Greater London · England
Sand Mastic in Little Portugal
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in Little Portugal. Fully insured, ARBOMaster approved and guaranteed for a year.
- Patchy fillers round a sash window
- Draughts and rain around sash boxes
- Gaps between timber frames and stone or brick
Sand mastic for homes and businesses in Little Portugal
A silicone bead around a sash window can look out of place and doesn’t suit the building. Sand mastic gives a finish that matches the age of the house and we can swap the silicone for it. We work on sash and case windows, period & listed homes and tenement windows, and people most often call us about patchy fillers round a sash window and gaps where the frame meets the masonry.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Little Portugal (SW9, SW8, SW1P)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- A clear price before we start
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How to look after the new joints
Joint life depends on how it’s used and looked after. We suggest:
- Go gently near the mastic when preparing windows
- Ask a joiner to look at soft timber first
- Sort the mastic before the decorators arrive
- Ask the planning authority about consent for listed or conservation-area homes
Check the mastic when you check the paintwork. Small cracks are easier to deal with early.
Good mastic helps keep the frame dry. Once it fails, water can sit against the timber, which can lead to rot.
What sand mastic looks like in Little Portugal
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. Historic houses like Buckingham Palace (about 2 miles north-west) are a reminder that the area around Little Portugal has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
Schools such as Platanos College are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as St Stephen's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Little Portugal is about 1 mile north of Stockwell, in Greater London. Jobs in Little Portugal get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. 764 places in Greater London are on our list, from the larger towns to small villages.
We cover every part of the SW9, SW8 and SW1P postcode area for sand mastic and the streets around it. You will find streets such as Kay Road, Lett Road and Rita Road, all of which we cover. Little Portugal sits on or near the A203. We also cover the places around Little Portugal: South Lambeth (1 mile north), North Brixton (1 mile east), Stockwell (1 mile south), Kennington (1 mile north) and Oval (1 mile north). Larger places within reach include City of Westminster (3 miles north-west), Marylebone (3 miles north), Kensington (4 miles north-west), St Pancras (4 miles north), Shoreditch (4 miles north-east) and Walthamstow (9 miles north-east).
What’s near Little Portugal
We work in homes and buildings around Allen Edwards Primary School, Larkhall Park and The Canton Arms, among other places. You’ll also find Durand Academy (within half a mile east) and Lambeth Palace Library (1.6 miles north). The closest station to Little Portugal is Wandsworth Road station, roughly 0.7 miles south-west. Well-known places in the area include Type Museum (under half a mile east) and The Gordon Hospital (1.4 miles north-west). For a walk, there’s Knight's Hill and Battersea Park Lake.
Work for landlords, hotels and businesses
Hotels need rooms back in use, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.
When something else is needed
Sealant isn’t the answer to every problem, and we will tell you before work begins. Sealant won’t put right:
- Damaged stone surrounds
- Decisions on consent for listed homes
- Sashes that need overhauling
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly before booking.
Joints and surfaces we work on
- Tenement windows
- Stone surrounds
- Brick reveals
- Sash and case windows
- Period & listed homes
- Timber door frames
What happens if it’s left?
New mastic over crumbling mastic won’t hold. Raking out and preparing the joint gives it a sound base so the new mastic stays put. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble for homes in Little Portugal.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why us?
- Old sealant always removed completely
- Neat joints and a tidy finish
- Arbo and Everbuild products
- A 12-month guarantee on all work
Read what affects the cost or our reviews.
DIY versus a professional finish
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
How the visit works
There’s no need to move everything out, only the area right around the joints. Everything nearby is protected, and the work takes anything from a few hours to a full day, depending on how many windows in most cases. In Little Portugal, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Let us know about earlier repairs to the joints
- Tell us about access, such as stairs, a lift or high-level joints
Get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved.
Advice
Little Portugal: your questions answered
Is Little Portugal in your area for sand mastic?
Yes, Little Portugal is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or email us and tell us what needs doing.
Is parking a problem for a job in Little Portugal?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Do you offer different sealant colours?
Yes. White, clear and grey are common, and other colours are available for many products, and we agree the colour with you before we start.
Can you work on commercial sites?
Yes. Commercial and hotel work is a large part of what we do, as well as homes. Working times can be discussed when we quote.
Are you insured?
Yes. Full insurance covers our work.
Where do you work from?
Our base is Crawley. We work across South East England, London and Scotland.
Can old silicone round a sash window be swapped for sand mastic?
Yes, it’s a common request. All the old silicone is removed first so the mastic can sit properly.
How long will you be here?
That depends on how much there is to do, but most jobs take anything from a few hours to a full day, depending on how many windows. We’ll give you a better idea when we quote.
When to call us in Little Portugal
Timber frames move with the seasons. The movement cracks the mastic over time.
Keep an eye out for these signs:
- Draughts and rain around sash boxes
- Mastic worn away on windows facing the weather
- Patchy fillers round a sash window
- Mastic dropping out of the joint
Rented homes near Wandsworth Road station change hands often, and any sash windows need sound mastic to keep draughts and rain out.
Comparing quotes
- Who turns up on the day
- Is the old sealant removed completely?
- What insurance they hold
- Which sealant they’ll use, and why