Buckinghamshire · England
Gerrards Cross External Mastic
Professional external mastic in and around Gerrards Cross, with old sealant always removed completely and a 12-month guarantee.
- Damp patches traced to an open external joint
- Joints where the bead has come unstuck
- Old sealant gone brittle and cracked
How we handle external mastic in Gerrards Cross
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing and we use one wherever it does. We work on façade panels, concrete & block and brickwork movement joints, and the jobs we see most are leaking joints around cladding and façade panels and weathered mastic that no longer stretches.
Houses in smaller places like Gerrards Cross can stand more in the open than those in a built-up town, so exposed walls and rooflines take more wind-driven rain. That is where gutter joints and wall joints tend to fail first.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we’ll put it right.
- Where
- Gerrards Cross (SL9)
- Wider area
- Buckinghamshire
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Can I do it myself?
A DIY attempt does not rule out a professional job. We cut it out and start again.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
Places near Gerrards Cross
Also in Gerrards Cross
Common problems we fix in Gerrards Cross
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and speed up the damage.
Common reasons people contact us are:
- Gaps where render, brick and frames meet
- Movement joints with cracked, split or missing sealant
- Movement joints filled with mortar instead of sealant
- Damp patches traced to an open external joint
For an older house near a landmark such as St James Church, an extension built onto an older house moves differently, and the joint between them takes the strain.
Before booking anyone
- Who does the work, and how experienced they are
- How long to leave it before use
- What preparation is included
- Whether they seal over old material or remove it
Why deal with it now?
Running new sealant over the old bead rarely lasts. The new layer cannot bond properly to old, weathered material, so we always take the old sealant out. In an older home around Gerrards Cross, damp from a failed joint can get into timber and plaster, and that’s a much bigger job than renewing the sealant.
What you pay reflects the work, not guesswork. That’s why we ask a few questions first and give you a clear quote before any work starts.
Why us?
- 20+ years of sealant experience
- Tidy, careful work
- Colour agreed with you before any work starts
- Sanitary silicone with an anti-fungal additive in wet areas
See our cost guide and our reviews.
Gerrards Cross buildings and the weather
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.
Rented homes near Gerrards Cross station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. Managing a site like The Gerrards Cross CofE School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Gerrards Cross is about 5 miles north-east of Slough, in Buckinghamshire. Whether you’re in the middle of Gerrards Cross or further out, external mastic is available for homes and businesses alike. Our area takes in 263 places across Buckinghamshire. Our Reading page covers work nearby.
We cover every part of SL9 for external mastic. If you need external mastic at a property on Station Road, East Common and Oxford Road or a nearby road, our applicators can take on the job. Being close to the A40 and A413, Gerrards Cross is easy for our applicators to reach for external mastic. Nearby, we also carry out external mastic in Tatling End (1 mile south-east), Fulmer (1 mile south), Hedgerley Green (2 miles west), Higher Denham (2 miles east) and Baker's Wood (2 miles east). Larger places within reach include High Wycombe (9 miles west), Chesham (9 miles north), Marlow (9 miles west), Amersham (7 miles north), Beaconsfield (4 miles north-west) and Princes Risborough (15 miles north-west).
Around Gerrards Cross
In Gerrards Cross, that means homes and buildings near St Mary's School, The Chalfonts Community College and Bulstrode Park, among other places. There’s a railway station in Gerrards Cross itself: Gerrards Cross station. Well-known places in the area include Chiltern Open Air Museum (3.8 miles north) and Chalfonts and Gerrards Cross Hospital (1.7 miles north). For a walk, there’s Horse Shoe Bay and Church Wood.
Landlord and commercial work in Gerrards Cross
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Quotes for external mastic in Gerrards Cross
The quote reflects the job in front of us. We take into account:
- Any mould that needs treating
- Which sealant suits the joint
- The old material and how stubborn it is
- The number of rooms or windows
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote.
What to tell us for a quote
To make quoting easier, please include:
- Where the job is, and your postcode
- The type of property
- Roughly how big the job is
- Any previous sealing or DIY work
Want a quote for external mastic? Please ring 0345 464 0079 or email us with a few details. You will know what we plan to do, and what it will cost, before any work begins.
How the visit works
There’s no need to move everything out before we come, just the space around the work. Everything nearby is protected, and the work takes a few hours for a handful of joints, longer for a whole elevation in most cases. In a smaller place like Gerrards Cross, 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.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Getting ready for the visit
- Let us know about parking restrictions
- Keep pets and children clear of the area while we work
- For business premises, tell us about site rules or sign-in
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that is easy.
Related advice
What sealant work cannot fix
We will not take on work that won’t last, so these are the limits:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Movement that’s more than a sealant joint can take
- Render that is blown, hollow or coming away
If you are not sure, just phone 0345 464 0079 or send us an email and we will give you a straight answer before you book.
Surfaces we seal
- Brickwork movement joints
- Concrete & block
- Façade panels
- Joints between brick and frames
- Copings & trims
- Render & cladding joints
Questions from Gerrards Cross
Will you come out to Gerrards Cross?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you cover Gerrards Cross for external mastic?
Yes. We work across London and the South East, and Gerrards Cross is part of that. You can ring 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll give you a clear quote.
Is it OK to seal over old sealant?
No, and we never do. It may look fine at first, but the new bead soon lifts. The old sealant has to come out completely.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Is it worth trying it myself?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Can you seal joints between render and window frames?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
Do you have insurance?
Yes. We’re fully insured, and we’ve been doing sealant work for more than 20 years.
Is there a guarantee?
Yes. All our work carries a one-year guarantee.