Hertfordshire · England
Hunsdonbury External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for Hunsdonbury, backed by a one-year guarantee. Call for a quick quote.
- Rain getting behind render or cladding at a joint
- Failed seals between different materials
- Leaking joints around cladding and façade panels
External mastic in Hunsdonbury
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We take the old material out and do it properly. We’re often asked to deal with weathered mastic that no longer stretches and joints where the bead has come unstuck, on façade panels, concrete & block and render & cladding joints.
Somewhere as small as Hunsdonbury, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
You get a 12-month guarantee, the same in Hunsdonbury as everywhere else we work.
- Place
- Hunsdonbury (SG12)
- Wider area
- Hertfordshire
- Guarantee
- One year on every job
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Hunsdonbury buildings and the weather
Historic houses like Much Hadham Palace (about 4 miles north) are a reminder that the area around Hunsdonbury 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. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Rented homes near Roydon station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. If you live in an older home near St Francis Chapel, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Hunsdonbury is about 3 miles north-west of Harlow, in Hertfordshire. We carry out external mastic for homes and businesses in Hunsdonbury, as part of our work across Hertfordshire. Hunsdonbury is one of 381 towns and villages in Hertfordshire where we work. Chelmsford is on our list too, around 19 miles away.
We work across SG12 for external mastic. We cover properties on Acorn Street, Great Oak Court and Nine Ashes and the roads around them. We also cover the places around Hunsdonbury: Hunsdon (1 mile north), Widford (1 mile north), Nether Street (2 miles north), Wareside (2 miles north-west) and Babbs Green (2 miles north-west). Further out, we also cover Stevenage (13 miles north-west), Bishop's Stortford (6 miles north-east), Welwyn Garden City (11 miles west), Hoddesdon (4 miles south-west), Cheshunt (8 miles south-west) and Hatfield (12 miles west).
What’s near Hunsdonbury
Around Hunsdonbury, our work takes us to homes and buildings near The Fox & Hounds pub and Roydon Primary School. The closest station to Hunsdonbury is Roydon station, about 1.9 miles south of the centre. A little further out are Princess Alexandra Hospital (2.5 miles south-east) and Henry Moore Studios and Gardens (2.8 miles north-east). Not far away are Hunsdon Mead.
Work for landlords, hotels and businesses
Landlords and letting agents in Hunsdonbury can book us as well as householders. Resealing between tenancies keeps a property looking cared for.
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can go on one quote.
Quotes for external mastic in Hunsdonbury
The price is agreed before any work begins. It’s based on:
- Mould in or behind the old joints
- The number of rooms or windows
- Access and height
- The old material and how stubborn it is
The cost reflects the work involved, not a rough estimate. That is why we ask about the job first and agree the price before starting.
What we need to know
Before you ask for a quote, have a think about:
- Access, such as stairs, a lift or height
- A few pictures by email, if you can
- What’s wrong with the joints now
- Any previous sealing or DIY work
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is.
When to call us in Hunsdonbury
Many joints fail because they were sealed too deep or with nothing behind them. If the sealant sticks to the back as well as the sides, it cannot stretch and rips as the joint opens.
The most common problems we see are:
- Water getting into walls through failed joints
- Failed seals between different materials
- Leaking joints around cladding and façade panels
- Weeds or debris growing in open joints
If you look after a building such as Hunsdon Junior Mixed and Infant School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Before you book anyone
- Whether the sealant suits the joint
- What the cure time is
- What guarantee comes with the work
- How the joint is cleaned and prepared
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Questions from Hunsdonbury
Can you do external mastic in Hunsdonbury?
Yes. Our work covers London and the South East, and Hunsdonbury is part of that. Just ring 0345 464 0079 or email us with a few details of the job.
I let a flat near Roydon station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
How long does external mastic take?
A typical job takes anything from a few hours to several days, depending on the building, including the preparation. Your quote will say how long we expect yours to take.
Are you fully insured?
Yes, we’re fully insured.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
What should I tell you?
The location, the problem and the rough size of the job. Photos by email help too.
What is backing rod for?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding so the bead can stretch.
Are you ARBOMaster approved?
Yes. Mr Mastic is an ARBOMaster approved applicator, and we are fully insured.
Different surfaces, different methods
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. The old joint is removed and a sealant that bonds to both sides goes in.
Cladding and façade panels
Panel systems often rely on sealant between and around the panels. We reseal them with a sealant suited to the panel material.
What we do, step by step
When we arrive, we look over the joints with you first. Surfaces next to the work are protected before work begins. The work generally takes a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Hunsdonbury, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- 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.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Mention any sign-in or site rules at work premises
- Tell us about any water getting in
- Let us know about earlier repairs to the joints
Getting a quote
Getting a quote is simple: tell us what needs doing and where, and roughly how big it is. A few pictures by email make the job easier to understand, and we will take it from there.
Advice
Towns and villages near Hunsdonbury
What else we do in Hunsdonbury
What sealant work can’t fix
In fairness, some problems need a different trade:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracked brickwork or render that needs a builder or plasterer
- Loose or hollow render, which needs re-rendering
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Where we work in Hunsdonbury
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Concrete & block
- Brickwork movement joints
- Copings & trims