South East England and London

External Mastic in Kent

We cover 922 towns and villages across Kent for external mastic, with old sealant always removed and a one-year guarantee on every job., done properly, with a clear quote before we start and a one-year guarantee.

Book external mastic in Kent

Call 0345 464 0079

Get a quick quote

External mastic in every part of Kent

Sealing brickwork movement joints, render, cladding and façade joints. Choose your town from the list to see local details, or call or email us for a quick quote.

Main towns

How external mastic works in Kent

Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. We work on copings & trims, brickwork movement joints and façade panels, and common reasons people get in touch are failed sealant between panels on a façade and joints with sealant missing in places.

Before we leave, we go over the finished joints with you and explain the cure time. The visit itself normally takes a few hours to a few days, depending on the length of joint and the access, depending on the amount of work.

First we look over the joints with you, agree which to renew and talk through access.
The old mastic and anything lodged in the joint is removed.
We clean both faces of the joint and prime them where the product calls for it.
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.

What affects the price in Kent

Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.

Why choose Mr Mastic

ARBOMaster approved applicator
180+ five-star Google reviews
Domestic, commercial and hotel work
More than 20 years in sealant work

Getting a quote

Want a quote for external mastic? Please call 0345 464 0079 or email us and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.

Near you in Maidstone

We work in homes and buildings around Paper Makers Arms, Maidstone Grammar School and St Philip's Church and the streets around them. Also close by are River Len LNR (less than half a mile north-east), South Borough Primary School (within half a mile south) and St Augustine Academy (1.2 miles west). For rail, the closest station is Maidstone West station, about 0.6 miles north-west. Other landmarks nearby include Maidstone Carriage Museum (within half a mile north-west) and Oakwood Hospital (1.8 miles west). For a walk, there’s Burham Down and Boxley Hills.

Outside joints across Kent

In Kent, external mastic work takes in houses, flats and commercial buildings, from Maidstone, Ashford and Canterbury to the quieter places in between. Outside joints can only be sealed when they’re dry, so the work is planned around the weather.

The South East is one of the drier parts of the UK, though outside sealant still needs a dry, clean joint, so work across Kent is planned around the weather. Along the coast in Kent, window and wall joints facing the sea take the brunt of the weather, so they’re often the first to fail. Good preparation and the right sealant help it cope.

Maidstone: Schools such as South Borough Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s. Letting a property close to Maidstone West station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.

How to look after the new joints

Joint life depends on how it’s used and looked after. Here’s what we suggest:

Have failed joints looked at early
Keep soil, plants and ivy away from the joints
Keep movement joints as flexible joints, not mortar
Keep water from gutters off the wall

Keep the joints clear of soil, plants and climbing growth. Damp material against the sealant shortens its life.

Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years.

Different surfaces, different methods

Cladding and façade panels

Cladding and façade panels are normally separated by sealed joints. We reseal them with a sealant suited to the panel material.

Render joints

Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.

What happens if it’s left?

Water gets in through a failed movement joint and can run behind render or cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it.

Questions to ask before you book

What happens if the job turns out different
What insurance they hold
How the surfaces are prepared before sealing
How long to leave it before use

What we are called out for in Kent

If plants are growing out of a joint, the sealant has normally failed or was never there. Roots and dirt hold water against the wall and speed up the damage.

It’s worth asking for a quote if you see:

Movement joints filled with mortar instead of sealant
Joints where the bead has come unstuck
Brick movement joints where the sealant has split
Old sealant gone brittle and cracked

Should I try it myself first?

A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.

If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly.

FAQs for Kent

How long should I leave it?

Most sealants are touch-dry well before they’re fully cured. We will give you the cure time for the product we used before we leave.

Will it make a mess?

No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.

Can new sealant go over the old?

No. New silicone will not bond to old silicone, and anything trapped underneath, including mould and water, stays there. It all has to come out first.

I’m a tenant. Can you help?

We can work for tenants, landlords or agents. Just make sure your landlord agrees.

Do you seal joints where cladding meets other materials?

Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.

Can you do several jobs on one visit?

Yes, and it often makes sense. Doing several areas at once is generally more efficient.

Is it OK to fill a movement joint with cement?

No. Mortar locks the joint solid, so the movement cracks the wall elsewhere. It needs a flexible sealant over backing rod.