Construction and new-build mastic in Deptford, Greater London
Mastic packages for new-build and refurbishment projects in Deptford. CHAS accredited and fully insured, with a 12-month guarantee.
- Sanitary sealant damaged by following trades
- Missed perimeter joints on a new elevation
- Early adhesion failures on new external joints
Construction mastic near Deptford
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
Construction mastic for commercial buildings in Deptford
Buyers, tenants and clients notice sealant lines long before they notice the structure. A smeared bead round a window or a gap behind a worktop ends up on the snag list and clearing them late eats into the handover window. Our aim is joints that pass at the first inspection, area by area through the programme. We work on cladding and panel joints, sanitary and kitchen joints and brick and block movement joints, and the failures we are asked to look at most are frame perimeters left unsealed or poorly sealed and early adhesion failures on new external joints. Facilities teams, main contractors and managing agents in Deptford tend to want the same three things: a clear scope, tidy work and joints that don’t fail again.
A great deal of London construction is refurbishment of occupied or part-occupied buildings, alongside new blocks. Replacement windows, recladding and fit-outs leave perimeter and facade joints to seal, often next to people still using the building.
Building owners and contractors get the same cover: twelve months on the work we carried out. Faults in the structure, damage and other trades’ work fall outside it, and we say so plainly.
- Place
- Deptford (SE8, SE10, SE14)
- Wider area
- Greater London
- Cover
- A 12-month guarantee
- Price
- A fixed quote before we start
- Phone
- 01277 525 020
- Updated
- 3 November 2026
Common questions from Deptford clients
Is hospital work, at somewhere like University Hospital Lewisham, something you do?
Yes. We work in healthcare settings as well as offices and schools. Work is phased so departments keep running, under the site’s own rules.
Could you schedule work at a campus like University of Greenwich - Greenwich Campus for the vacation?
Yes. Tell us the term dates, vacation periods and access windows, and we will plan the work around them. Any paperwork you need, from RAMS to our insurance certificate and CSCS details, is confirmed with the quote.
Do you take on multi-site work?
Yes. Several buildings can share a single quote, and you deal with one contact throughout.
Can weather delay the job?
For external joints, yes. Sealant needs a dry joint and a temperature within the product’s range, so damp, frosty or very cold days can stop external work. Internal work is rarely affected.
What if there’s asbestos in the old mastic?
Managing asbestos is the dutyholder’s responsibility, so we will ask for the register before work on an older building. Work pauses if suspect material is found, until it has been tested.
Is colour matching possible?
In many cases, yes. Many products come in a range of standard colours, and matching to RAL references or surrounding finishes is often possible. We’ll confirm the colours available for the specified product.
How soon can the area be used again?
Curing time varies by product, and we confirm it on the day.
General trades versus a specialist
Certain joints really need a specialist: fire-rated seals that must follow a tested detail, trafficked floor joints and external movement joints among them. Getting these wrong typically costs more in the end than doing them right.
What you see is the finished bead, but most of the work is hidden. Correct depth, the right primer and a sealant matched to the movement are easy to get wrong without experience.
After the work
After handover, these steps help:
- Note which sealant went where at handover
- Ask for joint and product checks before the package is urgent
- Stick to the specified sealant rather than a generic substitute
- Brief following trades on areas that have been sealed
After we’ve sealed an area, it helps to keep other trades from damaging the joints. New beads should be left to cure before cleaning or decorating nearby.
External joints sealed in poor weather are a common cause of early failure. Waiting for a dry joint and the right temperature is better than redoing work, so we plan external work with that in mind.
Surface by surface
Window and door perimeters
Perimeter joints between frames and the structure are the weather line on any new building. We use the specified perimeter sealant, normally a low-modulus neutral-cure silicone.
Fire-rated sealant where specified
Where the specification calls for fire-rated or intumescent sealant around service penetrations or linear gaps, we install it to the manufacturer’s tested detail. Fire stopping design belongs to the designer and building control; we work to the specification and the manufacturer’s installation guidance.
From enquiry to sign-off
Diagnose, treat, sign off: every visit follows that pattern. We inspect the joints and confirm what’s in scope, then we prepare and seal each joint with the specified product, and the job ends with a walk round and sign-off. All of Greater London is in the ULEZ, and kerbside space in Deptford can be scarce. Let us know about any on-site parking or loading arrangements when you send the job details.
- We walk the site or review drawings to understand the package.
- 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.
- Final snagging is completed and the 12-month guarantee applies.
Preparing the site
- Flag any permit to work we will need
- Make sure the joints can be reached
- Let building users know which areas are affected
Quotes
Photos, drawings or a schedule of the joints and a fixed quote comes back to you. Where a site visit makes more sense, we’ll arrange one.
Read more
Common problems we fix in Deptford
A joint without backing rod or bond-breaker often fails early. Fixed to three faces, the sealant rips the first time the joint opens.
Site and facilities staff are often the first to spot these:
- Sealant knocked or painted over by other trades
- Failed sealant in an existing building being refurbished
- Internal caulk splitting as the building dries out
- Window and door perimeters that won’t pass inspection
New wings at hospitals like University Hospital Lewisham (1.7 miles south of Deptford) bring long runs of window and panel joints to seal.
Comparing quotes
- Do they follow the manufacturer’s priming guidance?
- The terms of the workmanship guarantee
- Are they CHAS accredited or on Constructionline?
- Which product they’ll use, and why it suits the joint
Sites and facades in and around Deptford
Deptford has plenty of hotels close by, all within 2 miles. Hotel schemes tend to have fixed reopening dates, so the mastic is programmed tightly with the other trades. Site traffic in Deptford 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.
On a campus such as University of Greenwich - Greenwich Campus, 0.9 miles east of Deptford, new teaching buildings and residences are typically built and refurbished around the academic year. Hotels like King William Hotel, 1.4 miles to the east of Deptford, rarely close for long, so refurbishment mastic is phased floor by floor.
Deptford is about 3 miles south-east of Whitechapel, in Greater London. Anywhere in SE8, it works the same way: send details, get a fixed quote, we seal, and the work is guaranteed. We work across 764 places in Greater London.
If you need construction mastic in SE8, SE10 and SE14, the process matches everywhere else we work: send details, get a quote, we seal, guaranteed. Buildings on Mill Lane, Dixon Road and Clare Road are within our area. Access to Deptford is via the A2209 among other routes, so getting applicators and materials to site is simple. If your building is just outside Deptford, we cover New Cross (1 mile south-west), St Johns (1 mile south), Millwall (1 mile north), Isle of Dogs (1 mile north-east) and North Greenwich (1 mile north-east). A short drive away, we cover London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north-west).
Landmarks near Deptford
Recent enquiries here include premises near Addey and Stanhope School, Sue Godfrey Nature Park and Deptford Arms, among other places. Deptford has its own railway station: Deptford station. Nearby you’ll also find Greenwich Castle (1.1 miles east) and Lewisham Shopping Centre (1.3 miles south-east). Green spaces nearby include Sue Godfrey Nature Park and Tower Hill.
Also in Deptford
What happens if it’s left?
Some packages split mastic across the window fitter, kitchen fitter and plumber. The result tends to be uneven finishes and arguments about who should seal what. A single mastic package gives one point of responsibility. Getting scaffold, permits or access booked in Deptford takes effort, so while access is arranged it pays to renew all failing joints, not just the worst.
Pricing mastic packages depends on how many there are, their condition and the access, and any specification that applies. Call for a quote.
Why appoint us
- One phone line for London, the South East and Scotland
- Colours chosen to suit frames, cladding or finishes where possible
- Public liability insurance in place
- Standard and matched colours in many product ranges