Greater London · England
Hill End External Mastic
External mastic across Hill End and nearby, with every bit of old sealant taken out first.
- Joints pointed up with cement by mistake
- Sealant pulling away from one side of the joint
- Moss and dirt in joints with no sealant left
How we handle external mastic in Hill End
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible exterior sealant takes up that movement where mortar or filler would crack. If you have rain getting behind render or cladding at a joint and sealant that has lost its bond to the brick or render, we can put it right, on render & cladding joints, joints between brick and frames and façade panels alike. Looking for a professional mastic man in Hill End? That’s us, fully insured and ARBOMaster approved.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so a leaking gutter joint or failed wall joint can affect more than one home. For a flat in Hill End, check the lease for who looks after the outside.
Our work is backed for twelve months, in Hill End and everywhere else we cover.
- Place
- Hill End (UB9)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear quote up front
- Telephone
- 07833 053749
- Page updated
- 26 October 2026
Why it’s worth doing now in Hill End
Resealing a run of joints in one go is normally better than patching one at a time. They’ve weathered the same way and it means sorting access once. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
What it costs depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start.
Why Hill End customers choose us
- We’re fully insured
- Anti-fungal sanitary silicone in wet areas
- An ARBOMaster approved applicator
- Over 20 years’ experience
Take a look at how sealant jobs are priced and customer reviews.
Towns and villages near Hill End
Also in Hill End
When something else is needed
It helps to know what we can’t do too:
- Damp that isn’t coming from the joint
- Adding movement joints to masonry that has none
- Loose or hollow render, which needs re-rendering
If you’re not sure, just call 07833 053749 or drop us an email and we’ll give you a straight answer.
Surfaces we seal
- Brickwork movement joints
- Façade panels
- Concrete & block
- Render & cladding joints
- Joints between brick and frames
- Copings & trims
What affects the quote in Hill End
Some jobs are bigger than they look, and some smaller. The main factors:
- The old material and how stubborn it is
- Working hours on commercial sites
- How many rooms, windows or areas are involved
- How much there is to do
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
Asking for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Photos by email, if that’s easy
- If someone has resealed it before
- The rough size of the job
- The address or postcode of the job
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we’ll talk you through the work.
External mastic in Hill End: local notes
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts.
Managing a site like Harefield Infant School? Then larger buildings have long runs of movement joint that eventually need resealing. If you live in an older home near Harefield Baptist Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. As a London address, Hill End can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Hill End is about 2 miles south-west of Rickmansworth, in Greater London. Jobs in Hill End get the same care as everywhere else we work: old sealant removed completely, careful preparation and a 12-month guarantee. Hill End is one of 786 towns and villages in Greater London where we work.
All of UB9 is covered for external mastic. External mastic is available to properties on Hill End Road, Plough Lane and Springwell Lane. Neighbouring places we cover for external mastic include Harefield (1 mile south), Woodcock Hill (1 mile north-east), Batchworth (2 miles north-east), Mill End (2 miles north) and Batchworth Heath (2 miles east). We also work in nearby towns such as Kensington (14 miles south-east), Hampstead (14 miles east), Ruislip (4 miles south-east), Ealing (10 miles south-east), Hayes (7 miles south) and Finchley (13 miles east).
What’s near Hill End
Locally, jobs take us to homes and businesses close to The Green, The Harefield Academy and The King's Arms Public House and the streets around them. The nearest railway station is Rickmansworth station, roughly 1.9 miles north. Well-known places in the area include Harefield Hospital (0.5 miles south) and Chiltern Open Air Museum (2.9 miles north-west). The countryside around Hill End includes Northmoor Hill Wood and Tumbling Bay.
How the job changes by surface
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. We reseal them with a low-modulus sealant over backing rod coloured to suit the wall.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Keeping the joints in good condition
Aftercare is simple:
- Wash walls gently around the sealant
- Have failed joints looked at early
- Ask before painting over external sealant
- Show decorators and builders where the movement joints are
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
How the visit works
Before we leave, we go over the finished joints with you and explain the cure time. The visit itself usually takes anything from a few hours to several days, depending on the building, depending on how much there is to do. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. 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.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Mention if the joints have been sealed before
- Mention any parking rules near the property
Getting a quote
Need a quote? Please phone 07833 053749 or drop us an email with a few details. You will know what we plan to do, and what it will cost, before any work begins.
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Your questions about external mastic in Hill End
Can you help a landlord with a rental near Rickmansworth station?
Yes, landlords and agents are among the people we work for. Just phone 07833 053749 or email us with the address and what needs doing, and we’ll give you a clear price.
Is parking an issue for external mastic in Hill End?
Parking in Hill End, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Are you ARBOMaster approved?
Yes. We are an ARBOMaster approved applicator.
What should I tell you?
Only a few details: where it is, what you’ve noticed and how we reach it. Then call 07833 053749 or drop us an email.
Do you seal joints where cladding meets other materials?
Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. The sealant is matched to both sides.
How often do external joints need resealing?
That varies with the weather the wall faces, how much it moves and the sealant used. Treat it as a maintenance item and look at it yearly and reseal when it splits.
Do you work in Hill End?
Yes. We work in Hill End, as part of our work across South East England, London and Scotland. To book, call 07833 053749 or drop us an email.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
DIY sealant or a professional job?
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so tell us about it when you ask for a quote.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.