Greater London · England
Rayners Lane External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Rayners Lane. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old sealant gone brittle and cracked
- Gaps where render, brick and frames meet
- Movement joints with cracked, split or missing sealant
External mastic for homes and businesses in Rayners Lane
A movement joint is a deliberate break that lets a wall expand and contract. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. Common call-outs are for weeds or debris growing in open joints and joints pointed up with cement by mistake, on concrete & block, façade panels and copings & trims.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In Rayners Lane, joints up high may need ladders or other access, which is worth talking through when you book.
Whatever the size of the job, it’s backed by our 12-month guarantee in Rayners Lane and across Greater London.
- Location
- Rayners Lane (HA2, HA5, HA4)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the cost of external mastic
You’ll get a clear quote before we start. It’s based on:
- The type of sealant required
- Whether old sealant or filler has to be cut out
- When we can work, for business premises
- How many rooms, windows or areas are involved
The cost reflects the work involved, not a rough estimate. That’s why we ask a few questions first.
What to tell us for a quote
To make quoting easier, please include:
- Where the property is
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that’s easy
- Roughly how big the job is
We quote each job on its own. Simply ring 0345 464 0079 or email us and describe the job, and pictures are welcome.
Can I do it myself?
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
Towns and villages near Rayners Lane
Other services in Rayners Lane
Questions from Rayners Lane
Can parking be tricky for a visit in Rayners Lane?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Can you help a landlord with a rental near Northolt Park station?
Yes, we work for letting agents and landlords. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear price.
What should I tell you?
Tell us what needs doing and where, plus pictures if you have them. If we need more, we will ask.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back, so the joint can move.
What’s an expansion joint in brickwork?
It’s a deliberate gap that lets the wall expand and contract without cracking. It’s sealed with a flexible sealant, not mortar.
Is the work guaranteed?
Yes. Each job is guaranteed for twelve months, large or small.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us, and we’re fully insured.
Can you quote for more than one area?
Yes, and it often makes sense. Doing several areas at once is usually more efficient.
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Have failed joints looked at early
- Clear growth from the base of walls and joints
- Ask before painting over external sealant
- Wash walls gently around the sealant
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Small splits are the time to act. At that stage it’s a simple cut out and reseal before water has had years to get in.
What we are called out for in Rayners Lane
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it can’t stretch and tears as soon as the joint widens.
If you can see any of these, it’s time to have the joints looked at:
- Cracked joints where brick meets render or frames
- Joints where the bead has come unstuck
- Joints pointed up with cement by mistake
- Moss and dirt in joints with no sealant left
For landlords with property near Northolt Park station, split movement joints are easy to miss on a rental until damp shows inside.
Before you book anyone
- What insurance they hold
- How the surfaces are prepared before sealing
- Who does the work, and how experienced they are
- Whether they seal over old material or remove it
The process
There isn’t much for you to do on the day. Show us the job and we will take it from there. The job generally takes a few hours for a handful of joints, longer for a whole elevation from start to finish. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Rayners Lane. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Mention any tricky access
- Let us know about earlier repairs to the joints
Getting a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
Related advice
What external mastic looks like in Rayners Lane
Historic houses like Headstone Manor (about 1.7 miles north-east) are a reminder that the area around Rayners Lane 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. 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.
Rayners Lane is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. In the older streets around St. Andrew’s Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Rayners Lane is about 1 mile west of Harrow, in Greater London. Rayners Lane gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Rayners Lane is one of 764 places in Greater London where we work for external mastic. We also work in London, around 13 miles away.
Every address in HA2, HA5 and HA4 is covered for external mastic, from the main roads to the quietest streets. Whether your property is on Kings Road, The Avenue and Torbay Road or a nearby road, our applicators can take on the job. Other places close to Rayners Lane include Roxbourne (1 mile west), North Harrow (1 mile north-east), Harrow (1 mile east), Eastcote (1 mile north-west) and South Harrow (1 mile south-east). Larger places within reach include London (13 miles south-east), City of Westminster (10 miles south-east), Marylebone (10 miles east), Kensington (9 miles south-east), St Pancras (11 miles east) and Shoreditch (13 miles east).
What’s near Rayners Lane
Typical jobs here are in homes near Eastcote House Gardens, Pinner High School and Heathfield School and the streets around them. Rayners Lane’s nearest station is Northolt Park station, roughly 1.2 miles south-east. Other landmarks nearby include Clementine Churchill Hospital (1.9 miles east) and St. George's Shopping Centre (1.6 miles east). Open spaces near Rayners Lane include Northala Fields and Islip Manor Meadows.
How the job changes by surface
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. We size the backing rod to the gap.
Brickwork movement joints
Brick movement joints are often mistaken for a missing mortar line. Where one has been mortared, we cut it out and reseal it with sealant if the joint can be cleared.
Why deal with it now?
Mortar or ordinary filler might look like a quick way to close an open joint, but it locks the joint solid. The wall then cracks somewhere else. The correct repair is a flexible sealant with the right backing. In a flat in Rayners Lane, 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.
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
Why book with us
- White, clear, grey or coloured to suit, where the product allows
- Quality sealants from Arbo and Everbuild
- We’re fully insured
- 4.9 on Google from 180+ five-star reviews
Read what affects the cost or customer reviews.