Keston construction mastic
We carry out mastic packages for new-build and refurbishment projects in Keston and the surrounding area. Send photos or drawings for a fixed quote.
- Cracks opening in caulked internal joints
- A long mastic snag list close to completion
- Perimeter gaps outside the sealant’s range
Need construction mastic in Keston?
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
How we handle construction mastic in Keston
Since 2005 we have worked alongside main contractors, developers and fit-out firms. Quantities come off the drawings, the sequence is agreed with the site manager and the work follows the trades. To price a package in Keston, send drawings and the specification through our quote form. We work on sanitary and kitchen joints, internal decorators’ caulk and floor and skirting junctions, and the failures we’re asked to look at most are failed sealant in an existing building being refurbished and frame gaps too wide for sealant alone. One point of contact handles commercial sealant work in Keston from the first photographs to the final walk-round, whether it’s one building or several.
Construction in a London area such as Keston means working on constrained sites: limited storage, booked deliveries and access shared with other trades. Mastic is usually one of the last trades on each elevation or floor, so we keep to the programme and the order of trades the site sets.
Every job we finish is backed by a 12-month workmanship guarantee. If a joint we sealed fails because of how it was installed, we come back and put it right.
- Location
- Keston (BR2)
- Wider area
- Greater London
- Cover
- 12 months on our workmanship
- Quotes
- A fixed quote before we start
- Call
- 01277 525 020
- Updated
- 3 November 2026
Diagnose, treat, sign off
When we get to site, we report to your site contact and complete whatever induction the building runs. Floors, finishes and fittings next to the joints are covered before anything is cut or cleaned, with the work itself usually taking whatever the programme allows, since the work follows the trades as areas are released. Planning a London job such as one in Keston starts with access. Send the building rules and access times with your enquiry.
- First we look at the scope on site or from drawings.
- You receive a fixed quote covering scope, products and sequence.
- 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 straight away.
- The package is closed out, snags cleared and backed by our 12-month guarantee.
What we need from you
- Let us know about inductions and permits
- For older buildings, check the asbestos register before work
- Move anything stored against the joints
Request a quote
For a fixed quote, call the office on 01277 525 020 or email drawings and photos with the site address and an outline of the work. You can also send details through our quote form.
Advice
Why it’s worth doing now in Keston
Getting the mastic contractor involved early pays off. We can check joint widths, flag frames with gaps that won’t seal and confirm products against the specification. Leave it late and they turn up on the snag list. Repeat call-outs disrupt occupied London buildings, so cutting the old sealant out fully and doing it right once is the better route.
Pricing mastic packages depends on quantities, condition and access. Call for a quote.
Why clients in Keston choose us
- Constructionline member
- Workmanship guaranteed for 12 months
- A fixed quote before work starts
- Specification-led, product-correct work
Take a look at what affects the cost or how we’re accredited.
What else we do in Keston
For managing agents and facilities managers
Hospitality, education, healthcare, office and retail clients come to us directly as well. The work is planned around how the building runs, so the building keeps working while we do.
Agents, factors and owners’ representatives all follow the same route: send details, get a fixed quote, we seal, guaranteed. Keys, access and contacts can be agreed in advance.
Doing it in-house
For a quick touch-up, site staff may be fine, but anything bigger is another matter: a specialist works through quantities efficiently, leaves a consistent finish and backs it with a 12-month guarantee.
Putting right a botched joint often costs more than sealing it well at the start, since all of it has to come out and the faces be cleaned back again. That’s why many clients bring in a specialist from the beginning.
Facades, frames and programmes in Keston
Site traffic in Keston falls within London’s ULEZ, like everywhere else in Greater London. Deliveries are booked and storage is tight, so mastic materials come in as needed.
For contractors at a school such as Keston Church of England Primary School, sealing has to be finished before term starts. Further education sites such as Shaftesbury Nash College, 1.4 miles north-west of Keston, are extended and refurbished from time to time, with mastic often programmed into the summer break. New units and refits on sites such as Glebe Farm Business Park (0.8 miles south of Keston) need their panel and perimeter joints sealed to the specification.
Keston is about 3 miles south of Bromley, in Greater London. We cover commercial sites throughout Keston, for single jobs and planned programmes alike. Keston is one of 764 places we cover in Greater London. London is covered too, around 11 miles from Keston.
We take on mastic packages across the BR2 postcode area. Among the streets we cover are Church Road, Greys Park Close and Heathfield Road, and sites on any of them can send details for a fixed quote. We also cover Nash (1 mile west), Farthing Street (1 mile south-east), Locksbottom (1 mile north-east), Leaves Green (2 miles south) and Hayes (2 miles north-west) for mastic packages. Bigger towns within reach include London (11 miles north-west), City of Westminster (13 miles north-west), Marylebone (13 miles north-west), Kensington (14 miles north-west), St Pancras (13 miles north-west) and Shoreditch (12 miles north).
Around Keston
Around Keston, our work takes us to commercial buildings near South Park, Ravens Wood School and The Greyhound pub and the streets around them. Keston’s nearest station is Hayes (Kent) station, roughly 1.5 miles north-west. A little further out are Princess Royal University Hospital (1.1 miles east) and Bethlem Museum of the Mind (1.5 miles north). The countryside around Keston includes West Kent Golf Course nature reserve and Summer Hill.
Maintenance after handover
Keep the joints in good shape with a few simple steps:
- Release areas for mastic once other trades have finished in them
- Use the product the specification names
- Record the products used in the O&M file
- Get the mastic subcontractor involved early in the programme
The package carries our 12-month guarantee for workmanship. Damage by others isn’t a workmanship fault, so protecting sealed areas matters.
Snag items left to the last week put handover at risk. A planned close-out through each area as it completes keeps the list short.
Questions we are asked in Keston
Will you plan work around the academic year at somewhere like Shaftesbury Nash College?
Yes. Education sites typically want the work in vacations or in phases during term, and we plan to suit. We are CHAS accredited and a Constructionline member, and paperwork such as RAMS is confirmed with the quote.
Can you work at a site such as Glebe Farm Business Park, by Keston?
Yes. We cover Keston and the area around it, including industrial estates, business parks and retail parks such as Glebe Farm Business Park. A few photos and the unit address let us price the work.
Can you work plot by plot or floor by floor?
We seal plot by plot or floor by floor as areas are released. The sequence is agreed with the site manager at the start and updated as the programme moves.
Do you use the sealant named in the specification?
We work to the specification and the manufacturer’s installation guidance. Preparation, backing and depth follow the product guidance.
Who decides which product is used?
If the job is specified, we follow the specification. If not, we choose for the movement, the surfaces and the conditions, in line with the manufacturer’s guidance.
Is it fine to apply new sealant on top of old?
No. Failed sealant is removed and the faces cleaned back to sound, dry material first, because fresh silicone will not bond with aged silicone.
Can fire-rated sealing at service penetrations be included?
Fire-rated sealant can be included where it’s specified, installed to the product’s tested detail. The design and sign-off belong to the designer, fire engineer or building control.
How the job changes by surface
Internal decorators’ caulk
Caulking is often done in a hurry by whoever’s on site. A neat, consistent caulk line makes the decorators’ job quicker.
External facade and movement joints
Many facade substrates need a primer before sealing. Primer goes on where the sealant maker calls for it and work only when conditions suit.