Greater London · England
Dalston External Mastic
External mastic for Dalston, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Weeds or debris growing in open joints
- Movement joints filled with mortar instead of sealant
- Old sealant gone brittle and cracked
Do you need external mastic in Dalston?
Joints sealed without backing rod, or far too deep, rarely last. Sealant bonded to three sides has nowhere to go and tears as soon as the joint widens.
It’s worth asking for a quote if you see:
- Failed sealant between panels on a façade
- Hard, crazed mastic that has stopped moving
- Rigid filler in a joint that should flex
- Rain getting behind render or cladding at a joint
Letting a property close to Dalston Junction station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before you book
- Whether they seal over old material or remove it
- When the joint can take water or movement
- Is VAT in the price?
- How the joint is cleaned and prepared
External mastic in Dalston
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, so it bonds to the two sides only and can stretch. We work on concrete & block, copings & trims and façade panels, and common reasons people get in touch are hard, crazed mastic that has stopped moving and joints where the bead has come unstuck.
Modern London flats rely on sealed movement joints and cladding joints. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
The work is covered for a year after we finish. If anything is not right with it, phone 0345 464 0079 or send us an email.
- Where
- Dalston (E8, N1, N16)
- Wider area
- Greater London
- Cover
- One year on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
When something else is needed
Some problems need a builder, plumber or other trade rather than us:
- Damp that is not coming from the joint
- Render that is blown, hollow or coming away
- Cutting new joints into brickwork, which is building work rather than sealant work
Not sure which it is? You can phone 0345 464 0079 or email us and we will tell you honestly.
Where we work in Dalston
- Façade panels
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
Towns and villages near Dalston
Other services in Dalston
DIY sealant or a professional job?
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Your questions about external mastic in Dalston
I let a flat near Dalston Junction station. Can you help?
Yes, we work for landlords and letting agents. Just call 0345 464 0079 or email us and tell us about the property, and we will give you a clear price.
Is parking an issue for external mastic in Dalston?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Do I have to be there?
That depends on where the joints are. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose. We will reseal it with a flexible sealant.
Is there a guarantee?
Yes, for a year. If anything isn’t right with the work within the year, let us know and we will sort it.
Are you insured?
Yes. We’re fully insured.
What information do you need?
Where the job is, what the problem is and roughly how big it is. Photos by email help too.
Will you leave a mess?
We keep the work tidy. We protect what’s around the joints.
Outside joints around Dalston
With historic houses such as Sutton House (about 0.9 miles east) nearby, there’s older building stock in the area around Dalston 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.
Schools such as Holy Trinity Church of England Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Homes close to Holy Trinity Church include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Dalston is about 1 mile north-east of Hoxton, in Greater London. For external mastic in and around Dalston, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Greater London. Our area takes in 764 places across Greater London, large and small.
Here we cover the E8, N1 and N16 postcode area for external mastic. We cover properties on Glebe Road, Forest Road and Boleyn Road and the roads around them. Main roads around Dalston include the A107 and A1207, so getting to you is simple. We also cover the places around Dalston: Kingsland (1 mile west), De Beauvoir Town (1 mile west), Hackney Central (1 mile east), London Fields (1 mile south-east) and Shacklewell (1 mile north). Larger places within reach include London (3 miles south), City of Westminster (4 miles south-west), Marylebone (4 miles south-west), Kensington (6 miles south-west), Walthamstow (4 miles north-east) and Hampstead (5 miles west).
What’s near Dalston
Typical jobs here are in homes near Kingsland Secondary School, The Petchey Academy and The Duke Of Richmond Public House. Also close by are Haggerston Park (0.8 miles south) and Bishopsgate Institute Special Collections and Archives (1.9 miles south). There’s a railway station in Dalston itself: Dalston Junction station. A little further out are Clowns Gallery-Museum (under half a mile west) and Montfichet's Tower (2.6 miles south-west). The countryside around Dalston includes Gillespie Park and Ludgate Hill.
Why act early in Dalston
Pointing a movement joint with mortar might seem a neat fix, but it locks the joint solid. The movement then cracks the brickwork or render nearby. A flexible sealant over backing rod is what the joint needs. In a flat in Dalston, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you are unsure, ring 0345 464 0079 or drop us an email and we’ll give you an honest view and a quote.
Why book with us
- Colour agreed with you before any work starts
- We leave the area clean and tidy
- Arbo and Everbuild products
- ARBOMaster approved applicator
Take a look at what affects the cost or what customers say.
How the job changes by surface
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. Each is resealed with a weatherproof, flexible sealant.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
What happens on the day
The work is kept neat and contained to the joints we’re treating, so you can get on with your day. Expect the work to take anything from a few hours to several days, depending on the building, and we explain the cure time before we leave. In Dalston, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We start by walking round the building and agreeing the joints and the access.
- 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.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
- Move anything stored near the joints
- Try not to wet indoor joints just before the visit
Ask for a quote
Asking for a quote is easy: let us know the job and the location and its rough size. A few pictures by email make the job easier to understand, and we’ll come back to you with a quote.
Related advice
Quotes for external mastic in Dalston
You’ll get a clear quote before work begins. It takes into account:
- Whether the work is at height
- How much there is to do
- The product the joint needs
- Whether old sealant or filler has to be cut out
Combining jobs into one visit is usually more efficient than separate visits, so tell us about everything that needs sealing. We will send you a clear quote for the lot.
Helping us quote
When you call or email, these details help:
- If someone has resealed it before
- Photos by email, if that is easy
- Access, such as stairs, a lift or height
- If it’s domestic, commercial or a hotel
For a quick quote, get us on the phone, or email us if that is easier. Describe what needs sealing and we’ll explain what’s involved and send you a clear quote.