Medway · England
Kemsley Street External Mastic
Specialist external mastic for Kemsley Street: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Failed sealant between panels on a façade
- Sealant pulling away from one side of the joint
- Gaps where render, brick and frames meet
Honest limits
We will always be straight with you, so here’s what sealant cannot fix:
- Loose or hollow render, which needs re-rendering
- Subsidence or other structural problems
- Cutting new joints into brickwork, which is building work rather than sealant work
If in doubt, ring 0345 464 0079 or email us and we’ll say what we think before you book.
Where we work in Kemsley Street
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Concrete & block
- Copings & trims
How we handle external mastic in Kemsley Street
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product. If you’re dealing with damp patches traced to an open external joint and weeds or debris growing in open joints, we can put it right, whatever the surface.
External sealant needs dry, clean surfaces, so work around Kemsley Street is planned for dry weather. Let us know about access to every wall, plus any garages or outbuildings.
Whatever the size of the job, you get the same one-year guarantee in Kemsley Street and across Medway.
- Place
- Kemsley Street (ME7)
- Region
- Medway
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so just mention it when you contact us.
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.
Do you need external mastic in Kemsley Street?
Sometimes a movement joint was filled with mortar or a rigid filler. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Common reasons people contact us are:
- Rain getting behind render or cladding at a joint
- Movement joints with cracked, split or missing sealant
- Gaps where render, brick and frames meet
- Movement joints filled with mortar instead of sealant
If you live in an older home near Church of St Peter, older walls, gutters and the joints where extensions meet them need a flexible sealant.
What to look for in a quote
- Who does the work, and how experienced they are
- Which colour the sealant will be
- Is the old sealant removed completely?
- What insurance they hold
Questions from Kemsley Street
Do you cover Kemsley Street for external mastic?
Yes, Kemsley Street is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or send us an email and tell us what needs doing.
Can you help a landlord with a rental near Rainham (Kent) station?
Yes. We work for landlords and letting agents as well as householders, and several properties can go on one quote. You can ring 0345 464 0079 or drop us an email with the details for a clear quote.
What sealant do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
What do you need from me for a quote?
Where the job is, what the problem is and roughly how big it is. If you can, email a few photos.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so the joint is cleaned back first.
Where are you based?
Mr Mastic is based in Crawley. We cover Kemsley Street and the rest of Medway.
Can you seal joints between two different materials?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
Do the sealants smell?
Sometimes, a little. Any smell clears as the sealant cures, and ventilation helps.
Landlord and commercial work in Kemsley Street
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can go on one quote.
Housing providers, facilities teams and property managers book us too in Kemsley Street and across Medway. We can quote a run of properties together, and we’re fully insured.
Towns and villages near Kemsley Street
Other services in Kemsley Street
External mastic in Kemsley Street: local notes
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as Deanwood Primary School, its movement joints, gutters and trims need looking after like any other building’s. Rented homes near Rainham (Kent) station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Kemsley Street is about 3 miles south of Gillingham, in Medway. For external mastic in and around Kemsley Street, it’s easy to get a quote: please phone 0345 464 0079 or send us an email. We cover Medway from our Crawley base. Our Medway coverage runs to 68 places, and Kemsley Street is one of them. We also work in Chelmsford, about 28 miles from Kemsley Street.
Work in ME7 works the same way as everywhere else we cover. We also cover Bredhurst (1 mile west), Scragged Oak (1 mile south), Dunn Street (1 mile south-west), Park Wood (1 mile north-east) and Lower Cox Street (1 mile south-east). Further out, we also cover Gillingham (3 miles north), Chatham (3 miles north-west), Rochester (6 miles north-west), Strood (6 miles north-west), Luton (3 miles north-west) and Twydall (3 miles north).
What’s near Kemsley Street
Typical jobs here are in homes near Rainham School for Girls and Levan Strice, among other places. The closest station to Kemsley Street is Rainham (Kent) station, roughly 2.5 miles north-east. Well-known places in the area include KIMS hospital (3.5 miles south-west) and Allington Castle (4.3 miles south-west). Green spaces nearby include Burham Down and Detling Hill.
How to look after the new joints
A little care helps the new joints last. We recommend:
- Show decorators and builders where the movement joints are
- Deal with leaking gutters that soak the joints below
- Leave the joints unpainted unless we have said otherwise
- Avoid pressure-washing directly into sealant joints
Keep the joints clear of soil, plants and climbing growth. Damp material against the sealant shortens its life.
A joint that has stopped moving pushes the movement elsewhere, often as cracks near the joint. Resealing it early helps prevent that.
What affects the cost of external mastic
We don’t publish a price list. What we look at:
- The number of rooms or windows
- The old material and how stubborn it is
- The size of the job
- Which sealant suits the joint
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs. Ask us for a quote and we will go through it with you.
Helping us quote
To help us quote quickly, let us know:
- Where the property is
- Roughly how big the job is
- What’s wrong with the joints now
- Any access issues, like height or stairs
Want a quote for external mastic? Please call 0345 464 0079 or send us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
How the visit works
A visit follows a simple pattern: we look at the joints together, protect the area around them, do the work and tidy away. It normally takes a few hours for a handful of joints, longer for a whole elevation. In a small place like Kemsley Street, access is usually the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Preparing for the visit
- Tell us about any water getting in
- Tell us if parking is tricky
- Keep pets and children clear of the area while we work
Ask for a quote
There’s no standard price list. Instead, we give you a clear price for your job. To arrange one, ring 0345 464 0079 or email us.