St James's mastic sealing
Work needed on a mastic joint in St James's? We assess it, carry out the work and guarantee our workmanship for 12 months.
- Cracked, hardened mastic round windows on a block
- A mix of products and colours from past repairs
- Draughts at frames across a block
Mastic sealing across St James's
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 St James's
In buildings from before 2000, some old mastics contain asbestos. We check the asbestos register or survey before any old sealant is cut out, and work stops for testing if there’s any doubt. Removing asbestos-containing material isn’t something we do. Site teams most often ask us about water getting in round frames after rain and brittle perimeter mastic across a building, across communal kitchens and washrooms, communal entrances and stairwells and external wall and movement joints. A single leaking joint is often how a building in St James's first comes to us: we look at the rest while we’re there and tell you what we find.
For managing agents in St James's, resident access, notice periods and the building’s rules shape the job. We work to the agent’s notice and access plan, so residents know what’s happening.
Our workmanship is guaranteed for 12 months. If our installation lets you down in that time, we return and fix it.
- Place
- St James's (W1F, W1D, W1J)
- Region
- Greater London
- Cover
- 12 months on every job
- Quotes
- Quoted before any work starts
- Telephone
- 01277 525 020
- Last updated
- 3 November 2026
Keeping the joints sound
Problems stay small when the joints are checked regularly. Specifically:
- Prioritise elevations facing the weather
- Encourage occupiers to report problems at frames
- Avoid piecemeal callouts where you can
- Protect low-level joints in entrances
Ask residents or tenants to report draughts or leaks round windows early. A quick report keeps a small repair small.
Failed mastic often goes unnoticed until heavy rain finds it. Resealing when cracking first shows avoids water damage and the complaints that come with it.
FAQs: St James's
Can you quote for a block close to London Charing Cross station?
Yes. Blocks of any size are within what we do. Give us the building’s details and say how residents are notified, and we will quote and plan to suit.
Will you take on work at estates like Grand Vitesse Industrial Estate, close to St James's?
Yes. Our area takes in St James's and its surroundings, with estates and business parks such as Grand Vitesse Industrial Estate included. A few photographs and the unit address let us price the work.
What about access for upper-floor joints?
Access is discussed and agreed before the quote is fixed. Tell us the building height and any access already in place, and we will tell you how we’d approach it.
How long do sealant joints last?
It depends on movement, UV and weather, cleaning, traffic and the product. Treat them as maintenance items and inspect them regularly.
Do you seal on top of existing sealant?
No, never. Overlaying old sealant is a frequent cause of early failure, so everything comes out first.
When can the area be used after sealing?
That comes down to the sealant and the temperature. Some take light use quickly, others need longer to cure, and we confirm it before leaving site.
Can weather delay the job?
It can, for external work. Wet joints and cold, damp or frosty conditions stop the sealant bonding properly, so external work may be moved if conditions aren’t right. Internal work is far less affected.
What the job involves on each surface
Planned maintenance
Mastic wears out like any building component; how fast comes down to movement, weather, UV and the product. Inspecting joints regularly keeps programmes on track.
Communal areas
Low-level communal joints get damaged more than most, so they often need renewing sooner.
How a job runs
Our CSCS-carded applicators arrive with the sealants, primers and backing rod the job calls for. Any old material is cut back to clean, sound faces, primer goes on where the manufacturer specifies it, and each bead is tooled to a neat concave finish. In St James's, most buildings stay in use during the work, so we agree zones and timings with the building or facilities manager. Phased work keeps the rest of the building in use.
- We check the asbestos register for older buildings and look at the joints.
- The products and programme are set out in a fixed quote.
- We strip out the old sealant.
- Joint faces are cleaned, backed and resealed.
- Buildings are completed in turn.
What we need from you
- Point out any areas we must not close
- Arrange parking or a loading space
- Send any specification or drawings in advance
Quotes
Photos, drawings or a schedule of the joints and a fixed quote comes back to you. If the job needs a look first, we’ll arrange a site visit.
Advice
Looking after buildings in and around St James's
In London, mastic work on a block goes through the managing agent or landlord, with notice to residents. Our programme follows the access you agree with residents.
Site managers at schools like Soho Parish CofE Primary School can fit frame mastic into the summer works. Owners of student blocks near University of Notre Dame (less than half a mile east of St James's) can schedule frame and external mastic for the summer vacation. If you own or manage units on a site such as Grand Vitesse Industrial Estate (1.4 miles east of St James's), failed mastic on frames, door surrounds and external joints can be dealt with unit by unit.
St James's is about 1 mile south-east of City of Westminster, in Greater London. Businesses, contractors and managing agents in St James's use us for work on mastic joints. 764 places across Greater London fall within our area, St James's among them.
Business premises anywhere in W1F, W1D and W1J are within our area for mastic joints. Streets here include Duck Lane, Bruton Lane and Bridle Lane, and sites on any of them can send details for a fixed quote. Being close to the A4 and A400, St James's is straightforward for us to reach. If your building is just outside St James's, we cover Chinatown (1 mile north), Charing Cross (1 mile east), Soho (1 mile north), West End (1 mile north-east) and Burlington Estate (1 mile west). Bigger towns within reach include Kensington (3 miles west), Shoreditch (3 miles north-east), Walthamstow (7 miles north-east), Hoxton (3 miles north-east), Whitechapel (3 miles east) and Hampstead (4 miles north-west).
What’s near St James's
In St James's, that means premises near LITE Regal International School, Tom Cribb pub and London Library and the streets around them. Nearby too are Harris Westminster Sixth Form (0.6 miles south) and St Anne's Churchyard (less than half a mile north). There’s a railway station in St James's itself: London Charing Cross station. A little further out are The Museum of Practical Geology (less than half a mile north-west) and Montfichet's Tower (1.4 miles east). Not far away are St. James's Park Lake and Ludgate Hill.
For managing agents and facilities managers
FMs need a contractor who is easy to get on site. Let us know the documents you need (RAMS, insurance certificate, CSCS details) and we will confirm them with the quote.
Main contractors use us as their sealant subcontractor on new-build and refurbishment projects. We work to your programme, your specification and your site rules, with CSCS-carded applicators on site.
What sealant work can’t fix
Being straight saves everyone time. Fresh joints won’t solve:
- Water coming in from the roof or rainwater goods
- Substrate edges that need repairing first
- Leaks through the frame itself rather than the perimeter
If in doubt, phone 01277 525 020 or send photos by email and we will say what we think.
Joints and surfaces we work on
- Shopfronts below residential blocks
- Window and door perimeters on blocks
- Communal kitchens and washrooms
- External wall and movement joints
- Balcony and threshold joints
- Communal entrances and stairwells
What happens if it’s left?
Failed perimeter mastic lets cold air in around frames and the windows usually get the blame. In many cases, new perimeter sealant deals with it when the frames themselves are sound. In St James's, each extra visit means more notices, permits and disruption, so cutting the old sealant out fully and doing it right once is the better route.
The product called for affects the cost, and so does the preparation, from cutting out to priming and backing rod. Access, phasing and site requirements come into it too.
What you get with us
- Standard and matched colours in many product ranges
- 12-month guarantee on workmanship
- Matching to RAL references, product permitting
- Our applicators hold CSCS cards