insurance?
Yes, we’re fully insured.
I rent my home. Can I book you?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Should I try DIY first?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
What’s sand mastic made of?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Do you guarantee sand mastic work?
Our 12-month guarantee applies to all our work.
Nearby places to Upminster
Other services in Upminster
DIY sealant or a professional job?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
When it is not the sealant
In fairness, there are a few things sealant won’t fix:
- Sash cords, weights and draught-proofing of the sashes
- Crumbling stone or brickwork round the window
- Whether work needs listed building consent
If you’re not sure, just ring 0345 464 0079 or send us an email and we’ll give you a straight answer.
What we seal
- Stone surrounds
- Period & listed homes
- Tenement windows
- Timber door frames
- Sash and case windows
- Brick reveals
Leave it or put it right?
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and blends with the stone or brick. In a flat in Upminster, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Homes and businesses are quoted the same way: 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 explain what it covers.
What you get with us
- 180+ five-star Google reviews
- 12-month guarantee on every job
- Anti-fungal silicone where joints get wet
- Old sealant always removed completely
Take a look at what affects the cost or customer reviews.
Frames and glazing around Upminster
Historic houses like Hare Hall (about 2.6 miles north-west) are a reminder that the area around Upminster has older buildings as well as new. 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. In a converted house or block, who looks after the windows depends on the lease, so check that before you book.
Managing a site like Upminster Junior School? Then the mastic around its windows and doors needs looking after like any other building’s. As a London address, Upminster can be tricky for parking: let us know about parking bays, permits or a driveway. In the older streets around Church of St Laurence, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Upminster is about 2 miles east of Hornchurch, in Greater London. Wherever you are in the RM14 postcode area, our applicators can take on sand mastic. Across Greater London, we cover 764 places, and Upminster is one of them. We also work in London, around 16 miles away.
Postcode districts we cover here for sand mastic: RM14 and RM11. We cover properties on Station Road, Latham Place and Deyncourt Gardens. We also cover Upminster Bridge (1 mile west), Cranham (1 mile east), Emerson Park (1 mile north-west), Hornchurch (2 miles west) and Puddle Dock (2 miles east). Within a short drive, we also cover Shoreditch (14 miles west), Walthamstow (12 miles west), Hoxton (15 miles west), Whitechapel (14 miles west), Orpington (14 miles south-west) and Highbury (15 miles west).
Local landmarks in Upminster
Around Upminster, our work takes us to homes and buildings near Eastbrook School, St. Andrew's Park and The Crumpled Horn pub and the streets around them. There’s a railway station in Upminster itself: Upminster station. Well-known places in the area include Upminster Tithe Barn Museum of Nostalgia (0.5 miles north) and The Mercury Mall (3.2 miles north-west). Open spaces near Upminster include Cranham Marsh.