Greater London · England
St Pancras External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in St Pancras and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old sealant gone brittle and cracked
- Moss and dirt in joints with no sealant left
- Cracked joints where brick meets render or frames
External mastic in St Pancras
External mastic is a job where short cuts show quickly. Overfilled joints, missing backing rod and sealant laid over old sealant rarely last long. We strip the joint back and start again. We work on render & cladding joints, façade panels and copings & trims, and people most often call us about sealant pulling away from one side of the joint and rain getting behind render or cladding at a joint.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in St Pancras, tell us how high the joints are and how to reach the back of the building.
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.
- Where
- St Pancras (NW1W, W1T, N1)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Honest limits
New sealant can’t fix everything, and we’ll tell you before work begins. Sealant will not put right:
- Cracked brickwork or render that needs a builder or plasterer
- Rising or penetrating damp from elsewhere in the wall
- Render that is blown, hollow or coming away
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
Surfaces we seal
- Concrete & block
- Joints between brick and frames
- Render & cladding joints
- Façade panels
- Brickwork movement joints
- Copings & trims
External mastic in St Pancras: local notes
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. With historic houses such as Dr Johnson's House (about 0.9 miles south-east) nearby, there’s older building stock in the area around St Pancras as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
In the older streets around Lumen United Reformed Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. As a London address, St Pancras can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
St Pancras is about 2 miles north-west of London, in Greater London. Every kind of property in St Pancras is covered for external mastic. The work is guaranteed for a year. St Pancras is one of 764 places in Greater London we cover.
Jobs for external mastic in NW1W, W1T and N1 is quoted and booked the same way as anywhere else. If you need external mastic at a property on Shoe Lane, Long Lane and City Road or a nearby road, our applicators can take on the job. St Pancras sits on or near the A4 and A40, so getting to you is simple. Nearby, we also carry out external mastic in Bloomsbury (1 mile south-west), Kings Cross (1 mile north-west), Holborn (1 mile south-east), Clerkenwell (1 mile east) and Angel (1 mile north-east). Larger places within reach include Kensington (4 miles south-west), Walthamstow (6 miles north-east), Hampstead (3 miles north-west), Ruislip (13 miles west), Brompton (3 miles south-west) and Stockwell (4 miles south). St Pancras is one of the larger places we cover in Greater London.
Near you in St Pancras
In St Pancras, that means homes and buildings near Lincoln's Inn Fields, City Academy and Elizabeth Garrett Anderson School. You will also find Pilsudski Institute of London (under half a mile south-west) and Calthorpe Arms Public House (within half a mile south-east). St Pancras’s nearest station is London Kings Cross station, roughly 0.5 miles north-west of the centre. Well-known places in the area include Montfichet's Tower (1.1 miles south-east) and Royal National Throat (under half a mile north). Not far away are Barnsbury Wood and Ludgate Hill.
Landlord and commercial work in St Pancras
In hotels, rooms out of use cost money, so we plan the work room by room. Hotel work is part of what we do, alongside homes and businesses.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
What affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. The main factors:
- Mould in or behind the old joints
- The number and length of the joints
- How easy the joints are to reach
- The product the joint needs
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, along with when we can work on site. Ask us for a quote and we will go through it with you.
Asking for a quote
Before you ask for a quote, have a think about:
- Access, such as stairs, a lift or height
- Pictures of the joints, sent by email
- Any previous sealing or DIY work
- What the problem is, such as mould, gaps, leaks or cracking
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll talk you through the work and send you a clear quote.
St Pancras: your questions answered
Do you work for landlords with property near London Kings Cross station?
Yes. We work for landlords and agents as well as householders. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
Do you cover St Pancras for external mastic?
Yes. Our work covers London and the South East, and St Pancras is part of that. Just call 0345 464 0079 or email us with a few details of the job, and we’ll give you a clear quote.
Will you leave a mess?
No. We work neatly, protect the area around the joints and tidy up afterwards.
What is a movement joint?
Most straight vertical gaps in brickwork are movement joints. It gives the wall room to move and needs a flexible seal, not mortar.
When will the joints need doing again?
It varies from wall to wall: sunny, exposed elevations and busy joints wear faster. Check them each year and reseal when they split or harden. Every job carries our one-year guarantee.
Can I do it myself?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Should I point up the gap in my brickwork?
No. Cement or mortar cannot stretch, so the joint stops doing its job. If it has already been filled, we can generally cut it out and reseal it.
Do you take out the old sealant first?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Can I do it myself?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
How the job changes by surface
Joints between dissimilar materials
Each side of the joint may need its own preparation. We prepare both faces so the sealant bonds properly.
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod coloured to suit the wall.
The process
Before we leave, we go over the finished joints with you and tell you how long to leave it. The visit itself normally takes a few hours for a handful of joints, longer for a whole elevation, depending on the size of the job. In a London area like St Pancras, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- 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.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- For business premises, tell us about site rules or sign-in
- Mention if the joints have been sealed before
Get a quote
Need a quote? Please phone 0345 464 0079 or send us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
When to call us in St Pancras
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and speed up the damage.
Signs it’s time to call us include:
- Panel joints letting water in
- Rain getting behind render or cladding at a joint
- Weathered mastic that no longer stretches
- Cracked joints where brick meets render or frames
If you look after a building such as St George the Martyr Church of England Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Comparing quotes
- Whether all the old sealant comes out first
- Who turns up on the day
- What insurance they hold
- What the cure time is