St Johns mastic sealing
Mastic sealing in St Johns, backed by over 20 years in commercial sealing. Fully insured, with a 12-month guarantee.
- Occupiers reporting cold air round windows
- Old repairs sealed over failed mastic
- Open joints in brickwork or panels
Mastic sealing for businesses in St Johns
Photos, a specification or a quick description of the joints is enough to start a fixed quote.
How we handle mastic sealing in St Johns
For blocks and buildings in St Johns and across Greater London, the process is the same: send details, get a fixed quote, we seal, and the work is guaranteed. A list of buildings, a few photos and approximate joint numbers are enough for a quick quote, and site visits can be arranged. If you are dealing with estate-wide sealant that is simply worn out and patchy repairs in mismatched sealant, we can put it right. One point of contact handles commercial sealant work in St Johns from the first photographs to the final walk-round, whether it’s one building or several.
For managing agents in St Johns, resident access, notice periods and the building’s rules shape the job. Work is planned with the agent so residents get notice and access is arranged in advance.
Every job ends the same way: guaranteed. You get a 12-month guarantee on our workmanship, and the quote explains what it covers.
- Where
- St Johns (SE13, SE10, SE8)
- Region
- Greater London
- Guarantee
- A 12-month guarantee
- Quote
- Quoted before any work starts
- Phone
- 01277 525 020
- Updated
- 3 November 2026
Questions about St Johns
Can you cope with the access rules in a London building?
Yes, most London buildings have access rules of some kind, and we plan around them. The building manager’s rules go straight into our method. We allow for the ULEZ, which covers every borough
Do you work in occupied care homes around St Johns?
Yes. We work around residents’ routines, a room or two at a time. Tell us about any infection-control or safeguarding requirements and we’ll work to them.
How soon can the area be used again?
That comes down to the sealant and the temperature. Some products skin over quickly but need longer to cure fully, and we confirm it before leaving site.
How do we ask for a quote?
You can use the quote form on this site; alternatively, ring 01277 525 020 or email drawings and photos. Include photographs or drawings if you have them.
Does weather matter for sealant work?
For external joints, yes. The joint has to be dry and within the product’s temperature range, so damp, frosty or very cold days can stop external work. Inside work is seldom held up.
Do you do block-wide mastic programmes?
Yes. Each building is inspected, quoted and scheduled in turn, and the programme can start with the worst.
What will the job cost?
Each job is quoted on its own details. For yours, give us a call on 01277 525 020 or email the details over with a description of the work.
Also in St Johns
Why deal with it now?
Reacting to every complaint means sending someone out block by block. Planned resealing covers a whole building or estate in one go and is simpler to manage and budget. In a London building, a failed joint rarely affects only one party. Dealing with it early is simpler for everyone.
A quote for mastic joints depends on quantities, condition and access, plus any specification you are working to. Ask us for a fixed quote.
Why us?
- Fully insured, including public liability cover
- Commercial sealant work since 2005
- Colours chosen to suit frames, cladding or finishes where possible
- Our applicators hold CSCS cards
Take a look at what affects the cost and our accreditations.
How the job changes by surface
Planned maintenance
Planned resealing replaces emergency callouts and keeps budgets predictable.
Estate-wide resealing programmes
Housing associations and agents often manage many similar blocks. We quote building by building and work through them in turn.
Common problems we fix in St Johns
Buildings move with temperature and moisture, and the sealant takes up that movement. A joint that was too narrow, too thin or the wrong product can’t cope long before it should.
It’s worth sending us details if you spot any of the following:
- Leaks at window and door perimeters
- Mastic failing across several blocks on an estate
- Damaged joints in communal entrances and corridors
- Draughts at frames across a block
For owners of several units at places like Brookmarsh Industrial Estate, 0.7 miles to the north of St Johns, one programme can deal with frame and external mastic across the lot.
Questions to ask before you book
- Is the sealant right for the movement and the substrate?
- Will CSCS-carded applicators be on site?
- Will RAMS and insurance details be available?
- What level of public liability insurance do they hold?
On site: what to expect
Site rules come first: signing in, inductions and any permit to work. With the paperwork done, we take the joints in the sequence agreed with you, and each area is checked before we leave it. In St Johns, most buildings stay in use during the work, so we agree zones and timings with the building or facilities manager. Areas are handed back as each section is finished.
- We inspect each building and record the joints that have failed.
- You get a fixed quote, per block or for the whole programme.
- We agree the programme and dates with you.
- Failed sealant is removed and the faces prepared.
- New sealant goes in with backing rod and primer where needed.
- Each building is checked and signed off with the 12-month guarantee.
Before we start on site
- Send your site hours and access windows
- Arrange parking or a loading space
- Agree which areas must stay open
Request a quote
Need a figure for a tender or a budget? We will quote against your scope and drawings that you can work with. If you have questions first, call 01277 525 020 or use the quote form.
Read more
For managing agents and facilities managers
CHAS accredited and a Constructionline member, we are straightforward to vet for your supplier list. Our insurance certificate can be sent along with the quote.
We take on planned maintenance as well as one-off repairs: working through a building or an estate in stages that fit your budget. St Johns can form part of a wider programme.
Planned mastic for St Johns portfolios
Four care or nursing homes sit less than 2 miles from St Johns. Care home owners need frame and external mastic kept sound without unsettling residents. In London, mastic work on a block goes through the managing agent or landlord, with notice to residents. We fit the programme to your notice periods.
For agents with blocks near St Johns station, under half a mile to the south of St Johns, a block-wide mastic programme deals with frames, balconies and entrances in one go. Churches, halls and community buildings such as Church of St John are looked after by trustees and committees like any other owner, and their frames, doors and external joints need mastic renewed in time.
St Johns is about 4 miles south-east of London, in Greater London. If you’re looking for mastic sealing in St Johns, we can help, as we do across Greater London. St Johns is one of 764 places we cover in Greater London for mastic joints.
We cover the SE13, SE10 and SE8 postcode districts. Streets here include Avon Road, Mill Lane and Clare Road, and sites on any of them can send details for a fixed quote. With the A2210 and A2211 nearby, St Johns is easy to get to with materials and equipment. Just outside St Johns, we also work in New Cross (1 mile west), Deptford (1 mile north), Lewisham (1 mile south-east), Telegraph Hill (1 mile west) and Ladywell (1 mile south). Bigger towns within reach include London (4 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (6 miles north-west) and Shoreditch (5 miles north-west).
Near you in St Johns
In St Johns, that means premises near Wickham Arms, Brookmill Park and Addey and Stanhope School. You’ll also find St. Paul's (0.7 miles north) and Laban Centre (0.8 miles north). St Johns has its own railway station: St Johns station. A little further out are Fan Museum (0.9 miles north-east) and Lewisham Shopping Centre (0.7 miles south-east). The countryside around St Johns includes Brookmill Road Local Nature Reserve and Tower Hill.
When something else is needed
Honesty saves time and money. New sealant won’t cure:
- Broken glass or failed sealed units
- Asbestos-containing sealant, which we don’t remove
- Leaks through the frame itself rather than the perimeter
Not sure which it is? You can give us a call on 01277 525 020 or email us and we’ll tell you honestly.
Where we work in St Johns
- Communal kitchens and washrooms
- External wall and movement joints
- Communal entrances and stairwells
- Window and door perimeters on blocks
- Shopfronts below residential blocks
- Balcony and threshold joints