Greater London · England
External Mastic in Shortlands
Sealing brickwork movement joints, render, cladding and façade joints in Shortlands, with a one-year guarantee on every job. Ask us for a quote.
- Weathered mastic that no longer stretches
- Plants rooting in failed movement joints
- Sealant pulling away from one side of the joint
Different surfaces, different methods
Joints between dissimilar materials
Each side of the joint may need its own preparation. We prepare both faces so the sealant bonds properly.
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.
External mastic in Shortlands
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing, and we do not skip that step. If you are dealing with weeds or debris growing in open joints and sealant that has lost its bond to the brick or render, we can help.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall, and both kinds of building are found across London.
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
- Shortlands (BR2, BR1, BR3)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
Good habits help new joints last longer. A few tips:
- Make sure movement joints aren’t pointed over
- Leave the joints unpainted unless we have said otherwise
- Show decorators and builders where the movement joints are
- Deal with leaking gutters that soak the joints below
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Act while the splits are small. Then it’s a straightforward cut-out and reseal before water has had years to get in.
Questions from Shortlands
Is Shortlands in your area for external mastic?
Yes, Shortlands is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or drop us an email and let us know what needs doing.
Can you help a landlord with a rental near Shortlands station?
Yes. We work for landlords and agents as well as householders, 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.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint.
Can I add another job to the visit?
Of course. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Do you hold any approvals?
Yes. We are an ARBOMaster approved applicator.
Do you take out the old sealant first?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Do you use backing rod?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only.
How long does external mastic last?
It varies from wall to wall: sunny, exposed elevations and busy joints wear faster. A yearly look will tell you when they need doing. Our work comes with a one-year guarantee.
For landlords and businesses
Housing providers, facilities teams and property managers book us too in Shortlands and across Greater London. We can quote a run of properties together.
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Walls and rooflines in Shortlands
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. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
Rented homes near Shortlands station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets. For site and facilities teams at buildings such as Highfield Infants' School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Shortlands is about 1 mile south-west of Bromley, in Greater London. We provide external mastic to homeowners, landlords and businesses in Shortlands and nearby. 764 places in Greater London are on our list, large and small. There’s also a page for London, roughly 8 miles from Shortlands.
We work across BR2, BR1 and BR3 for external mastic and the streets around it. Whether your property is on Hayes Lane, Stone Road and Hayes Road or a nearby road, we can help. We also cover Eden Park (1 mile south-west), Hayes (2 miles south), Bromley Common (2 miles south-east), West Wickham (2 miles south-west) and Southborough (2 miles east). We also work in nearby towns such as London (8 miles north-west), City of Westminster (10 miles north-west), Marylebone (11 miles north-west), Kensington (11 miles north-west), St Pancras (10 miles north-west) and Shoreditch (10 miles north).
Landmarks near Shortlands
Typical jobs here are in homes near The Richmal Crompton pub, Church House Gardens and Langley Park School for Girls, among other places. Shortlands’s nearest station is Shortlands station, about 0.5 miles north. Well-known places in the area include Bromley Hospital (0.7 miles east) and Bethlem Museum of the Mind (1.6 miles south-east). Green spaces nearby include Summer Hill and Downham Woodland Walk.
DIY sealant or a professional job?
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Signs you need external mastic in Shortlands
A lot of failed joints come down to preparation: dusty or wet faces, no primer where one was needed, or old sealant left in. The new sealant then lets go long before it should.
Signs it’s time to call us include:
- Rigid filler in a joint that should flex
- Plants rooting in failed movement joints
- Failed sealant between panels on a façade
- Rain getting behind render or cladding at a joint
Shortlands is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Before booking anyone
- When the joint can take water or movement
- What product goes in the joint
- Are they insured?
- How hidden problems are handled
Nearby places to Shortlands
More services for Shortlands
How we quote for external mastic
Call for a quick quote. The main things that affect it are:
- How much there is to do
- How much old sealant there is and how hard it is to remove
- The number of rooms or windows
- When we can work, for business premises
The cost reflects the work involved, not guesswork. That is why we ask a few questions first and agree the price before starting.
Asking for a quote
What to tell us when you ask for a quote:
- Access, such as stairs, a lift or height
- The address or postcode of the job
- Whether it’s a home or a business
- Whether it has been sealed before
For external mastic in Shortlands, ring 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and you will get a clear quote before any work starts.
What happens on the day
We work through the job in order: protection first, then preparation, sealing and a tidy-up. Typically it takes anything from a few hours to several days, depending on the building and we leave things clean and tidy. In Shortlands, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Getting ready for the visit
- Tell us about any previous sealing or DIY attempts
- Keep children and pets away from the work area
- Try not to wet indoor joints just before the visit
Ask for a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. Whenever you’re ready, phone 0345 464 0079 or email us.