Greater London · England
External & façade joints in Lee, Greater London
We cover Lee for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Panel joints letting water in
- Weathered mastic that no longer stretches
- Brick movement joints where the sealant has split
What affects the quote in Lee
Some jobs are bigger than they look, and some smaller. The main factors:
- The size of the job
- Mould in or behind the old joints
- When we can work, for business premises
- Which sealant suits the joint
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Whether it’s a home or a business
- Roughly how big the job is
- What’s wrong with the joints now
- The address or postcode of the job
For a quote, call 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.
External mastic for homes and businesses in Lee
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. The colour is chosen to suit the brick or render so the line blends in. If you have brick movement joints where the sealant has split and gaps where render, brick and frames meet, we can help, on joints between brick and frames, façade panels and render & cladding joints alike.
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 Lee, it’s worth checking who is responsible for the outside before booking.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Lee (SE12, SE13, SE3)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What external mastic looks like in Lee
In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts. 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.
Schools such as Brindishe Lee School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. As a London address, Lee can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Lee is about 2 miles south of Greenwich, in Greater London. Across the SE12 area, we cover external mastic for homes and businesses. Our area takes in 764 places across Greater London, from the larger towns to small villages. There’s also a page for London, about 6 miles away.
We work across the SE12, SE13 and SE3 postcode area for external mastic and the streets around it. Streets in the area include Old Road, Manor Lane and Mallet Road. Close by, we work in Hither Green (1 mile west), Horn Park (1 mile south-east), Lewisham (1 mile north-west), Ladywell (1 mile west) and Blackheath (1 mile north). Further out, we also cover London (6 miles north-west), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (10 miles west), St Pancras (7 miles north-west) and Shoreditch (6 miles north-west).
Local landmarks in Lee
Typical jobs here are in homes near Manor House Gardens, Trinity Church of England School and International Academy of Greenwich and the streets around them. Lee has its own railway station: Lee station. Other landmarks nearby include Lewisham Shopping Centre (1.1 miles north-west) and Prefab Museum (1.3 miles south). Green spaces nearby include Summer Hill and Birdbrook Road Nature Reserve.
Other services in Lee
What we do, step by step
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes a few hours for a handful of joints, longer for a whole elevation, depending on the amount of work. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- 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.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
How to prepare
- On commercial sites, let us know about site rules
- Mention any tricky access
- Try not to wet indoor joints just before the visit
Getting a quote
There’s no standard price list. Instead, we send you a clear quote for your job. To arrange one, ring 0345 464 0079 or send us an email.
Read more
Different surfaces, different methods
Cladding and façade panels
If the façade has a specified sealant, that’s what we use or an approved alternative. Send us any details you have about the façade.
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. The movement joint takes that up, so its sealant has to stay flexible.
Signs you need external mastic in Lee
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
Signs it’s time to call us include:
- Water getting into walls through failed joints
- Weeds or debris growing in open joints
- Weathered mastic that no longer stretches
- Leaking joints around cladding and façade panels
In the older streets around Church of the Good Shepherd, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Questions to ask before booking
- Is VAT in the price?
- Which colour the sealant will be
- How long the guarantee is
- Which sealant they’ll use, and why
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
Leave it or put it right?
An open joint keeps letting water into the wall with every downpour. Wet masonry is more easily damaged by frost, so the problem grows beyond the joint itself. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we’ll talk you through it.
Why choose Mr Mastic in Lee
- We agree the colour with you first
- Colour picked to suit the job
- Tidy, careful work
- Arbo and Everbuild products
Read our cost guide or our reviews.
What we cannot put right
In fairness, some problems need a different trade:
- Adding movement joints to masonry that has none
- Render that is blown, hollow or coming away
- Rising or penetrating damp from elsewhere in the wall
If in doubt, ring 0345 464 0079 or drop us an email and we’ll say what we think before you book.
Joints and surfaces we work on
- Brickwork movement joints
- Render & cladding joints
- Copings & trims
- Façade panels
- Joints between brick and frames
- Concrete & block
Lee questions
I let a flat near Lee station. Can you help?
Yes, we work for landlords and letting agents. Just ring 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear price.
Do you cover Lee for external mastic?
Yes, Lee is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing, and we’ll send you a clear quote.
Do I have to be there?
We need access to the joints, so we will agree that with you when we book. For inside work, that normally means someone being in.
What is backing rod for?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back so the bead can stretch.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
How long should I leave it?
Different products cure at different speeds, so please follow the time we give you when we finish.
Are you fully insured?
Yes. Full insurance covers our work.