Buckinghamshire · England
External & façade joints in Harefield, Buckinghamshire
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Harefield and across Buckinghamshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Sealant pulling away from one side of the joint
- Joints with sealant missing in places
- Cracked joints where brick meets render or frames
About our external mastic in Harefield
On houses, flats and commercial buildings across Harefield, we reseal joints in brickwork, render, cladding and façade panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. If you have panel joints letting water in and joints with sealant missing in places, we can help, on concrete & block, joints between brick and frames and render & cladding joints alike.
Around Harefield, garages, outbuildings and extensions all add to the joints on the outside of a home. Gutter ends, garage door frames and the joints where an extension meets the house are typical spots for leaks.
Whatever the size of the job, you get the same 12-month guarantee in Harefield and across Buckinghamshire.
- Where
- Harefield (UB9)
- Wider area
- Buckinghamshire
- Cover
- One year on every job
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Leave it or put it right?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. Homes in smaller places like Harefield can face more weather, and failed outside joints let damp into walls. Inside, a split seal lets water into floors and panels just as it would anywhere.
Combining jobs into one visit normally makes better use of the time than several visits. You will get one clear quote for the whole job.
Why book with us
- Sealant colour chosen to suit
- Homes, businesses and hotels
- 12-month guarantee on every job
- ARBOMaster approved applicator
Take a look at our cost guide and what customers say.
How to look after the new joints
After the cure time, these simple habits help:
- Check external joints each spring
- Deal with leaking gutters that soak the joints below
- Keep movement joints as flexible joints, not mortar
- Wash walls gently around the sealant
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They must stay as flexible joints, never rendered or pointed over.
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 which cost more to put right than the joint.
What affects the cost of external mastic
Call for a quick quote. What matters most is:
- Any mould that needs treating
- How many rooms, windows or areas are involved
- How easy the joints are to reach
- The number and length of the joints
What it costs depends on the amount of work, how much old material has to come out and access to the work. We give a clear quote before work begins, so you know where you stand.
Helping us quote
Photos by email are helpful but not essential. Try to tell us:
- The address or postcode of the job
- The problem you’ve noticed
- Whether it has been sealed before
- Roughly how big the job is
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. Whenever you’re ready, phone 0345 464 0079 or send us an email.
DIY versus a professional finish
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Towns and villages near Harefield
Other services in Harefield
FAQs for Harefield
Is Harefield in your area for external mastic?
Yes, Harefield is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or email us with a few details of the job.
Do you work for landlords with property near Denham station?
Yes, we work for letting agents and landlords. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Can I do it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
What do you put in the joint?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
What is backing rod for?
Backing rod goes into deeper joints as a matter of course. It controls the depth and stops the sealant bonding to the back.
Do you do commercial work?
Yes. We’ve worked for hotels, offices and other businesses.
Can you quote for more than one area?
Yes, we can. More than one area can be quoted together.
How long will you be here?
It depends on the size of the job, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We will tell you when we quote.
What we cannot put right
Some problems need a builder, plumber or other trade rather than us:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracked brickwork or render that needs a builder or plasterer
- Failed render or damaged cladding panels
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Joints and surfaces we work on
- Joints between brick and frames
- Façade panels
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
The process
Good joint work is mostly preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours for a handful of joints, longer for a whole elevation. Parking around Harefield is usually easier than in a town centre, but mention any lanes, gates or long drives. For outside work, side access and the height of the joints help us plan.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Before we arrive
- Keep children and pets away from the work area
- Try not to wet indoor joints just before the visit
- Move anything stored near the joints
Ask for a quote
There’s no standard price list. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or email us.
Read more
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
Landlords and letting agents in Harefield can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
What external mastic looks like in Harefield
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Ickenham Hall (about 3.4 miles south-east) are a reminder that the area around Harefield has older buildings as well as new. 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 Harefield Baptist Church, older walls, gutters and the joints where extensions meet them need a flexible sealant. For landlords with property near Denham station, split movement joints are easy to miss on a rental until damp shows inside. If you look after a building such as Harefield Infant School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Harefield is about 3 miles south of Rickmansworth, in Buckinghamshire. If you need external mastic in Harefield, it’s easy to get a quote: please ring 0345 464 0079 or send us an email. We’re based in Crawley and cover Buckinghamshire, Harefield included. Harefield is one of 263 towns and villages in Buckinghamshire we cover. We also work in London, about 18 miles from Harefield.
Our applicators cover all of UB9 for external mastic and the streets around it. Local streets include High Street, Vernon Drive and New Park Road, all of which we cover. Other places close to Harefield include Hill End (1 mile north), Woodcock Hill (1 mile north-east), Batchworth Heath (2 miles north-east), Batchworth (2 miles north-east) and Mill End (2 miles north). Larger places within reach include High Wycombe (12 miles west), Chesham (9 miles north-west), Marlow (13 miles west), Amersham (7 miles north-west), Beaconsfield (7 miles west) and Chalfont St Peter (3 miles west).
Around Harefield
Around Harefield, our work takes us to homes and buildings near The Green, The King's Arms Public House and The Harefield Academy. Harefield’s nearest station is Denham station, about 2 miles south. A little further out are Harefield Hospital (within half a mile north-west) and Chiltern Open Air Museum (3.4 miles north-west). For a walk, there’s Horse Shoe Bay and Dews Farm Sand Pits.