Marylebone mastic sealing
Work needed on a mastic joint in Marylebone? We look at it, seal it with the right product and hand it over with a 12-month guarantee.
- Complaints coming in block by block
- Patchy repairs in mismatched sealant
- Brittle perimeter mastic across a building
Mastic sealing for Marylebone sites
Share the site address and what’s failing, and we’ll reply with a fixed quote or arrange a visit.
How we handle mastic sealing in Marylebone
Across Marylebone and the rest of Greater London, we work the same way: you send details, we return a fixed quote, the joints are resealed and the 12-month guarantee follows. Addresses, photographs of typical joints and a rough idea of quantities let us give a quick quote or we can visit. We work on communal entrances and stairwells, communal kitchens and washrooms and shopfronts below residential blocks, and the usual reasons a site gets in touch are damp patches beside frames and draughts at frames across a block. One point of contact handles commercial sealant work in Marylebone from the first photographs to the final walk-round, whether it’s one building or several.
London has a large stock of purpose-built blocks, mansion flats and converted buildings managed by agents and housing associations. Mastic around windows, doors and balconies tends to fail across a whole block at a similar time.
We stand behind the joints we seal: 12 months, guaranteed. It covers how we prepared and applied the sealant, and if something we did falls short, we return to it.
- Place
- Marylebone (W1U, W1T, W1K)
- Wider area
- Greater London
- Cover
- 12 months on every job
- Price
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Last updated
- 3 November 2026
Our process
When we get to site, we sign in, go through any site induction and check how permits are handled. Floors, finishes and fittings next to the joints are covered before anything is cut or cleaned, with the work itself normally taking anything from a day to a few weeks, depending on the number of buildings and joints. The ULEZ covers the whole of Greater London, and parking near a job is rarely simple. If there’s a loading bay, a car park or a permit we can use, tell us when you send details.
- First comes a look at the joints and, for older buildings, the asbestos records.
- A fixed quote covers the joints, products and order of work.
- Failed mastic is removed completely.
- The joints are prepared and resealed with the right product.
- Buildings are completed in turn.
Before we start on site
- Arrange parking or a loading space
- Send your site hours and access windows
- For older buildings, check the asbestos register before work
Quotes
Specifications, drawings and tender packages are welcome with any enquiry, and we’ll price the work to it. For smaller jobs, photos and a description will do.
Advice
Also near Marylebone
Also in Marylebone
When something else is needed
Sealant solves a lot, but not everything, and we are upfront when that’s the case. It won’t fix:
- Cracked or crumbling render, brick or stone at the joint edges (we will tell you if so)
- Leaks through the frame itself rather than the perimeter
- Roof leaks, gutters or failed flashings that aren’t sealant joints
Not sure which it is? You can phone 01277 525 020 or send details through our quote form and we’ll tell you honestly.
Surfaces we seal
- Communal kitchens and washrooms
- Window and door perimeters on blocks
- Communal entrances and stairwells
- Balcony and threshold joints
- External wall and movement joints
- Shopfronts below residential blocks
Building owners, agents and FMs in Marylebone
As a CHAS accredited contractor and Constructionline member, we are straightforward to vet for your supplier list. We’re fully insured, and our insurance certificate can go with the quote.
Agents, factors and owners’ representatives all follow the same route: send the details, accept a fixed quote, and we carry out and guarantee the work. Keys, access and contacts can be agreed in advance.
Surface by surface
Communal areas
We keep entrances and stairs open throughout. Work is planned in sections.
Estate-wide resealing programmes
Housing associations and agents often manage many similar blocks. We quote building by building and work through them in turn.
Questions we are asked in Marylebone
Can you quote for a block close to Bond Street station?
Yes. Blocks of any size are within what we do. We work to your notice and access arrangements.
Do you work in London buildings with loading restrictions?
Yes. Booked loading bays, goods lifts and permit-to-work systems are normal for London jobs. Say when the building is occupied and when it’s quiet, and we will plan accordingly. We allow for the ULEZ, which covers every borough
Which sealant will you use?
The specification comes first, if there is one. Without one, the joint decides: how much it moves, what it bonds to and whether it’s wet, trafficked or fire-rated.
Can you work to our specification?
Yes. The specification and the manufacturer’s installation guidance are what we work to, and any queries are raised before we start.
Do you guarantee the mastic work?
Our workmanship carries a 12-month guarantee and we hold public liability insurance.
What paperwork can you provide?
Let us know your requirements: tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we’ll confirm with the quote. We are CHAS accredited and a Constructionline member.
Is it fine to apply new sealant on top of old?
No. We cut the old material out and clean the joint back before sealing, because fresh silicone will not bond with aged silicone.
After the work
Cleaning and maintenance staff play a part too. Pass these on to them:
- Look at the sunniest and most exposed elevations first
- Share the asbestos register when you send details
- Reduce knocks to communal area joints
- Avoid piecemeal callouts where you can
Where a paintable product was specified, it can be painted after curing. Silicone typically can’t be painted, so keep decorators off it.
Leaks at window perimeters spoil finishes and can affect frames. Early resealing is far simpler than repairs inside.
Blocks and managed buildings in Marylebone
In London, mastic work on a block goes through the managing agent or landlord, with notice to residents. We plan around the notices and access you arrange.
Blocks of flats and mixed-use buildings often cluster around stations such as Bond Street station, under half a mile south of Marylebone, and their window and balcony mastic tends to age at the same rate across a building. For owners of several units at places like Brompton Cross District Shopping Centre., which lies south-west of Marylebone, one programme can deal with frame and external mastic across the lot.
Marylebone is about 3 miles north-west of London, in Greater London. Our applicators travel to Marylebone for work on mastic joints. Across Greater London, 764 places are covered, including Marylebone.
Business premises anywhere in W1U, W1T and W1K are within our area. For a building on Park Lane, Duck Lane and Bruton Lane or nearby, we can quote for mastic joints. You will find Marylebone on or near the A400 and A401. Just outside Marylebone, we also work in City of Westminster (1 mile south-west), Mayfair (1 mile south), Fitzrovia (1 mile north-east), Burlington Estate (1 mile south-east) and Soho (1 mile south-east). A short drive away, we cover London (3 miles south-east), Kensington (3 miles south-west), Shoreditch (3 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles north-east) and Whitechapel (3 miles east). Marylebone is one of the busier places in Greater London, and we take on mastic joints for its commercial and public buildings.
What’s near Marylebone
We work on buildings around St Anne's Churchyard, The St Marylebone CofE School and Royal Society of Medicine Library, among other places. Nearby too are The St Marylebone CofE School (less than half a mile north-west) and The Phoenix pub (under half a mile south-east). Marylebone has its own railway station: Bond Street station. A little further out are Montfichet's Tower (2 miles east) and Twist Museum (less than half a mile south-east). Open spaces near Marylebone include Adelaide Nature Reserve and St. James's Park Lake.
Common problems we fix in Marylebone
Frames, panels and masonry expand and contract through the year, and the sealant takes up that movement. If the joint or the product wasn’t suited to the movement, it splits long before it should.
What tends to prompt an enquiry:
- Repeated reactive repairs to the same buildings
- Brittle perimeter mastic across a building
- Damp patches beside frames
- Old repairs sealed over failed mastic
Owners of student blocks near University of Westminster, under half a mile north-east of Marylebone, can schedule frame and external mastic for the summer vacation.
Before you book anyone
- Are they CHAS accredited or on Constructionline?
- Will CSCS-carded applicators be on site?
- How they’ll work around occupants
- Do they follow the manufacturer’s priming guidance?