Kent · England
Harrietsham External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for householders, landlords and businesses in Harrietsham. Fully insured, ARBOMaster approved and guaranteed for a year.
- Rain getting behind render or cladding at a joint
- Weathered mastic that no longer stretches
- Movement joints filled with mortar instead of sealant
How we handle external mastic in Harrietsham
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing. If you have panel joints letting water in and water getting into walls through failed joints, we can help, whatever the surface.
Houses in smaller places like Harrietsham can stand more in the open than those in a built-up town, and walls and rooflines facing the weather take the worst of it. Joints on those sides are generally the first to go.
You’re covered for a year from the day we finish. If there’s a problem with it, please phone 0345 464 0079 or email us.
- Location
- Harrietsham (ME17)
- Region
- Kent
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
For landlords and businesses
If you manage several properties in or around Harrietsham, jobs at different addresses can go on one quote. Send us the addresses and the work at each.
Letting agents and landlords in Harrietsham can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.
What sealant work cannot fix
We’ll always be straight with you, so here’s what sealant can’t fix:
- Subsidence or other structural problems
- Loose or hollow render, which needs re-rendering
- Damp that isn’t coming from the joint
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly before booking.
Surfaces we seal
- Brickwork movement joints
- Façade panels
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
Quotes for external mastic in Harrietsham
You’ll get a clear quote before we start. It takes into account:
- The size of the job
- How much old sealant there is and how hard it is to remove
- Whether there’s mould to deal with
- How many rooms, windows or areas are involved
What you pay reflects the work, not a rough estimate. That is why we ask a few questions first and agree the price before starting.
Asking for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Access, such as stairs, a lift or height
- The rough size of the job
- Whether it’s a home or a business
- Any previous sealing or DIY work
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we will explain what’s involved before giving you a price.
What happens if it’s left?
It often makes sense to reseal all the failing joints on an elevation together. They’ve weathered the same way, and access only has to be arranged once. Homes in smaller places like Harrietsham 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.
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why book with us
- Full insurance on every job
- Tidy, careful work
- Quality sealants from Arbo and Everbuild
- More than 20 years in sealant work
The process
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The work itself takes anything from a few hours to several days, depending on the building, including the tidy-up. For a job in Harrietsham, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- Both sides are cleaned back to sound material and primed if needed.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Before we arrive
- For business premises, tell us about site rules or sign-in
- Mention any parking rules near the property
- Keep children and pets away from the work area
How to get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. Whenever you are ready, phone 0345 464 0079 or drop us an email.
Advice
What we’re called out for in Harrietsham
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and speed up the damage.
These are the problems we’re asked about most:
- Old sealant gone brittle and cracked
- Joints with sealant missing in places
- Weeds or debris growing in open joints
- Damp patches traced to an open external joint
For site and facilities teams at buildings such as Harrietsham Church of England Primary School, larger buildings have long runs of movement joint that eventually need resealing.
Before booking anyone
- When the joint can take water or movement
- Whether all the old sealant comes out first
- Whether they’re fully insured
- Whether you can choose the colour
Harrietsham questions
Do you cover smaller places like Harrietsham?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
I let a flat near Harrietsham station. Can you help?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Is the work guaranteed?
Yes. All our work carries a 12-month guarantee.
Can you do several jobs on one visit?
Yes. Several rooms, windows or areas can go on one quote.
When is the sealant fully cured?
Different products cure at different speeds, so follow the cure time we give you.
Where are you based?
Mr Mastic is based in Crawley. We cover Harrietsham and the rest of Kent, along with the rest of our area.
Can you reach joints on upper floors?
Each building is different. Tell us the height, the number of joints and what’s below them, and we will confirm what access is needed.
Is it messy?
No. We protect the surfaces around the joints, and we tidy up before we go.
What external mastic looks like in Harrietsham
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. Historic houses like Leeds Castle (about 2.2 miles west) are a reminder that the area around Harrietsham 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.
For landlords with property near Harrietsham station, outside joints that have cracked can let damp into a rental, so check them between lets. In the older streets around Catholic Church of the Good Shepherd, an extension built onto an older house moves differently, and the joint between them takes the strain.
Harrietsham is about 7 miles east of Maidstone, in Kent. Every kind of property in Harrietsham can book us for external mastic. Every job comes with our one-year guarantee. Harrietsham is one of 922 places in Kent where we work. You can also see our page for Chelmsford, about 35 miles away.
All of ME17 is within our area for external mastic, from the main roads to the quietest streets. That includes homes and businesses on Church Road, Station Road and Norris Walk and the roads around them. Nearby, we also carry out external mastic in Marley (1 mile east), Pollhill (1 mile west), Chegworth (1 mile west), Sandway (1 mile south-east) and Platt's Heath (1 mile south). Within a short drive, we also cover Maidstone (7 miles west), Ashford (11 miles south-east), Sittingbourne (7 miles north), Faversham (10 miles north-east), Minster (13 miles north-east) and Kings Hill (12 miles west).
Landmarks near Harrietsham
We work in homes and buildings around Kiln Wood, The Lenham School and The Roebuck Public House and the streets around them. There’s a railway station in Harrietsham itself: Harrietsham station. A little further out are The Dog Collar Museum (2.1 miles west) and Leeds Castle (2.2 miles west).
Can I do it myself?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.