Greater London · England
Maryland External Mastic
Our applicators work in Maryland on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- Water getting into walls through failed joints
- Rigid filler in a joint that should flex
- Cracked joints where brick meets render or frames
How we handle external mastic in Maryland
We are ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Some surfaces need a primer before sealing, and we don’t skip that step. If you are dealing with old sealant gone brittle and cracked and rain getting behind render or cladding at a joint, we can put it right.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Maryland, tell us how high the joints are and how to reach the back of the building.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Maryland (E15, E20, E7)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
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.
Places near Maryland
Also in Maryland
Leave it or put it right?
Sealing over the top of old mastic doesn’t hold for long. The new layer cannot bond properly to old, weathered material, so we always take the old sealant out. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler for homes in Maryland.
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, phone 0345 464 0079 or email us for an honest opinion and a quote.
Why Maryland clients choose us
- Fully insured
- A 12-month guarantee on all work
- 180+ five-star Google reviews
- White, clear, grey or another colour, product permitting
The process
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. In Maryland, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Keep children and pets away from the work area
- Mention any tricky access
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
Need a quote? Please call 0345 464 0079 or drop us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
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What affects the quote in Maryland
Some jobs are bigger than they look, and some smaller. The main factors:
- Mould in or behind the old joints
- How much old sealant there is and how hard it is to remove
- How many areas need sealing
- The product the joint needs
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Ask us for a quote and we’ll go through it with you.
What we need to know
When you call or email, these details help:
- What’s wrong with the joints now
- A few photos by email, if you can
- If it’s domestic, commercial or a hotel
- Any previous sealing or DIY work
Every job is quoted individually. Just phone 0345 464 0079 or send us an email with the details and send photos if you have them.
Questions from Maryland
Is parking an issue for external mastic in Maryland?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Do you cover Maryland for external mastic?
Yes. Our work covers London and the South East, and Maryland is part of that. You can phone 0345 464 0079 or drop us an email and let us know what needs doing, and we will give you a clear quote.
Can tenants book the work?
We’re happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
Do you seal joints where cladding meets other materials?
Yes. Different materials move at different rates, so the joint between them must be flexible. The sealant is matched to both sides.
How long before the joint can be used?
Different products cure at different speeds, so follow the cure time we give you.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Do you work for hotels and businesses?
Yes. We can plan bigger jobs in stages.
Is there any odour?
Some sealants have a smell while they cure, but it fades. Opening a window helps.
What we’re called out for in Maryland
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Any of these means the joints need attention:
- Hard, crazed mastic that has stopped moving
- Failed sealant between panels on a façade
- Cracked joints where brick meets render or frames
- Movement joints filled with mortar instead of sealant
Letting a property close to Stratford (London) station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Before you book anyone
- What the quote includes, VAT included or not
- Whether the sealant suits the joint
- How much experience the applicator has
- What happens if the job turns out different
What the job involves on each surface
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.
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. Where one has been mortared, we cut it out and reseal it with sealant where it can be done safely.
Maryland buildings and the weather
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. 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.
As a London address, Maryland can be tricky for parking: let us know about parking bays, permits or a driveway. If you live in an older home near Church of St John the Evangelist, an extension built onto an older house moves differently, and the joint between them takes the strain.
Maryland is about 3 miles south of Walthamstow, in Greater London. Homes, rented property, offices and hotels in Maryland is covered for external mastic. Every job comes with our one-year guarantee. Maryland is one of 764 towns and villages in Greater London we cover.
Postcode districts we cover here for external mastic: E15, E20 and E7. If you need external mastic at a property on Cam Road, Ward Road and Wise Road or a nearby road, we can help. If you are just outside Maryland, we cover Stratford (1 mile west), East Village (1 mile north-west), Temple Mills (1 mile north-west), West Ham (1 mile south-east) and Holloway Down (1 mile north). Within a short drive, we also cover London (5 miles south-west), City of Westminster (7 miles west), Marylebone (6 miles west), Kensington (9 miles west), St Pancras (5 miles west) and Shoreditch (3 miles west).
Landmarks near Maryland
Locally, jobs take us to homes and businesses close to Sarah Bonnell School, West Ham Park and Carpenters Primary School. Maryland has its own railway station: Stratford (London) station. Nearby you will also find Passmore Edwards Museum (0.5 miles east) and Tower of London (4 miles south-west). Not far away are Old Ford Island and Hollow Pond.
Honest limits
A few problems are outside what sealant work can do:
- Cracks in the bricks or render themselves, away from the joints
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Failed render or damaged cladding panels
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly before booking.
What we seal
- Concrete & block
- Façade panels
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Joints between brick and frames