Southwark construction mastic
Our CSCS-carded applicators take on mastic packages for new-build and refurbishment projects in Southwark and the surrounding area. Send photos or drawings for a fixed quote.
- A long mastic snag list close to completion
- Frame perimeters left unsealed or poorly sealed
- Different trades sealing to different standards
Construction mastic in Southwark
Photos, a specification or a quick description of the joints is enough to start a fixed quote.
About our construction mastic in Southwark
External mastic depends on the weather in a way most internal trades don’t. Each sealant has a temperature range, and damp, frost or condensation on frames stops work, so we plan elevations with the forecast and the programme in mind. Internal areas can typically carry on while the outside waits. Site teams most often ask us about cracks opening in caulked internal joints and mastic snags holding up handover, on sanitary and kitchen joints, brick and block movement joints and window and door perimeters. Whoever orders the work in Southwark, the brief is usually the same: a clear scope, tidy work and joints that don’t fail again.
Building sites in London tend to be tight: small compounds, delivery slots and shared hoists and scaffold. We fit around the programme, sealing each elevation or floor as other trades hand over.
Our workmanship is guaranteed for 12 months, wherever the site is. If our installation lets you down in that time, we return and fix it.
- Where
- Southwark (SE1, SE11)
- Region
- Greater London
- Guarantee
- 12 months on our workmanship
- Quote
- A fixed quote before we start
- Call
- 01277 525 020
- Last updated
- 3 November 2026
When to call us in Southwark
Frames installed with uneven gaps make perimeter sealing harder. Every product has limits on how wide a joint it can bridge, so gaps outside that range need sorting by the installer first. Better to raise it at the start than seal a joint that’s bound to fail.
These are often picked up first by site or facilities staff:
- New external sealant already peeling away
- Frame gaps too wide for sealant alone
- Caulk cracking where joints are moving more than expected
- Existing joints on a refurb that need cutting out and resealing
Hotels like The Bridge Hotel (to the south-west of Southwark) rarely close for long, so refurbishment mastic is phased floor by floor.
Before you book anyone
- How they handle RAMS and site documents
- Health and safety accreditation such as CHAS
- Whether old or failed sealant will be cut out, not overlaid
- Whether their applicators hold CSCS cards
Aftercare for building managers
Problems stay small when the joints are checked regularly. Specifically:
- Brief following trades on areas that have been sealed
- Check frame gaps are within the sealant’s range before sealing
- Release areas for mastic once other trades have finished in them
- Put any product change through the designer first
Tell the builders’ clean team which areas have new sealant. Scrapers used on frames and worktops can nick or lift a new bead so keep them off the joints.
One unsealed frame can let water into finished internal areas. That normally means redoing finishes in a completed area and possibly a delayed handover. Checking perimeters before internal finishes go on avoids it.
Different surfaces, different methods
External facade and movement joints
Movement joints in the facade are sealed with a product suited to the expected movement. Depth is controlled with backing rod so the bead bonds to two sides only.
Snagging before handover
Snags normally come from damage by following trades, missed joints or poor earlier work. Snagging can be included or priced separately.
Our process
Diagnose, treat, sign off: every visit follows that pattern. We inspect the joints and confirm what’s in scope, then the work is carried out to the specified product and detail, and the job ends with a walk round and sign-off. In Southwark, most buildings stay in use during the work, so zones and timings are agreed with whoever manages the building. Phased work keeps the rest of the building in use.
- We walk the site or review drawings to understand the package.
- A fixed quote sets out scope, products and phasing.
- Paperwork is agreed and applicators are inducted on site.
- We seal plot by plot or floor by floor in line with the programme.
- Problems we find, such as oversized gaps, are raised right away.
- Final snagging is completed and the 12-month guarantee applies.
Before we start on site
- Share the asbestos register for older buildings
- Agree which areas must stay open
- Warn occupants and staff about the work
Quotes
The quickest route to a quote is a few photographs and the site postcode. Upload them with the quote form, or call the office on 01277 525 020 or email us if you’d rather talk the job through.
Related advice
Common questions from Southwark clients
Is a hospital such as Guy's Hospital somewhere you can work?
Yes, hospitals are one of the sectors we cover. The estates team’s permit system and infection-control rules come first, and the work is planned around them.
Do you take on jobs in Southwark where loading and access are tightly controlled?
Yes, we plan every London job around the building’s own access rules. Send the building rules and access times with your enquiry.
How many days will you need on site?
The duration is planned around your programme and the access we are given. We’ll give you an estimate of time on site when we quote.
Do you offer coloured sealant?
Often, yes. Sealants are made in a wide range of standard colours, and matching to RAL references or nearby finishes is commonly requested. We confirm what’s available for the specified product when we quote.
Can you send site paperwork?
Requirements differ from site to site, so list what you need, whether RAMS, insurance or CSCS details, and we will confirm with the quote.
Do you cover Southwark?
Yes. We take on work across Southwark, with one number for every area we cover.
Do you have public liability insurance?
Yes. We’re fully insured, and the certificate can go with your quote.
Towns and villages near Southwark
Also in Southwark
Site staff or a sealant specialist?
Paperwork matters too. Main contractors and clients often ask for CSCS cards, RAMS and insurance details, and we will confirm the paperwork you need with the quote.
Using site staff can make sense for a small touch-up, but larger jobs are different: a specialist brings efficiency, a consistent finish and a 12-month guarantee.
Construction mastic around Southwark: how the place shapes the job
A good number of hotels sit less than 2 miles from Southwark. Hotel refurbishments often run to tight programmes between busy periods, and perimeter and sanitary sealant has to keep up. As part of Greater London, Southwark is inside the ULEZ, which applies to every van on site. London sites also mean booked deliveries and limited storage, which the mastic programme has to allow for.
Recladding or extending a unit at a site like Southwark Bridge Business Centre, under half a mile north of Southwark, brings panel joints and frame perimeters into the programme. For contractors on a campus like London South Bank University, less than half a mile south-west of Southwark, facade and perimeter sealing has to fit around students and term dates.
Southwark is about 0 miles north-west of London, in Greater London. Southwark sits inside our coverage and the rest of Greater London, and jobs here get the same fixed quote and 12-month guarantee as anywhere else. We work across 764 places in Greater London, large and small.
Anyone looking for construction mastic in SE1 and SE11 gets the same process as the rest of our area: details, then a fixed price, then sealing and a 12-month guarantee. Streets here include Borough Square, Trinity Church Square and Merrick Square. Access to Southwark is via the A300 and B240. If your building is just outside Southwark, we cover Tower Hill (1 mile north-east), City of London (1 mile north), Aldgate (1 mile north-east), Bishopsgate (1 mile north-east) and Barbican Estate (1 mile north). A short drive away, we cover City of Westminster (3 miles west), Kensington (5 miles west), Walthamstow (7 miles north-east), Hampstead (5 miles north-west), Ruislip (14 miles west) and Brompton (3 miles west).
Landmarks near Southwark
Locally, jobs take us to sites close to London School of Musical Theatre, Little Dorrit's Playground and St Mary-at-Hill, among other places. Also close by are Ark Globe Academy (under half a mile south-east), The BFI Reuben Library (0.9 miles north-west) and The Gladstone Arms (less than half a mile north-east). The nearest railway station is Elephant & Castle station, roughly 0.5 miles south of the centre. A little further out are Gabriel's Wharf (0.7 miles north-west) and Baynard's Castle (0.8 miles north). The countryside around Southwark includes Ludgate Hill and Bellenden Road Nature Garden.
What we can’t put right
Being straight saves everyone time. New sealant won’t cure:
- Deciding which fire-stopping product a penetration needs
- Damage to finishes by other trades after we have sealed
- Defective windows, doors or glazing units (the supplier or installer’s job)
If you’re not sure, just speak to us on 01277 525 020 or email a schedule or drawings and we will give you a straight answer before you book.
Surfaces we seal
- Sanitary and kitchen joints
- Window and door perimeters
- Floor and skirting junctions
- Brick and block movement joints
- Internal decorators’ caulk
- Cladding and panel joints