Surrey · England
External Mastic in Selsdon
Movement joints in Selsdon need attention? We remove the old material, prepare the joints and seal them properly, with a 12-month guarantee.
- Weathered mastic that no longer stretches
- Movement joints filled with mortar instead of sealant
- Sealant that has lost its bond to the brick or render
What affects the quote in Selsdon
You will get a clear quote before we start. It’s based on:
- How many areas need sealing
- How much old sealant there is and how hard it is to remove
- How easy the joints are to reach
- Which sealant suits the joint
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. You will know the price before we begin.
What we need to know
To help us quote quickly, let us know:
- The type of property
- The problem you’ve noticed
- The rough size of the job
- If someone has resealed it before
We quote each job on its own, so start by telling us what you need. Just call 0345 464 0079 or email us with the details and send photos if you have them.
External mastic in Selsdon, done properly
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. If you have weathered mastic that no longer stretches and gaps where render, brick and frames meet, we can help, whatever the surface.
In and around Selsdon, older properties sit alongside newer ones, each with its own outside joints. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
A one-year guarantee comes as standard, so you are not left on your own once the job is done.
- Location
- Selsdon (CR2, CR0)
- Wider area
- Surrey
- Cover
- A year, on every job
- Quotes
- A clear price before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How it works
Before we leave, we go over the finished joints with you. The visit itself generally takes a few hours for a handful of joints, longer for a whole elevation, depending on the size of the job. A visit to Selsdon is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
How to prepare
- Move anything stored near the joints
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
Get a quote
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job, and we will come back to you with a quote.
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Landlord and commercial work in Selsdon
Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Signs you need external mastic in Selsdon
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. The joint cannot move, so the wall cracks somewhere else instead.
It’s worth asking for a quote if you see:
- Sealant that has lost its bond to the brick or render
- Weeds or debris growing in open joints
- Rain getting behind render or cladding at a joint
- Joints pointed up with cement by mistake
If you live in an older home near St Francis, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Before booking anyone
- How much experience the applicator has
- What guarantee comes with the work
- What happens if the job turns out different
- What insurance they hold
DIY versus a professional finish
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
Why it’s worth doing now in Selsdon
Resealing a run of joints in one go is normally better than patching one at a time. They’ve weathered the same way, and access only has to be arranged once. In an older home around Selsdon, damp from a failed joint can get into timber and plaster, and that is a much bigger job than renewing the sealant.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Why choose Mr Mastic in Selsdon
- We agree the colour with you first
- Arbo and Everbuild products
- Over 20 years’ experience
- Sealant colour chosen to suit
See what affects the cost and what customers say.
Selsdon: your questions answered
Do you cover smaller places like Selsdon?
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.
Do you work for landlords with property near Sanderstead station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just ring 0345 464 0079 or email us with the address and what needs doing, and we will give you a clear quote.
What does external mastic cost?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. You will get a clear quote before we start.
Can you seal joints between render and window frames?
Yes. Where different materials meet is one of the most common joints we seal. We use a flexible sealant suited to both surfaces with primer where required.
Will you leave a mess?
We keep the work tidy. We protect what’s around the joints, and we clear up when we’re done.
Can you do several jobs on one visit?
Yes. Just list everything you need.
Can new sealant go over the old?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Do you guarantee your work?
Yes: twelve months. If there’s a problem with our work in that time, tell us and we’ll put it right.
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Point out the joints to other trades
- Wash walls gently around the sealant
- Fix overflowing gutters above sealed joints
- Walk round the building once a year and look at the joints
Only paint over the joint if we have confirmed the sealant can take paint. Paint can crack on a flexible joint and spoil the finish.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years.
Places near Selsdon
Other services in Selsdon
Selsdon buildings and the weather
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. Historic houses like Addington Palace (about 1 mile north-east) are a reminder that the area around Selsdon has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For landlords with property near Sanderstead station, outside joints that have cracked can let damp into a rental, so check them between lets. Managing a site like Selsdon Primary and Nursery School? Then its movement joints, gutters and trims need looking after like any other building’s.
Selsdon is about 2 miles south-east of Croydon, in Surrey. If you need external mastic in Selsdon, please ring 0345 464 0079 or email us for a quick quote. We cover Surrey from our Crawley base, Selsdon included. We cover 395 towns and villages across Surrey, large and small. We also work in London, around 11 miles away.
Postcode districts we cover here for external mastic: CR2 and CR0. Whether your property is on York Road, Byron Road and Abbey Road or anywhere close by, we can help. We also cover the places around Selsdon: Forestdale (1 mile east), Addington (1 mile north-east), Sanderstead (1 mile south-west), Coombe (1 mile north-west) and Farleigh (2 miles south-east). We also work in nearby towns such as Epsom (9 miles west), Horley (13 miles south-west), Redhill (9 miles south-west), Ewell (9 miles west), Reigate (10 miles south-west) and Caterham (4 miles south).
Landmarks near Selsdon
Around Selsdon, our work takes us to homes and buildings near The Sir Julian Huxley pub, The Quest Academy and Littleheath Woods, among other places. For rail, the closest station is Sanderstead station, roughly 1.7 miles west of the centre. Well-known places in the area include St George's Walk (2.7 miles north-west) and Croydon Airport Visitor Centre (2.9 miles west). Green spaces nearby include Duppas Hill and Bramley Bank.