Greater London · England
Northumberland Park External Mastic
Problem with your movement joints in Northumberland Park? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Plants rooting in failed movement joints
- Brick movement joints where the sealant has split
- Panel joints letting water in
Landlord and commercial work in Northumberland Park
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can go on one quote.
Letting agents and landlords in Northumberland Park can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.
External mastic for homes and businesses in Northumberland Park
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a colour to suit. We work on joints between brick and frames, façade panels and concrete & block, and the jobs we see most are brick movement joints where the sealant has split and plants rooting in failed movement joints.
Modern London flats rely on sealed movement joints and cladding joints. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
All our work is covered by a 12-month guarantee.
- Location
- Northumberland Park (N17, N18)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Questions from Northumberland Park
Can you do external mastic in Northumberland Park?
Yes, Northumberland Park is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
Do you work for landlords with property near Northumberland Park (London) station?
Yes, we work for landlords and agents. Just phone 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear price.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
Why is there a gap in my brick wall?
A vertical gap in a long brick wall is usually a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.
Does someone need to be in?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
Can you reach joints on upper floors?
Each building is different. Tell us the height, the number of joints and what’s below them, and we’ll confirm what access is needed.
How long does the job take?
Most jobs take a few hours for a handful of joints, longer for a whole elevation. We will confirm how long when we quote.
What information do you need?
Just the basics: the address or postcode, what’s wrong and any access issues. Then call 0345 464 0079 or send us an email.
Towns and villages near Northumberland Park
More services for Northumberland Park
When it is not the sealant
Sealant is not the answer to every problem, and we’ll tell you before work begins. It won’t solve:
- Adding movement joints to masonry that has none
- Loose or hollow render, which needs re-rendering
- Cracks in the bricks or render themselves, away from the joints
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
Surfaces we seal
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
- Façade panels
Can I do it myself?
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
Common problems we fix in Northumberland Park
Sunlight, wet weather and frost wear exterior sealant down. In time it goes hard, crazes on the surface and stops stretching, so the next time the wall moves, it splits or pulls away.
These are the problems we’re asked about most:
- Rain getting behind render or cladding at a joint
- Old sealant gone brittle and cracked
- Failed sealant between panels on a façade
- Joints pointed up with cement by mistake
Rented homes near Northumberland Park (London) station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
What your quote should include
- Which sealant they’ll use, and why
- What preparation is included
- How much experience the applicator has
- What the cure time is
The process
On the day, we start by going over the job with you, so you know exactly what we’re doing. We protect the surfaces around the joints before any work begins. Most jobs take a few hours for a handful of joints, longer for a whole elevation. In Northumberland Park, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- First we look over the joints with you, agree which to renew and talk through access.
- 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.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
How to prepare
- Mention any sign-in or site rules at work premises
- Clear items away from the joints we’re working on
- Mention if the joints have been sealed before
Getting a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is. When it suits you, phone 0345 464 0079 or drop us an email.
Related advice
Leave it or put it right?
Resealing a run of joints in one go is usually better than patching one at a time. They’ve weathered the same way and it means sorting access once. In a flat in Northumberland Park, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
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. Call for a quick quote and we will explain what it covers.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- Anti-fungal sanitary silicone in wet areas
- Fully insured
- Old sealant always removed completely
See our cost guide or customer reviews.
Keeping the joints in good condition
A little care helps the new joints last. We recommend:
- Keep soil, plants and ivy away from the joints
- Never let anyone fill a movement joint with mortar
- Check the sealant is paintable before painting near it
- Act on the first splits you see
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
Walls and rooflines in Northumberland Park
In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For an older house near a landmark such as St Paul's Church, older walls, gutters and the joints where extensions meet them need a flexible sealant. As a London address, Northumberland Park can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Northumberland Park is about 1 mile north-east of Tottenham, in Greater London. From the centre of Northumberland Park to the outskirts, external mastic is available for homes and businesses alike. Our Greater London coverage runs to 764 places, and Northumberland Park is one of them. Our London page covers work nearby (7 miles or so).
All of N17 and N18 is covered for external mastic. Local streets include Love Lane, Park Lane and York Road. Neighbouring places we cover for external mastic include Upper Edmonton (1 mile north-west), Edmonton (1 mile north), South Chingford (1 mile east), Picketts Lock (2 miles north-east) and Highams Park (2 miles east). Within a short drive, we also cover London (7 miles south), City of Westminster (7 miles south-west), Marylebone (7 miles south-west), Kensington (10 miles south-west), St Pancras (6 miles south-west) and Shoreditch (6 miles south).
Around Northumberland Park
In Northumberland Park, that means homes and buildings near Duke's Aldridge, No.8 Tottenham pub and London Academy of Excellence Tottenham. There’s a railway station in Northumberland Park itself: Northumberland Park (London) station. Nearby you will also find North Middlesex University Hospital (0.9 miles north-west) and Markfield Beam Engine and Museum (1.6 miles south). Open spaces near Northumberland Park include Pole Hill and Highams Park Lake.