Greater London · England
Sand mastic for sash & case windows in Falconwood, Greater London
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Falconwood, backed by a one-year guarantee. Call for a quick quote.
- A silicone bead on a sash window that spoils the look
- Mastic dropping out of the joint
- Mastic worn away on windows facing the weather
Frames and glazing around Falconwood
Historic houses like Danson House (about 1 mile east) are a reminder that the area around Falconwood 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. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
In the older streets around Bishop Ridley Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Schools such as Bishop Ridley Church of England VA Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Welling station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Falconwood is about 2 miles north-east of Eltham, in Greater London. From the centre of Falconwood to the outskirts, sand mastic is available for homes and businesses alike, from flats and houses to offices and hotels. We cover 764 towns and villages across Greater London. You can also see our page for London, about 9 miles away.
Every address in DA16, DA15 and SE9 is covered for sand mastic, from the main roads to the quietest streets. If you need sand mastic at a property on Hook Lane, Gordon Road and Kent Avenue or anywhere close by, we can help. We also cover Blackfen (1 mile south), East Wickham (1 mile north), Avery Hill (1 mile south-west), Shooter's Hill (1 mile north-west) and New Eltham (2 miles south-west). Within a short drive, we also cover London (9 miles west), City of Westminster (11 miles west), Marylebone (11 miles west), Kensington (13 miles west), St Pancras (10 miles north-west) and Shoreditch (9 miles north-west).
Near you in Falconwood
Locally, jobs take us to homes and businesses close to The Plough and Harrow pub, Shoulder of Mutton Green and Harris Academy Falconwood, among other places. Falconwood’s nearest station is Welling station, about 0.5 miles north-east. Nearby you’ll also find Broadway Shopping Centre (2.2 miles east) and Memorial Hospital (1.4 miles north-west). The countryside around Falconwood includes The Tarn and Summer Hill.
Sand mastic for homes and businesses in Falconwood
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. Renewing it closes the gap so the surround looks right again. We’re often asked to deal with gaps between timber frames and stone or brick and draughty sash windows at the surround, across sash and case windows, timber door frames and tenement windows.
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, in Falconwood as anywhere.
We stand behind the work with a one-year guarantee, so you are not left on your own once the job is done.
- Location
- Falconwood (DA16, DA15, SE9)
- Region
- Greater London
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We also work for property managers and facilities teams. Several sites can be quoted together.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
DIY sealant or a professional job?
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Towns and villages near Falconwood
More services for Falconwood
Questions from Falconwood
Can you do sand mastic in Falconwood?
Yes, Falconwood is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and let us know what needs doing, and we will give you a clear quote.
Can parking be tricky for a visit in Falconwood?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Does someone need to be in?
It depends on the job. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.
Will there be a smell?
Possibly a little. Any smell clears as the sealant cures.
Is it possible to paint over sand mastic?
It’s traditionally left unpainted, which is what traditional guidance recommends. Ask us before decorating.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint.
What does sand mastic cost?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or send us an email and tell us what needs doing and where.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It’s made with sand and a linseed-oil-based binder.
What affects the quote in Falconwood
Every job gets its own quote. These are the things that affect it:
- Whether old sealant or filler has to be cut out
- The type of sealant required
- How many areas need sealing
- Working hours on commercial sites
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Where the property is
- What’s wrong with the joints now
- Any previous sealing or DIY work
- Roughly how big the job is
Every job is quoted individually, so the first step is telling us about yours. Simply phone 0345 464 0079 or drop us an email and describe the job.
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Inspect the joints round the windows every year or so
- Get any rot dealt with first
- Avoid heavy scraping on the mastic joint
- Plan mastic work ahead of painting
Avoid painting over the new mastic, as traditional guidance advises. If you’re redecorating, ask us first.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.
Why act early in Falconwood
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in and new mastic seals them. In a flat in Falconwood, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Doing several joints on one visit is generally more efficient than separate visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Why us?
- Sanitary silicone with an anti-fungal additive in wet areas
- An ARBOMaster approved applicator
- Over 20 years’ experience
- Domestic, commercial and hotel work
See our cost guide or what customers say.
When something else is needed
We’d rather tell you now than do work that will not last, so here’s what sealant can’t put right:
- Putty and glazing repairs
- Whether work needs listed building consent
- Sashes that need overhauling
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly.
Joints and surfaces we work on
- Timber door frames
- Sash and case windows
- Tenement windows
- Brick reveals
- Stone surrounds
- Period & listed homes
How the visit works
Every visit runs the same way: we check the joints, mask and protect the surrounding surfaces, do the work and tidy away. It usually takes a few hours for a single window, longer for several. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- 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
- Let us know about stairs, lifts or work at height
- Mention if the joints have been sealed before
- Mention any leaks or damp you’ve noticed
Ask for a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. A few pictures by email make the job easier to understand, and we will come back to you with a quote.