Greater London · England
Sand Mastic in Forestdale
Problem with your window and door surrounds in Forestdale? We cut out the old, prepare the joints and apply the right sealant.
- Cracked mastic round a front door frame
- Old cement repairs round a window that have failed
- A silicone bead on a sash window that spoils the look
Sand mastic for homes and businesses in Forestdale
Fresh sand mastic forms a skin quite soon, but it takes longer to harden fully. Traditionally, sand mastic is left unpainted, so ask us before you decorate. Common call-outs are for silicone on a period window that looks wrong and mastic round period door frames that has failed, across timber door frames, period & listed homes and stone surrounds.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
There’s a 12-month guarantee on every job, whatever its size.
- Location
- Forestdale (CR0, CR2)
- Wider area
- Greater London
- Cover
- A year, on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What sand mastic looks like in Forestdale
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you let a flat or house near Sanderstead station, older sash windows in a rental need their mastic kept sound to keep the weather out. As a London address, Forestdale can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. If you live in an older home near St Francis, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Forestdale is about 3 miles south-east of Croydon, in Greater London. Jobs in Forestdale get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Forestdale is one of 764 towns and villages in Greater London where we work for sand mastic. We also work in London, around 11 miles away.
Work in CR0 and CR2 works the same way as everywhere else we cover. You’ll find streets such as Courtwood Lane, Goldfinch Road and Bardolph Avenue. Neighbouring places we cover for sand mastic include Selsdon (1 mile west), New Addington (1 mile east), Addington (1 mile north), Farleigh (1 mile south) and Fickleshole (2 miles south-east). Within a short drive, we also cover London (11 miles north), City of Westminster (13 miles north-west), Marylebone (13 miles north), Kensington (13 miles north-west), St Pancras (13 miles north) and Shoreditch (13 miles north).
Landmarks near Forestdale
In Forestdale, that means homes and buildings near John Ruskin College and Addington Park, among other places. The closest station to Forestdale is Sanderstead station, about 2.4 miles west of the centre. Nearby you’ll also find Warlingham Park Hospital (1.9 miles south) and Croydon Airport Visitor Centre (3.5 miles west). Not far away are Nore Hill and Hutchinson's Bank.
What affects the quote in Forestdale
The price is agreed before any work begins. It takes into account:
- Any working-time requirements on site
- How many areas need sealing
- How much old sealant there is and how hard it is to remove
- Any mould that needs treating
What it costs depends on the amount of work, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before work begins, so you know where you stand.
Helping us quote
When you call or email, it’s useful to know:
- What’s wrong with the joints now
- Access, such as stairs, a lift or height
- The type of property
- The address or postcode of the job
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. A few photos by email make the job easier to understand, and we will take it from there.
For landlords and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Take care around the mastic when scraping paint
- Don’t run silicone over sand mastic
- Plan mastic work ahead of painting
- Keep sills and gutters clear so water drains away
Avoid painting over the new mastic, as traditional guidance advises. Ask us before any decorating around it.
Sound mastic protects the frame. Once it fails, water can sit against the timber, which can lead to rot.
What we do, step by step
There is not much for you to do on the day. Point us to the joints and we will get on with it. The job generally takes a few hours for a single window, longer for several. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Forestdale. 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.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Mention any tricky access
- Mention if the joints have been sealed before
Ask for a quote
Need a quote? Please call 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
Can I do it myself?
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.
If you’ve already had a go yourself, that is fine. We cut it out and start again, so just mention it when you contact us.
Why act early in Forestdale
New mastic over crumbling mastic won’t hold. Raking out and preparing the joint gives it a sound base so the new work lasts. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Forestdale, the repair is bigger than a sealant job.
The cost reflects the work involved, not guesswork. That is why we ask about the job first and send you a clear quote before work begins.
Why us?
- An ARBOMaster approved applicator
- 20+ years of sealant experience
- Old sealant always removed completely
- Full insurance on every job
Read how sealant jobs are priced and our reviews.
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.
Brick reveals
Loose mastic comes out and deep gaps are packed before the new mastic goes in.
Your questions about sand mastic in Forestdale
Can you help a landlord with a rental near Sanderstead station?
Yes, we work for landlords and letting agents. Just call 0345 464 0079 or send us an email and tell us about the property, and we’ll send you a clear quote.
Is parking an issue for sand mastic in Forestdale?
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.
Is there any odour?
Some sealants have a smell while they cure, but it fades. Ventilation helps.
Can I do it myself?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you do not need to watch us work.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Will you leave a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
What do you need from me for a quote?
A short description and the location, plus pictures if you have them. We will ask anything else we need to know.