Greater London · England
External Mastic in Crofton Park
Our applicators work in Crofton Park on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Weeds or debris growing in open joints
- Joints pointed up with cement by mistake
- Damp patches traced to an open external joint
Questions from Crofton Park
Is parking a problem for a job in Crofton Park?
Parking in Crofton Park, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Can you help a landlord with a rental near Crofton Park station?
Yes, we work for landlords and agents. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
Can you seal joints between render and window frames?
Yes. Different materials move at different rates, so the joint between them must be flexible. We choose one that suits both surfaces.
Can you match the colour of my brickwork?
We aim for a joint that suits the wall rather than one that jumps out. Colour is agreed with you before we begin from the range available.
Is it messy?
No. The area is protected while we work and cleaned up afterwards.
Do you work for hotels and businesses?
Yes. Commercial and hotel work is a large part of what we do. We can talk about working times when we quote.
Can new sealant go over the old?
No. Fresh sealant does not stick to old sealant, and it traps any mould or water underneath. It all has to come out first.
How often do external joints need resealing?
It depends on the exposure, the movement and the product. Sealant is a maintenance item, so check the joints once a year.
External mastic in Crofton Park, done properly
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. We are often asked to deal with weeds or debris growing in open joints and damp patches traced to an open external joint, across brickwork movement joints, render & cladding joints and copings & trims.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
All our work comes with our one-year guarantee, wherever you are in Greater London.
- Where
- Crofton Park (SE4, SE6, SE23)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Signs you need external mastic in Crofton Park
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint cannot move, so the wall cracks somewhere else instead.
The problems people generally mention when they call include:
- Hard, crazed mastic that has stopped moving
- Sealant that has lost its bond to the brick or render
- Movement joints with cracked, split or missing sealant
- Weeds or debris growing in open joints
As a London address, Crofton Park can be tricky for parking: let us know about parking bays, permits or a driveway.
What to look for in a quote
- Whether all the old sealant comes out first
- How long to leave it before use
- How hidden problems are handled
- What insurance they hold
Surface by surface
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. Their movement joints are sealed over backing rod with a flexible sealant.
Why it’s worth doing now in Crofton Park
Sealing over the top of old mastic doesn’t hold for long. The new layer can’t bond properly to old, weathered material, so the old joint is cut out fully first. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Crofton Park, the repair is bigger than a sealant job.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all make a difference.
Why Crofton Park clients choose us
- Tidy, careful work
- We are fully insured
- Old sealant always removed completely
- 12-month guarantee on every job
Take a look at what affects the cost or what customers say.
How we quote for external mastic
Jobs vary more than people expect. The main factors:
- When we can work, for business premises
- How much there is to do
- Access and height
- Any mould that needs treating
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will go through it with you.
Helping us quote
Before you ask for a quote, have a think about:
- Any previous sealing or DIY work
- What’s wrong with the joints now
- Where the job is, and your postcode
- The rough size of the job
Need a quote? Please phone 0345 464 0079 or email us and tell us about the job. We will explain what we’d do and send you a clear quote before work begins.
Work for landlords, hotels and businesses
Letting agents and landlords in Crofton Park can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will quote.
Towns and villages near Crofton Park
What else we do in Crofton Park
The process
We work through the job in order: protect, prepare, seal, tidy. Typically it takes anything from a few hours to several days, depending on the building. In Crofton Park, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Mention any parking rules near the property
- Tell us about any water getting in
- Keep pets and children clear of the area while we work
Get a quote
We quote each job on its own, so the first step is telling us about yours. Just call 0345 464 0079 or send us an email with the details.
Advice
External mastic in Crofton Park: local notes
Historic houses like Queen's House (about 2.4 miles north-east) are a reminder that the area around Crofton Park has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Letting a property close to Crofton Park station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies. If you look after a building such as Stillness Infant School, larger buildings have long runs of movement joint that eventually need resealing.
Crofton Park is about 1 mile south of New Cross, in Greater London. We carry out external mastic for homes and businesses in Crofton Park and the surrounding area. Crofton Park is one of 764 places in Greater London where we work.
Every address in SE4, SE6 and SE23 is covered for external mastic. External mastic is available to properties on Ivy Road, Nash Road and Lindal Road. If you are just outside Crofton Park, we cover Brockley (1 mile north-west), Ladywell (1 mile east), Honor Oak (1 mile west), Forest Hill (1 mile south-west) and Nunhead (1 mile north-west). Further out, we also cover London (4 miles north-west), City of Westminster (7 miles north-west), Marylebone (7 miles north-west), Kensington (8 miles north-west), St Pancras (6 miles north-west) and Shoreditch (5 miles north).
What’s near Crofton Park
Typical jobs here are in homes near Blythe Hill Tavern, Prendergast Ladywell School and Blythe Hill Fields. There’s a railway station in Crofton Park itself: Crofton Park station. Well-known places in the area include University Hospital Lewisham (0.7 miles east) and Horniman Museum and Gardens (1.4 miles south-west). The countryside around Crofton Park includes One Tree Hill and Knight's Hill.
Looking after it afterwards
Looking after new joints is easy, and it makes a real difference:
- Make sure movement joints aren’t pointed over
- Have failed joints looked at early
- Walk round the building once a year and look at the joints
- Do not let climbing plants root in the sealant
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
An open movement joint lets rain into the wall every time it pours. Over time it can mean damp inside, stained render or frost-damaged brick.