Greater London · England
Farthing Street Sand Mastic
Professional sand mastic in and around Farthing Street, with every bit of old sealant taken out first and a 12-month guarantee.
- Open joints round the window box
- Silicone on a period window that looks wrong
- Mastic dropping out of the joint
Signs you need sand mastic in Farthing Street
Decorating can disturb tired mastic. Many people find it crumbling when they prepare the windows, which is a good time to renew it.
It’s worth asking for a quote if you see:
- Old sand mastic that has cracked, crumbled or fallen out
- Tired mastic found when preparing windows for paint
- Open joints round the window box
- A silicone bead on a sash window that spoils the look
If you look after a building such as Downe Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Before you book anyone
- Which sealant they’ll use, and why
- Whether they’re fully insured
- What preparation is included
- Is VAT in the price?
How we handle sand mastic in Farthing Street
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditionally, sand mastic is left unpainted and we’ll advise if you’re redecorating. Typical jobs include weathered mastic on the most exposed windows and open joints round the window box, on stone surrounds, timber door frames and brick reveals.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first, and access in Farthing Street is something to talk through when you book.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Farthing Street (BR6)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
DIY sealant or a professional job?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
What we do, step by step
On the day, we start by going over the job with you. Surfaces next to the work are protected before any work begins. Most jobs take a few hours for a single window, longer for several. For a job in Farthing Street, parking and access are the things to plan: let us know about parking, the floor we’ll 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.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Mention any sign-in or site rules at work premises
- Keep pets and children clear of the area while we work
- Clear the area around the work
Get a quote
Need a quote? Please ring 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.
Advice
Leave it or put it right?
A silicone bead can be quicker, but it can look wrong on a period surround. Sand mastic suits the building and blends with the stone or brick. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler.
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why Farthing Street clients choose us
- Old sealant always removed completely
- An ARBOMaster approved applicator
- Anti-fungal silicone where joints get wet
- Domestic, commercial and hotel work
Read how sealant jobs are priced or our reviews.
What the job involves on each surface
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We can do one window or several.
Brick reveals
Brick reveals round timber windows are often pointed with sand mastic. It suits older brickwork.
Farthing Street: your questions answered
Do you work for landlords with property near Orpington station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can be quoted together. You can phone 0345 464 0079 or send us an email with the details for a clear quote.
Can parking be tricky for a visit in Farthing Street?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Can new sealant go over the old?
No, it will not last. It may look fine at first, but the new layer lifts away from the old one. The old sealant has to come out completely.
Will you leave a mess?
Tidy work is part of the job. Nearby surfaces are protected.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What’s sand mastic made of?
Sand plus a binder based on linseed oil. It’s built up in the joint by hand and shaped to suit the surround.
Where is Mr Mastic based?
We’re a Crawley-based firm. We work across South East England, London and Scotland.
How long does the job take?
A typical job takes anything from a few hours to a full day, depending on how many windows. Your quote will say how long we expect yours to take.
Nearby places to Farthing Street
More services for Farthing Street
Farthing Street homes and the weather
Historic houses like Down House (about 1 mile south) are a reminder that the area around Farthing Street has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. 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 Orpington station, any sash windows need sound mastic to keep draughts and rain out. Homes close to St Mary's Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Farthing Street is about 4 miles south-west of Orpington, in Greater London. Whether you’re in the middle of Farthing Street or further out, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Across Greater London, we cover 764 places, Farthing Street among them. London is on our list too, around 12 miles away.
Postcode districts we cover here for sand mastic: BR6. If you need sand mastic at a property on Farthing Street, New Road Hill and Orange Court Lane or a nearby road, our applicators can take on the job. If you are just outside Farthing Street, we cover Downe (1 mile south-east), Leaves Green (1 mile south-west), Hazelwood (1 mile south-east), Keston (1 mile north-west) and Farnborough (1 mile north-east). Larger places within reach include London (12 miles north-west), City of Westminster (15 miles north-west), Marylebone (15 miles north-west), Kensington (15 miles north-west), St Pancras (14 miles north-west) and Shoreditch (14 miles north-west).
Landmarks near Farthing Street
We work in homes and buildings around Darrick Wood School, South Park and The Queens Head pub, among other places. Farthing Street’s nearest station is Orpington station, about 2.6 miles north-east. Nearby you will also find Princess Royal University Hospital (1.4 miles north) and Crofton Roman Villa (2.5 miles north-east). For a walk, there’s Betsom's Hill and West Kent Golf Course nature reserve.
Keeping the joints in good condition
Good habits help new joints last longer. Our tips:
- Get any rot dealt with first
- Look over the window mastic once a year
- Keep modern sealant off the mastic
- Clear gutters so water does not pour onto the windows
Keep paint scrapers and sanders off the mastic when redecorating. It can be damaged by heavy scraping.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall so early renewal protects both.
When something else is needed
Sealant isn’t the answer to every problem, and we will tell you before we start. Sealant will not put right:
- Putty and glazing repairs
- Crumbling stone or brickwork round the window
- Decayed frames that need repair
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
Where we work in Farthing Street
- Brick reveals
- Sash and case windows
- Period & listed homes
- Tenement windows
- Timber door frames
- Stone surrounds