Greater London · England
External Mastic in Dagenham
External mastic in Dagenham from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Weeds or debris growing in open joints
- Hard, crazed mastic that has stopped moving
- Movement joints filled with mortar instead of sealant
External mastic for homes and businesses in Dagenham
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we will confirm what access is needed. Common call-outs are for moss and dirt in joints with no sealant left and old sealant gone brittle and cracked, across concrete & block, brickwork movement joints and render & cladding joints.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so one failed joint can cause damp for more than one household. In a converted house in Dagenham, it’s worth checking who is responsible for the outside before booking.
You get a 12-month guarantee, the same in Dagenham as everywhere else we work.
- Where
- Dagenham (RM10, RM9, RM13, RM7)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
What happens on the day
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, do the work and tidy away. It generally takes anything from a few hours to several days, depending on the building. In Dagenham, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Mention any tricky access
- Let us know if you’ve seen damp or leaks
- Move anything stored near the joints
Ask for a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. Whenever you’re ready, phone 0345 464 0079 or drop us an email.
Related advice
Towns and villages near Dagenham
Other services in Dagenham
Looking after it afterwards
So the new joints stay in good condition:
- Show decorators and builders where the movement joints are
- Leave the joints unpainted unless we’ve said otherwise
- Don’t let climbing plants root in the sealant
- Wash walls gently around the sealant
Do not let soil, plants or ivy build up against the new joints. Anything that holds water against the joint wears it out sooner.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years.
What happens if it’s left?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That matters on brick, render and concrete, which can be weaker at the face. Too stiff a sealant can pull at the edges and break them. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
The cost depends on the amount of work, how hard the old material is to remove and access to the work. We give a clear quote before any work starts.
Why us?
- We are fully insured
- Trusted Arbo and Everbuild sealants
- Rated 4.9 stars on Google
- Neat joints and a tidy finish
See our cost guide and what customers say.
What affects the cost of external mastic
There’s no set price list. The quote depends on:
- How much old sealant there is and how hard it is to remove
- The product the joint needs
- Any mould that needs treating
- How easy the joints are to reach
Leaving a failed joint generally makes the job bigger, not smaller. If you are unsure, call 0345 464 0079 or drop us an email for an honest opinion and a quote.
What to tell us for a quote
Before you ask for a quote, have a think about:
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- The type of property
- The address or postcode of the job
To get a quote, phone 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We’ll give you a clear price before any work starts.
Landlords, agents and businesses in Dagenham
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Common problems we fix in Dagenham
Poor preparation causes many early failures: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
The most common problems we see are:
- Brick movement joints where the sealant has split
- Movement joints filled with mortar instead of sealant
- Sealant pulling away from one side of the joint
- Failed sealant between panels on a façade
Dagenham is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- Whether VAT is included
- Which colour the sealant will be
- How much experience the applicator has
- When the joint can take water or movement
Dagenham: your questions answered
Is parking an issue for external mastic in Dagenham?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Can you do external mastic in Dagenham?
Yes. Our work covers London and the South East, and Dagenham is part of that. Just ring 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
Are you insured?
Yes, we’re fully insured.
What is backing rod for?
Backing rod controls the sealant depth and keeps it off the back of the joint. That way it bonds to the two sides only and can stretch.
Will there be a smell?
There can be a smell while the sealant cures, but it fades. Opening a window helps.
Can you work on commercial sites?
Yes, regularly. We can plan bigger jobs in stages.
What do you put in the joint?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference.
Do you remove the old sealant?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Dagenham buildings and the weather
With historic houses such as Rainham Hall (about 2 miles south-east) nearby, there’s older building stock in the area around Dagenham as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
If you live in an older home near St. Peter and St. Paul, old and new materials meet at the roofline and walls, which is where sealant earns its keep. For landlords with property near Dagenham Dock station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Dagenham is about 3 miles south of Romford, in Greater London. Our applicators cover external mastic for homes and businesses in Dagenham. Dagenham is one of 764 towns and villages in Greater London we cover. There’s also a page for London, about 11 miles away.
Jobs for external mastic in RM10, RM9, RM13 and RM7 works the same way as everywhere else we cover. That includes homes and businesses on Exeter Road, Plumtree Close and Rodwell Place and the roads around them. With the B178 close by, Dagenham is simple for us to get to for external mastic. We also cover the places around Dagenham: Becontree (1 mile north-west), Dagenham Green (1 mile south-west), Beam Park (1 mile south), South Hornchurch (1 mile south-east) and Hornchurch Marshes (2 miles south). Further out, we also cover London (11 miles west), City of Westminster (14 miles west), Marylebone (13 miles west), St Pancras (12 miles west), Shoreditch (10 miles west) and Walthamstow (9 miles west).
What’s near Dagenham
Locally, jobs take us to homes and businesses close to Dagenham Park Community School, Beam Valley Country Park and Cross Keys pub and the streets around them. For rail, the closest station is Dagenham Dock station, about 1.2 miles south-west. Nearby you will also find Rush Green Hospital (1.5 miles north-east) and The Brewery (2.5 miles north). The countryside around Dagenham includes Dagenham Village Churchyard.