Greater London · England
External Mastic in Pentonville
External mastic in Pentonville from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Damp patches traced to an open external joint
- Leaking joints around cladding and façade panels
- Cracked joints where brick meets render or frames
External mastic for homes and businesses in Pentonville
For buildings in Pentonville, we reseal external joints of all kinds, from brick movement joints to cladding panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. If you have sealant that has lost its bond to the brick or render and damp patches traced to an open external joint, we can put it right.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In Pentonville, joints up high may need ladders or other access, which is worth talking through when you book.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Pentonville (N1, N1P, EC1V)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible year round.
Joints between dissimilar materials
Each side of the joint may need its own preparation. Both surfaces are cleaned and primed as the product requires.
Pentonville buildings and the weather
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Pentonville is in London, so parking needs planning: let us know about parking bays, permits or a driveway. Schools such as St John Evangelist RC Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Pentonville is about 1 mile north-east of St Pancras, in Greater London. For external mastic in and around Pentonville, it’s easy to get a quote: please phone 0345 464 0079 or email us. We cover Greater London from our Crawley base. Pentonville is one of 764 places in Greater London we cover for external mastic.
Here we cover the N1, N1P and EC1V postcode area for external mastic. Streets in the area include City Road, Noel Road and Dewey Road. With the A1200 close by, Pentonville is easy for our applicators to reach. Other places close to Pentonville include Angel (1 mile south-west), Islington (1 mile north), Clerkenwell (1 mile south), Barnsbury (1 mile north-west) and St Pancras (1 mile south-west). Larger places within reach include City of Westminster (3 miles south-west), Kensington (5 miles south-west), Walthamstow (5 miles north-east), Hampstead (4 miles west), Ruislip (13 miles west) and Brompton (4 miles south-west).
What’s near Pentonville
Around Pentonville, our work takes us to homes and buildings near Islington Green School, The Camden Head Public House and Pilsudski Institute of London. Nearby too are City of London Academy Islington (less than half a mile east) and Barnard Park (less than half a mile west). For rail, the closest station is Essex Road station, roughly 0.5 miles north-east. A little further out are Museum of Funeral History (0.7 miles south-west) and Brunswick Centre (1.2 miles south-west). Open spaces near Pentonville include Ludgate Hill and St. James's Park Lake.
How we quote for external mastic
Every job gets its own quote. These are the things that affect it:
- The number and length of the joints
- Working hours on commercial sites
- Whether the work is at height
- The product the joint needs
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or email us.
Helping us quote
There’s no need for technical detail. It helps if you can tell us:
- If it’s domestic, commercial or a hotel
- Access, such as stairs, a lift or height
- What’s wrong with the joints now
- Pictures of the joints, sent by email
There’s no standard price list, because every job is different. Instead, we send you a clear quote for your job. To arrange one, ring 0345 464 0079 or email us.
Why it’s worth doing now in Pentonville
Water gets in through a failed movement joint and can run behind render or cladding. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Doing several joints on one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Why us?
- Colour picked to suit the job
- We’re fully insured
- Every job guaranteed for a year
- Anti-fungal silicone where joints get wet
How the visit works
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The job generally takes a few hours to a few days, depending on the length of joint and the access, including the tidy-up. 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.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
- Move anything stored near the joints
- Tell us about any previous sealing or DIY attempts
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Related advice
How to look after the new joints
After the cure time, these simple habits help:
- Check external joints each spring
- Keep water from gutters off the wall
- Keep soil, plants and ivy away from the joints
- Keep high-pressure jets off the joints
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
A joint that has stopped moving pushes the movement elsewhere, often as cracks near the joint. Resealing it early helps prevent that.
Places near Pentonville
More services for Pentonville
Common problems we fix in Pentonville
Sunlight, wet weather and frost wear exterior sealant down. Over the years it hardens, cracks on the surface and loses its give, so the joint eventually tears or comes away from one side.
If you can see any of these, it’s time to have the joints looked at:
- Water getting into walls through failed joints
- Joints with sealant missing in places
- Rigid filler in a joint that should flex
- Failed seals between different materials
For an older house near a landmark such as Church of Saint Peter, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Comparing quotes
- How long the guarantee is
- Are they insured?
- How hidden problems are handled
- Is VAT in the price?
Pentonville questions
Can you do external mastic in Pentonville?
Yes. We work across London and the South East, and Pentonville is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job.
Can you help a landlord with a rental near Essex Road station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Where is Mr Mastic based?
Mr Mastic is based in Crawley. Our applicators cover Pentonville.
What colours does the sealant come in?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before we start.
Do you guarantee your work?
Yes, for a year. If there’s a problem with our work in that time, tell us and we will put it right.
How long does the job take?
As a guide, most jobs take a few hours for a handful of joints, longer for a whole elevation. Larger jobs naturally take longer.
Do you use backing rod?
Closed-cell backing rod sets the depth of the sealant and stops it sticking to the back of the joint. Then the sealant bonds to two faces and can move.
Do you work for hotels and businesses?
Yes. Hotels, offices and other businesses use us.
DIY sealant or a professional job?
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.