Greater London · England
Mayfair Sand Mastic
Window and door surrounds in Mayfair need attention? We cut out the old, prepare the joints and apply the right sealant.
- Draughty sash windows at the surround
- A silicone bead on a sash window that spoils the look
- Open joints round the window box
How we handle sand mastic in Mayfair
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. If you have cement or filler used on old window joints that has cracked and mastic worn away on windows facing the weather, we can help, on stone surrounds, period & listed homes and sash and case windows alike.
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 Mayfair is something to talk through when you book.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we will put it right.
- Location
- Mayfair (W1K, W1F, W1U)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Signs you need sand mastic in Mayfair
Paint, silicone or cement used over old mastic causes problems. They don’t suit the joint, and they normally need raking out.
Signs it’s time to call us include:
- Mastic worn away on windows facing the weather
- Modern sealant on a period surround
- Window mastic to renew ahead of painting
- Old sand mastic that has cracked, crumbled or fallen out
For site and facilities teams at buildings such as LITE Regal International School, larger buildings have plenty of frames, and the mastic around each one ages.
What to look for in a quote
- How much experience the applicator has
- What guarantee comes with the work
- What insurance they hold
- What happens if the job turns out different
Quotes for sand mastic in Mayfair
The quote reflects the job in front of us. We take into account:
- The number of rooms or windows
- Working hours on commercial sites
- How much old sealant there is and how hard it is to remove
- Which sealant suits the joint
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you’re unsure, 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
There’s no need for technical detail. Just tell us:
- How many joints, rooms or windows are involved
- Where the job is, and your postcode
- Any previous sealing or DIY work
- What the problem is, such as mould, gaps, leaks or cracking
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we’ll talk you through the work and give you a clear price.
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Do not run silicone over sand mastic
- Leave the new mastic unpainted
- Avoid heavy scraping on the mastic joint
- Ask a joiner to look at soft timber first
When preparing windows for paint, take care around the mastic. Hard scraping can loosen it.
Good mastic helps keep the frame dry. Once it fails, water can sit against the timber, which can lead to rot.
Work for landlords, hotels and businesses
If you manage several properties in or around Mayfair, several properties can go on one quote. Just tell us the addresses and what each one needs.
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
Why deal with it now?
Before painting the windows, it pays to renew the mastic. Painting over failed mastic doesn’t seal it, and the new mastic is traditionally left unpainted. 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.
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs, plus any working-time requirements on site. Call for a quick quote and we will go through it with you.
Why choose Mr Mastic in Mayfair
- We leave the area clean and tidy
- Approved under the ARBOMaster scheme
- Arbo and Everbuild products
- We’re fully insured
Read what affects the cost or customer reviews.
Towns and villages near Mayfair
More services for Mayfair
FAQs for Mayfair
I let a flat near Bond Street station. Can you help?
Yes, we work for landlords and agents. You can call 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Can you do sand mastic in Mayfair?
Yes. We work across London and the South East, and Mayfair is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Is it OK to seal over old sealant?
No, because it fails. The old sealant always comes out first, so the new joint bonds to clean surfaces.
Is it possible to take out silicone and use sand mastic instead?
Often, yes. With the silicone removed and the joint cleaned we point it with sand mastic.
Is consent needed for window work on a listed home?
Your local planning authority is the one to ask. They decide whether consent is needed.
What sealant do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
What does sand mastic cost?
It depends on the job, so we quote each one individually. To get one, call 0345 464 0079 or email us and let us know what needs doing and where.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. Working times can be discussed when we quote.
Windows and doors in Mayfair
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. With historic houses such as Handel Hendrix House (about 0.2 miles north) nearby, there’s older building stock in the area around Mayfair as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
As a London address, Mayfair can be tricky for parking: let us know about parking bays, permits or a driveway. In the older streets around Grosvenor Chapel, the joint between an old wall and a newer frame is usually the first place rain gets in.
Mayfair is about 1 mile south-east of City of Westminster, in Greater London. We provide sand mastic to homes and businesses in Mayfair and nearby. Our area takes in 764 places across Greater London, large and small.
We work across W1K, W1F and W1U for sand mastic. If you need sand mastic at a property on Park Lane, Bruton Lane and Market Mews or a nearby road, we can help. Mayfair is on the A4201 and A4202, which makes it straightforward to reach with everything needed for sand mastic. Other places close to Mayfair include Burlington Estate (1 mile east), City of Westminster (1 mile north-west), Marylebone (1 mile north), St James's (1 mile east) and Chinatown (1 mile east). We also work in nearby towns such as Shoreditch (3 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles north-east), Whitechapel (3 miles east), Hampstead (3 miles north-west) and Ruislip (12 miles west).
Local landmarks in Mayfair
Locally, jobs take us to homes and businesses close to Royal College of Nursing Library & Museum, Coach and Horses pub and St George's Church of England Primary School. Also close by are Green Park (0.5 miles south) and The St Marylebone CofE School (0.8 miles north). Mayfair has its own railway station: Bond Street station. Nearby you’ll also find Montfichet's Tower (2 miles east) and London Eye Hospital (0.5 miles north). Green spaces nearby include Ludgate Hill and St. James's Park Lake.
When it is not the sealant
It helps to know what we cannot do too:
- Planning or listed building consent (your local planning authority decides)
- Decayed frames that need repair
- Putty and glazing repairs
If in doubt, call 0345 464 0079 or email us and we will say what we think before booking.
What we seal
- Tenement windows
- Period & listed homes
- Timber door frames
- Sash and case windows
- Stone surrounds
- Brick reveals
How it works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes anything from a few hours to a full day, depending on how many windows and we leave things clean and tidy. In Mayfair, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by checking each surround and agreeing the joints to renew.
- Old, loose mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Preparing for the visit
- For indoor joints, keep the area dry beforehand if you can
- Let us know if you’ve seen damp or leaks
- Plan for the work area to be out of bounds to pets and children
Getting a quote
Asking for a quote is easy: tell us what needs doing and where. Photos by email help us understand the job, and we will take it from there.