Surrey · England
Crosswater External Mastic
External mastic in Crosswater from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Damp patches traced to an open external joint
- Failed sealant between panels on a façade
- Joints where the bead has come unstuck
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. A few tips:
- Tell anyone working on the walls about the movement joints
- Wash walls gently around the sealant
- Ask before painting over external sealant
- Clear growth from the base of walls and joints
Make sure anyone working on the wall later knows where the movement joints are. They should be kept open and resealed, not filled.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established so early resealing is worth it.
External mastic in Crosswater
On houses, flats and commercial buildings across Crosswater, we reseal joints in brickwork, render, cladding and façade panels. The preparation is the same whatever the wall: clean joint faces and the right depth. Common call-outs are for rigid filler in a joint that should flex and failed seals between different materials, on copings & trims, façade panels and brickwork movement joints.
Somewhere as small as Crosswater, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
Your job is guaranteed for a year, as with all our work.
- Place
- Crosswater (GU10)
- Wider area
- Surrey
- Cover
- A year, on every job
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
When to call us in Crosswater
Some movement joints have been pointed up with mortar by mistake. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Common reasons people contact us include:
- Joints where the bead has come unstuck
- Movement joints filled with mortar instead of sealant
- Weeds or debris growing in open joints
- Old sealant gone brittle and cracked
In the older streets around St John the Evangelist, an extension built onto an older house moves differently, and the joint between them takes the strain.
Before you book anyone
- Whether all the old sealant comes out first
- Are they insured?
- How the surfaces are prepared before sealing
- What happens if the job turns out different
Should I try it myself first?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
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.
External mastic in Crosswater: local notes
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Farnham Castle (about 4.9 miles north) nearby, there’s older building stock in the area around Crosswater as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material.
For site and facilities teams at buildings such as St John's CofE Aided Infant School, its movement joints, gutters and trims need looking after like any other building’s. For landlords with property near Farnham station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Crosswater is about 4 miles south of Farnham, in Surrey. If you need external mastic in Crosswater, please ring 0345 464 0079 or email us for a quick quote. We’re based in Crawley and cover Surrey. We cover 395 towns and villages across Surrey, from the larger towns to small villages. Our Reading page covers work nearby, about 22 miles away.
Here we cover the GU10 postcode area for external mastic. We also cover the places around Crosswater: Churt (1 mile south), Green Cross (1 mile south-east), Frensham (1 mile north-west), Barford (1 mile south) and Rushmoor (1 mile north-east). Within a short drive, we also cover Guildford (11 miles north-east), Woking (15 miles north-east), Camberley (13 miles north), Farnham (4 miles north), Frimley (12 miles north) and Haslemere (5 miles south-east).
Local landmarks in Crosswater
In Crosswater, that means homes and buildings near Crossways Inn and The Flashes. The nearest railway station is Farnham station, about 4.3 miles north. Well-known places in the area include Farnham Castle (4.9 miles north) and Chase Community Hospital (4.7 miles south-west). Green spaces nearby include Gibbet Hill and Upper Lake.
The process
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for a handful of joints, longer for a whole elevation. Somewhere like Crosswater needs a little journey planning: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Plan for the work area to be out of bounds to pets and children
- Clear the area around the work
- Let us know about parking restrictions
Get a quote
Getting a quote is simple: let us know what needs doing and where. A few pictures by email make the job easier to understand, and we’ll take it from there.
Related advice
Places near Crosswater
Also in Crosswater
Leave it or put it right?
Pointing a movement joint with mortar might seem a neat fix, but it locks the joint solid. The wall then cracks somewhere else. The correct repair is a flexible sealant with the right backing. Older cottages and farmhouses around Crosswater can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
The cost depends on how much there is to do, how much old material has to come out and how easy the joints are to reach. We give a clear quote before any work starts.
Why choose Mr Mastic in Crosswater
- Domestic, commercial and hotel work
- We never seal over old sealant
- More than 20 years in sealant work
- Arbo and Everbuild products
Your questions about external mastic in Crosswater
Can you do external mastic in Crosswater?
Yes, Crosswater 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, and we will give you a clear price.
Can you help a landlord with a rental near Farnham station?
Yes. We work for landlords and agents as well as householders. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Can you seal joints between two different materials?
Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. The sealant is matched to both sides.
How long will you be here?
That depends on how much there is to do, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We’ll tell you when we quote.
Can you reach joints on upper floors?
That depends on the building and the joints. We work on joints that can be reached safely. Tell us about the building and we will confirm what access is needed.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Is it OK to fill a movement joint with cement?
No, not if it’s a movement joint. Pointing it stops it working. A flexible sealant is the right fill.
Will the new joint stand out?
We choose a sealant colour to suit the brick, stone or render. Exterior sealants come in a good range of colours.
What affects the quote in Crosswater
Some jobs are bigger than they look, and some smaller. The main factors:
- Working hours on commercial sites
- How easy the joints are to reach
- The number and length of the joints
- The number of rooms or windows
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or email us and we will talk you through it.
What to tell us for a quote
To help us quote quickly, please include:
- Roughly how big the job is
- A few pictures by email, if you can
- The type of property
- How we’d reach the joints
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.
Different surfaces, different methods
Render joints
Render has movement joints and stop beads that need sealing. We reseal them with a flexible exterior sealant that suits the render colour.
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.