Greater London · England
External & façade joints in Crossness, Greater London
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Crossness and across Greater London. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Sealant pulling away from one side of the joint
- Water getting into walls through failed joints
- Gaps where render, brick and frames meet
External mastic for homes and businesses in Crossness
A movement joint is a deliberate break that lets a wall expand and contract. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. We work on concrete & block, brickwork movement joints and façade panels, and people most often call us about rigid filler in a joint that should flex and failed sealant between panels on a façade.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Crossness, tell us how high the joints are and how to reach the back of the building.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Where
- Crossness (SE2, SE28, DA18)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
When to call us in Crossness
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the next time the wall moves, it splits or pulls away.
It’s worth asking for a quote if you see:
- Failed sealant between panels on a façade
- Movement joints filled with mortar instead of sealant
- Joints with sealant missing in places
- Old sealant gone brittle and cracked
As a London address, Crossness can be tricky for parking: let us know about parking bays, permits or a driveway.
What to look for in a quote
- Who does the work, and how experienced they are
- How the joint is cleaned and prepared
- Whether they’re fully insured
- What happens if the job turns out different
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Have failed joints looked at early
- Keep movement joints as flexible joints, not mortar
- Tell anyone working on the walls about the movement joints
- Don’t let climbing plants root in the sealant
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
Small splits are the time to act. At that stage it’s a simple cut out and reseal with no damage behind it to deal with.
External mastic in Crossness: local notes
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Rainham Hall (about 2.8 miles north-east) are a reminder that the area around Crossness has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth.
For an older house near a landmark such as Church of the Cross, older walls, gutters and the joints where extensions meet them need a flexible sealant. Letting a property close to Abbey Wood station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Crossness is about 2 miles north-west of Erith, in Greater London. Crossness gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across Greater London, we cover 764 places, Crossness among them. For nearby work, see our London page (10 miles or so).
Jobs for external mastic in SE2, SE28 and DA18 works the same way as everywhere else we cover. Local streets include Kale Road, Haldane Road and Seacourt Road, all of which we cover. You will find Crossness on the A2016, so it’s easy for us to get to with everything needed for external mastic. We also cover the places around Crossness: Thamesmead (1 mile north-west), Dagenham Dock (1 mile north), Barking Riverside (2 miles north-west), Hornchurch Marshes (2 miles north-east) and Dagenham Green (2 miles north). We also work in nearby towns such as London (10 miles west), City of Westminster (12 miles west), Marylebone (12 miles west), Kensington (14 miles west), St Pancras (11 miles west) and Shoreditch (9 miles west).
Near you in Crossness
Around Crossness, our work takes us to homes and buildings near Lesnes Abbey Woods, Harris Garrard Academy and Belvedere Working Mens Club pub, among other places. For rail, the closest station is Abbey Wood station, roughly 0.8 miles south-west. Nearby you will also find Erith and District Hospital (2.1 miles south-east) and Gallions Reach Shopping Park (2.4 miles west). Not far away are Crossness Nature Reserve.
Landlords, agents and businesses in Crossness
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Housing providers, facilities teams and property managers book us too in Crossness and across Greater London. Several sites can go on one quote.
What we can’t put right
A few problems are outside what sealant work can do:
- Failed render or damaged cladding panels
- Structural movement, which needs a surveyor or engineer
- Walls that need new movement joints cut into them
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think.
Surfaces we seal
- Render & cladding joints
- Copings & trims
- Brickwork movement joints
- Façade panels
- Concrete & block
- Joints between brick and frames
Places near Crossness
More services for Crossness
Different surfaces, different methods
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it, or one the system allows. Tell us what the building has when you get in touch.
Copings and trims
Coping joints that leak let water straight down into the wall. Sealing them early saves the wall below.
Should I try it myself first?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Questions from Crossness
Is parking an issue for external mastic in Crossness?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot.
Is Crossness in your area for external mastic?
Yes, Crossness is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
Will there be a smell?
There can be a smell while the sealant cures, but it fades. Ventilation helps.
Is it messy?
Tidy work is part of the job. Nearby surfaces are protected.
Will the new joint stand out?
The sealant colour is picked to suit the wall. Exterior sealants come in a good range of colours.
Is the work guaranteed?
Yes. Every job comes with our one-year guarantee.
Is it OK to seal over old sealant?
No. The old sealant always comes out first.
Do I have to be there?
That depends on where the joints are. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.
How it works
A visit follows a simple pattern: we look at the joints together, protect the area around them, do the work and tidy away. It usually takes a few hours for a handful of joints, longer for a whole elevation. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Mention any parking rules near the property
- Mention any tricky access
- Mention any leaks or damp you’ve noticed
Ask for a quote
Asking for a quote is easy: let us know what needs doing and where, and roughly how big it is. A few photos by email make the job easier to understand.