Surrey · England
External Mastic in St John's
External mastic across St John's and nearby, with old sealant always removed completely and a 12-month guarantee.
- Failed sealant between panels on a façade
- Movement joints filled with mortar instead of sealant
- Moss and dirt in joints with no sealant left
Signs you need external mastic in St John's
Joints sealed without backing rod, or far too deep, rarely last. Sealant bonded to three sides has nowhere to go and tears as soon as the joint widens.
The most common problems we see are:
- Moss and dirt in joints with no sealant left
- Rigid filler in a joint that should flex
- Rain getting behind render or cladding at a joint
- Sealant that has lost its bond to the brick or render
Schools such as The Winston Churchill School A Specialist Sports College are buildings too, and larger buildings have long runs of movement joint that eventually need resealing.
Questions to ask before you book
- What insurance they hold
- How much experience the applicator has
- Whether all the old sealant comes out first
- What the cure time is
External mastic in St John's, done properly
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 brickwork movement joints, concrete & block and render & cladding joints, and common reasons people get in touch are weathered mastic that no longer stretches and cracked joints where brick meets render or frames.
Around St John's, garages, outbuildings and extensions all add to the joints on the outside of a home. Gutter ends, garage door frames and the joints where an extension meets the house are typical spots for leaks.
Whatever the size of the job, it’s backed by our 12-month guarantee in St John's and across Surrey.
- Place
- St John's (GU21, GU22)
- Wider area
- Surrey
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
How long the joints last depends on use and care. Here’s what we suggest:
- Have failed joints looked at early
- Show decorators and builders where the movement joints are
- Never let anyone fill a movement joint with mortar
- Avoid pressure-washing directly into sealant joints
Keep pressure washers away from the sealant. High-pressure water can lift the edges and let water in behind.
If you can see gaps, plants or bare sections in a joint, have it checked. Earlier resealing means a smaller job and a better result.
Landlords, agents and businesses in St John's
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
Failed sealant is one of the commonest items on a check-out report, and it’s quick to put right between tenancies. Several properties can go on one quote.
What we do, step by step
There’s no need to move everything out before we come, only the area right around the joints. Everything nearby is protected, and the job takes anything from a few hours to several days, depending on the building for a typical job. In a smaller place like St John's, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- 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.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Mention any sign-in or site rules at work premises
- Where the joints are inside, avoid wetting them before we arrive
- Mention if the joints have been sealed before
Get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
Read more
DIY versus a professional finish
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Towns and villages near St John's
What else we do in St John's
Outside joints around St John's
Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
In the older streets around St John's Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Letting a property close to Woking station? Then split movement joints are easy to miss on a rental until damp shows inside.
St John's is about 1 mile west of Woking, in Surrey. Whether you are in the middle of St John's or further out, we cover external mastic for every kind of property. 395 places in Surrey are on our list, from the larger towns to small villages. For nearby work, see our Reading page.
We work across GU21 and GU22 for external mastic. You will find streets such as Pond Road, Copse Road and Raglan Road, all of which we cover. With the A324 close by, St John's is easy for our applicators to reach for external mastic. Neighbouring places we cover for external mastic include Goldsworth Park (1 mile north-east), Woking (1 mile east), Westfield (2 miles south-east), Horsell (2 miles north-east) and Mimbridge (2 miles north). Further out, we also cover Guildford (5 miles south), Camberley (6 miles west), Epsom (14 miles east), Farnham (11 miles south-west), Ewell (15 miles east) and Egham (8 miles north).
What’s near St John's
Around St John's, our work takes us to homes and buildings near Hoe Valley School, The Oaktree School and Royal Oak pub. The closest station to St John's is Woking station, about 1.6 miles east of the centre. A little further out are Brookwood Hospital (1 mile west) and The Peacocks (1.6 miles east). The countryside around St John's includes Brookwood Lye.
Honest limits
We will not take on work that won’t last, so here’s what sealant cannot put right:
- Cracks in the bricks or render themselves, away from the joints
- Walls that need new movement joints cut into them
- Damp that is not coming from the joint
If you’re not sure, just phone 0345 464 0079 or email us and we will give you a straight answer before you book.
Joints and surfaces we work on
- Joints between brick and frames
- Copings & trims
- Concrete & block
- Façade panels
- Render & cladding joints
- Brickwork movement joints
Why deal with it now?
Done well, a resealed joint is a neat, straight line that suits the wall. A rushed bead with no backing looks untidy and does not last. Around St John's, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Why book with us
- Every job guaranteed for a year
- Any old sealant cut out fully, not covered over
- We leave the area clean and tidy
- We are fully insured
Take a look at what affects the cost or what customers say.
FAQs for St John's
Can you help a landlord with a rental near Woking station?
Yes, we work for letting agents and landlords. Just phone 0345 464 0079 or send us an email and tell us about the property, and we’ll send you a clear quote.
Will you come out to St John's?
Yes. St John's is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
What sealant do you use?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice.
Are you an approved applicator?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We’ll give you the cure time for the product we used before we leave.
Do I have to be there?
If the work is inside, we need someone to let us in. Once we have agreed the job, you do not need to watch us work.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us.
What is a movement joint?
A vertical gap in a long brick wall is generally a movement joint. It gives the wall room to move, and it should be sealed with a flexible sealant.