Kent · England
External Mastic in Seal
External mastic across Seal and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Panel joints letting water in
- Weathered mastic that no longer stretches
- Failed seals between different materials
External mastic in Seal, done properly
For buildings in Seal, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean, sound faces and a controlled depth. We work on render & cladding joints, concrete & block and brickwork movement joints, and common reasons people get in touch are sealant that has lost its bond to the brick or render and moss and dirt in joints with no sealant left.
Somewhere as small as Seal, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Joints on those walls need a sealant that moves with the building and stays in place.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Seal (TN15)
- Region
- Kent
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Your questions about external mastic in Seal
Do you cover smaller places like Seal?
Yes, Seal is covered. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can you help a landlord with a rental near Bat & Ball station?
Yes, landlords and agents are among the people we work for. You can ring 0345 464 0079 or email us with the details for a clear quote.
When is the sealant fully cured?
That depends on the sealant used, so follow the cure time we give you.
Are you insured?
Yes. Mr Mastic is fully insured.
What should I tell you?
Just the basics: the address or postcode, what’s wrong and any access issues. Then ring 0345 464 0079 or drop us an email.
How long does external mastic last?
It varies with how exposed the wall is and how much the joint moves. Look for splits, hardening or edges coming away, and reseal at that point.
Will the old sealant be removed?
Yes. Sealing over old sealant is the main reason resealing fails early, so we never do it.
Can you seal joints between two different materials?
Yes. Where different materials meet is one of the most common joints we seal. We use a flexible sealant suited to both surfaces, primed where needed.
What we can’t put right
We won’t take on work that won’t last, so these are the limits:
- Loose or hollow render, which needs re-rendering
- Walls that need new movement joints cut into them
- Movement that’s more than a sealant joint can take
If you are not sure, just phone 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Where we work in Seal
- Brickwork movement joints
- Joints between brick and frames
- Concrete & block
- Render & cladding joints
- Copings & trims
- Façade panels
Landlord and commercial work in Seal
In hotels, rooms out of use cost money, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
Why act early in Seal
Mortar or ordinary filler might look like a quick way to close an open joint, but it stops the joint moving. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. Around Seal, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
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 will know the price before we begin.
What you get with us
- Anti-fungal silicone where joints get wet
- Homes, businesses and hotels
- Tidy, careful work
- Fully insured
Take a look at what affects the cost or what customers say.
What happens on the day
There isn’t much for you to do on the day. Show us the job and we’ll take it from there. The job generally takes a few hours for a handful of joints, longer for a whole elevation, including the tidy-up. In a small place like Seal, access is normally the main thing to plan. 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.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Mention any parking rules near the property
- On commercial sites, let us know about site rules
- Move anything stored near the joints
Getting a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. When it suits you, ring 0345 464 0079 or send us an email.
Advice
Seal buildings and the weather
With historic houses such as Knole House (about 1.8 miles south) nearby, there’s older building stock in the area around Seal as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as Seal Church of England Voluntary Controlled Primary School, its movement joints, gutters and trims need looking after like any other building’s. In the older streets around Church of St Peter and St Paul, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Seal is about 2 miles north-east of Sevenoaks, in Kent. Homes, rented property, offices and hotels in Seal is covered for external mastic, old or new, large or small. The work is guaranteed for a year. Seal is one of 922 places in Kent where we work for external mastic. London is on our list too, about 20 miles from Seal.
All of TN15 is covered for external mastic. You will find streets such as High Street, Church Road and Jubilee Rise, all of which we cover. Nearby, we also carry out external mastic in Greatness (1 mile west), Godden Green (1 mile south), Styants Bottom (2 miles east), Stone Street (2 miles south-east) and Bitchet Green (2 miles south-east). Within a short drive, we also cover Maidstone (13 miles east), Dartford (11 miles north), Royal Tunbridge Wells (11 miles south), Gravesend (12 miles north-east), Tonbridge (7 miles south) and Northfleet (11 miles north-east).
What’s near Seal
We work in homes and buildings around Wildernesse School, Kemsing Down and The Five Bells Public House and the streets around them. Seal’s nearest station is Bat & Ball station, roughly 1.1 miles west. A little further out are Sevenoaks Hospital (1.1 miles west) and Sevenoaks Museum (1.7 miles south-west). Green spaces nearby include Dryhill Nature Reserve.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Nearby places to Seal
More services for Seal
When to call us in Seal
Joints sealed without backing rod, or far too deep, rarely last. Sealant bonded to three sides has nowhere to go and rips as the joint opens.
The problems people generally mention when they call include:
- Joints with sealant missing in places
- Sealant that has lost its bond to the brick or render
- Failed sealant between panels on a façade
- Water getting into walls through failed joints
Rented homes near Bat & Ball station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
What your quote should include
- Who turns up on the day
- What preparation is included
- How hidden problems are handled
- What product goes in the joint
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Check the sealant is paintable before painting near it
- Have failed joints looked at early
- Do not let climbing plants root in the sealant
- Fix overflowing gutters above sealed joints
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
A joint that has stopped moving pushes the movement elsewhere, often as cracks near the joint. Catch it early and you reduce the risk.