Greater London · England
Sand Mastic in Riddlesdown
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Riddlesdown, with a one-year guarantee on every job. Call for a quick quote.
- Cement or filler used on old window joints that has cracked
- Silicone on a period window that looks wrong
- Old sand mastic that has cracked, crumbled or fallen out
How we handle sand mastic in Riddlesdown
Across Riddlesdown, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand for a neat, traditional finish. Typical jobs include old sand mastic that has cracked, crumbled or fallen out and gaps between timber frames and stone or brick, across timber door frames, sash and case windows and tenement windows.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Location
- Riddlesdown (CR8, CR2)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Different surfaces, different methods
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
Sash and case windows
Sash windows are where we do most sand mastic work. We renew the mastic round each box.
What we are called out for in Riddlesdown
Timber frames move with the seasons. The movement cracks the mastic over time.
Signs it’s time to call us include:
- Patchy fillers round a sash window
- Weathered mastic on the most exposed windows
- Cracked mastic round a front door frame
- Wind and rain getting in round a sash window
Letting a property close to Riddlesdown station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about.
Questions to ask before you book
- How the surfaces are prepared before sealing
- What product goes in the joint
- What the quote includes, VAT included or not
- When the joint can take water or movement
Riddlesdown homes and the weather
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Addington Palace (about 3 miles north-east) are a reminder that the area around Riddlesdown 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.
Managing a site like Harris Primary Academy Kenley? Then the mastic around its windows and doors needs looking after like any other building’s. In the older streets around St Edmund's Church, the joint between an old wall and a newer frame is usually the first place rain gets in.
Riddlesdown is about 1 mile east of Purley, in Greater London. Riddlesdown gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. We cover 764 towns and villages across Greater London, from the larger towns to small villages. You can also see our page for London, roughly 12 miles from Riddlesdown.
Our applicators cover all of CR8 and CR2 for sand mastic. Sand mastic is available to properties on Hyde Road, Lower Road and Famet Avenue and the roads around them. Riddlesdown is on the A22, which makes it straightforward to reach with everything needed for sand mastic. If you’re just outside Riddlesdown, we cover Kenley (1 mile south), Sanderstead (1 mile north-east), South Croydon (2 miles north), Hamsey Green (2 miles south-east) and Whyteleafe (2 miles south). Within a short drive, we also cover London (12 miles north), City of Westminster (13 miles north), Marylebone (13 miles north), Kensington (13 miles north), St Pancras (14 miles north) and Shoreditch (13 miles north).
Near you in Riddlesdown
Locally, jobs take us to homes and businesses close to Riddlesdown Collegiate and Dollypers Hill. Riddlesdown has its own railway station: Riddlesdown station. A little further out are Croydon Airport Visitor Centre (2 miles north-west) and Purley War Memorial Hospital (1 mile north-west). Not far away are Duppas Hill and Foxley Wood.
Why act early in Riddlesdown
Replacing sash windows is a big decision for a period home, and in listed buildings it may need consent. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Riddlesdown, the repair is bigger than a sealant job.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all make a difference.
What you get with us
- 4.9 on Google from 180+ five-star reviews
- Sanitary silicone with an anti-fungal additive in wet areas
- Experience in homes, commercial sites and hotels
- Any old sealant cut out fully, not covered over
Read what affects the cost or our reviews.
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
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.
FAQs for Riddlesdown
I let a flat near Riddlesdown station. Can you help?
Yes, rental work is part of what we do. Just call 0345 464 0079 or send us an email and tell us about the property, and we will send you a clear quote.
Is Riddlesdown in your area for sand mastic?
Yes. We work across London and the South East, and Riddlesdown is part of that. You can call 0345 464 0079 or send us an email and let us know what needs doing.
What exactly is sand mastic?
A traditional pointing material made from sand and a linseed-oil-based binder, used between timber frames and stone or brick.
Are you ARBOMaster approved?
Yes. We are approved under the ARBOMaster scheme.
Is sand mastic better than silicone for my windows?
Sand mastic usually suits period timber windows best. Modern frames normally suit a flexible sealant, and we’ll explain why.
Will it make a mess?
We keep the work tidy. Nearby surfaces are protected, and we clear up when we are done.
Does someone need to be in?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Which products do you use?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we’ll explain our choice.
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Renew mastic before redecorating the windows
- Find out about consent before window work on a listed home
- Avoid heavy scraping on the mastic joint
- Have rotten timber repaired before new mastic goes in
Avoid painting over the new mastic, which is the traditional advice. Ask us before any decorating around it.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry, so renewing it early is worth it.
Also near Riddlesdown
Also in Riddlesdown
What affects the quote in Riddlesdown
Some jobs are bigger than they look, and some smaller. The main factors:
- Mould in or behind the old joints
- The number of rooms or windows
- The old material and how stubborn it is
- The number and length of the joints
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are not sure whether it needs doing, call 0345 464 0079 or email us and we’ll give you an honest view and a quote.
What to tell us for a quote
When you call or email, it’s useful to know:
- The address or postcode of the job
- What’s wrong with the joints now
- Any previous sealing or DIY work
- How we’d reach the joints
Asking for a quote is easy: let us know the job and the location and its rough size. Photos by email help us understand the job.
How the visit works
All our tools and materials come with us in the van, so you don’t need to buy or prepare anything. After a quick look at the joints together, the area is protected and the work begins. Most jobs take anything from a few hours to a full day, depending on how many windows. In Riddlesdown, 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.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
How to prepare
- Mention if the joints have been sealed before
- Keep pets and children clear of the area while we work
- Try not to wet indoor joints just before the visit
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.