Greater London · England
Sipson External Mastic
External mastic for Sipson and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Brick movement joints where the sealant has split
- Weathered mastic that no longer stretches
- Sealant pulling away from one side of the joint
What we do, step by step
When we arrive, we look over the joints with you first, so there are no surprises. Surfaces next to the work are protected before any work begins. Most jobs take a few hours to a few days, depending on the length of joint and the access. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Sipson. It helps if you can point us to a visitor permit or a bay close to the door.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Mention any leaks or damp you’ve noticed
- Plan for the work area to be out of bounds to pets and children
- Try not to wet indoor joints just before the visit
How to get a quote
If you’re in Sipson and need external mastic, phone 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before any work starts.
Related advice
External mastic for homes and businesses in Sipson
We are ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Some surfaces need a primer before sealing, and we do not skip that step. If you have weathered mastic that no longer stretches and gaps where render, brick and frames meet, we can put it right.
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 Sipson, it’s worth checking who is responsible for the outside before booking.
Big or small, it’s backed by our one-year guarantee.
- Where
- Sipson (UB7, UB3)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Towns and villages near Sipson
What else we do in Sipson
External mastic in Sipson: local notes
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Osterley House (about 4.3 miles east) nearby, there’s older building stock in the area around Sipson as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
If you live in an older home near Christ Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. Rented homes near West Drayton station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Sipson is about 1 mile south-east of West Drayton, in Greater London. Our applicators cover external mastic for homeowners, landlords and businesses in Sipson and the surrounding area, as part of our work across Greater London. Our Greater London coverage runs to 764 places, and Sipson is one of them. Our London page covers work nearby, about 15 miles away.
We cover every part of the UB7 and UB3 postcode area for external mastic and the streets around it. External mastic is available to properties on East Road, Sipson Lane and Sipson Road. If you are just outside Sipson, we cover Harlington (1 mile south-east), Harmondsworth (1 mile south-west), Heathrow (2 miles south), Cranford (2 miles south-east) and Longford (2 miles south-west). Further out, we also cover London (15 miles east), City of Westminster (13 miles east), Marylebone (13 miles east), Kensington (11 miles east), St Pancras (14 miles east) and Hampstead (12 miles east).
Around Sipson
Around Sipson, our work takes us to homes and buildings near Lake Farm Country Park, Harlington Community School and The Plough pub and the streets around them. The nearest railway station is West Drayton station, roughly 1.4 miles north-west of the centre. Other landmarks nearby include The Chimes (3.7 miles north) and Harlington (under half a mile south). The countryside around Sipson includes Northala Fields and Crane Meadows.
Honest limits
To be straight with you, some problems need a different trade:
- Movement that is more than a sealant joint can take
- Rising or penetrating damp from elsewhere in the wall
- Cracked brickwork or render that needs a builder or plasterer
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly before booking.
Joints and surfaces we work on
- Concrete & block
- Render & cladding joints
- Façade panels
- Copings & trims
- Brickwork movement joints
- Joints between brick and frames
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
What the job involves on each surface
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. We reseal them with a low-modulus sealant over backing rod in a colour to suit the brick.
Render joints
Rendered walls have joints at beads, openings and changes of material. They’re resealed in a sealant that suits the render.
What we’re called out for in Sipson
A lot of failed joints come down to preparation: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The sealant never bonds properly.
Signs it’s time to call us include:
- Damp patches traced to an open external joint
- Old sealant gone brittle and cracked
- Joints with sealant missing in places
- Sealant pulling away from one side of the joint
Sipson is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Before you book anyone
- How the surfaces are prepared before sealing
- What happens if the job turns out different
- Whether the sealant suits the joint
- How long to leave it before use
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Tell anyone working on the walls about the movement joints
- Clear growth from the base of walls and joints
- Check the sealant is paintable before painting near it
- Look over the joints every year, ideally after winter
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Leave a failed movement joint and water keeps getting into the wall. Over time it can mean damp inside, stained render or frost-damaged brick, all bigger jobs than a reseal.
Questions from Sipson
Do you work for landlords with property near West Drayton station?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Is Sipson in your area for external mastic?
Yes, Sipson is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job.
Do you guarantee your work?
Yes, always. There’s a 12-month guarantee on every job.
Is there any odour?
It depends on the product. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Can I do it myself?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
Can you work on commercial sites?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
What is a movement joint?
Walls move with heat, cold and moisture, so long walls have planned gaps to take that movement. It’s closed with backing rod and a flexible sealant.
Are you an approved applicator?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
For landlords and businesses
If you manage several properties in or around Sipson, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
We work for landlords and agents as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.