Greater London · England
City of Westminster Sand Mastic
Sand mastic in City of Westminster from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Draughty sash windows at the surround
- Modern sealant on a period surround
- Mastic worn away on windows facing the weather
Sand mastic for homes and businesses in City of Westminster
For a listed home or one in a conservation area, ask your local planning authority whether consent is needed for work to windows. Sand mastic is often favoured as a like-for-like material. We work on period & listed homes, sash and case windows and stone surrounds, and the jobs we see most are window mastic to renew ahead of painting and draughts and rain around sash boxes.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, letting in draughts and water.
We stand behind the work with a 12-month guarantee, so you are not left on your own once the job is done.
- Where
- City of Westminster (W2, NW8, W9, SW1V)
- Wider area
- Greater London
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What we cannot put right
Some problems need a builder, plumber or other trade rather than us:
- Cracked or broken glass
- Damaged stone surrounds
- Sash cords, weights and draught-proofing of the sashes
If you’re not sure, just phone 0345 464 0079 or send us an email and we’ll give you a straight answer before you book.
Joints and surfaces we work on
- Brick reveals
- Tenement windows
- Timber door frames
- Sash and case windows
- Period & listed homes
- Stone surrounds
Questions from City of Westminster
Is parking an issue for sand mastic in City of Westminster?
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.
Can you help a landlord with a rental near Bond Street station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Where are you based?
We’re a Crawley-based firm. Our area covers South East England, London and Scotland.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
How long does the job take?
A typical job takes a few hours for a single window, longer for several, including preparation and clearing up. We’ll confirm how long when we quote.
Do you guarantee sand mastic work?
Our 12-month guarantee applies on every job.
Are you insured?
Yes, we are fully insured for every job we do.
Will the old sealant be removed?
Yes, always, and completely. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
What affects the quote in City of Westminster
We quote each job individually. This is what makes a difference:
- How easy the joints are to reach
- The number and length of the joints
- Any working-time requirements on site
- Whether old sealant or filler has to be cut out
A failed joint rarely gets cheaper to fix by waiting. If you’re not sure whether it needs doing, call 0345 464 0079 or email us and we will give you an honest view and a quote.
What we need to know
Photos by email are helpful but not essential. Try to tell us:
- The type of property
- How we’d reach the joints
- The address or postcode of the job
- How many joints, rooms or windows are involved
Want a quote for sand mastic? Please phone 0345 464 0079 or send us an email with a few details. We will explain what we’d do and send you a clear quote before we start.
Work for landlords, hotels and businesses
Hotels need rooms back in use, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
We also work for property managers and facilities teams in City of Westminster and across Greater London. We can quote a run of properties together, and we’re fully insured for the work.
What sand mastic looks like in City of Westminster
With historic houses such as Handel Hendrix House (about 0.3 miles east) nearby, there’s older building stock in the area around City of Westminster as well as newer homes. In older buildings, 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 check that before booking.
If you look after a building such as St Vincent's Catholic Primary School, larger buildings have plenty of frames, and the mastic around each one ages. City of Westminster is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
City of Westminster is about 3 miles west of London, in Greater London. Our applicators cover sand mastic for householders, landlords and businesses in City of Westminster and nearby. City of Westminster is one of 764 places in Greater London we cover.
Every address in W2, NW8, W9 and SW1V is covered for sand mastic, from the main roads to the quietest streets. That includes homes and businesses on Portman Square, Grosvenor Square and Cavendish Square and the roads around them. City of Westminster sits on or near the A4 and A5. Close by, we work in Marylebone (1 mile north-east), Mayfair (1 mile south-east), Tyburn (1 mile west), Burlington Estate (1 mile south-east) and Connaught Village (1 mile west). Within a short drive, we also cover London (3 miles south-east), Shoreditch (3 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles north-east), Whitechapel (4 miles east) and Hampstead (3 miles north-west). As one of the bigger places in Greater London, City of Westminster has homes, rented property and businesses of every kind.
Near you in City of Westminster
We work in homes and buildings around LITE Regal International School, Royal Society of Medicine Library and Devonshire Arms, among other places. You will also find The St Marylebone CofE School (0.5 miles north) and Hyde Park (0.6 miles south-west). City of Westminster has its own railway station: Bond Street station. Other landmarks nearby include Dunhill Museum & Archive (within half a mile north) and Kingly Court (0.6 miles east). Green spaces nearby include Serpentine and Primrose Hill.
Also near City of Westminster
Other services in City of Westminster
What we are called out for in City of Westminster
Shallow joints are a common cause. Mastic that is too thin cracks and drops out so we make sure the new mastic is the right thickness.
Look out for any of the following:
- Crumbling sand mastic round a window
- Cement or filler used on old window joints that has cracked
- Failed mastic on an exposed elevation
- Draughts and rain around sash boxes
Rented homes near Bond Street station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
What to look for in a quote
- When the joint can take water or movement
- Is the old sealant removed completely?
- Whether the sealant suits the joint
- The length of the guarantee
The process
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for a single window, longer for several, and the area is left clean. In a London area like City of Westminster, the main things to plan are parking and access: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- First, we look at the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- Keep pets and children clear of the area while we work
- Move anything stored near the joints
How to get a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll explain how we’d tackle it. When it suits you, call 0345 464 0079 or send us an email.
Advice
Why it’s worth doing now in City of Westminster
Draughts round a sash window aren’t always the sashes. Gaps between the frame and the wall can be just as bad and new mastic seals them. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in City of Westminster, the repair is bigger than a sealant job.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, along with when we can work on site. Call for a quick quote and we’ll explain what it covers.
Why book with us
- Any old sealant cut out fully, not covered over
- Over 20 years’ experience
- Fully insured
- Approved under the ARBOMaster scheme
Read our cost guide and what customers say.
DIY sealant or a professional job?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.