Wokingham · England
Crowthorne External Mastic
Movement joints in Crowthorne need attention? We remove the old material, prepare the joints and seal them properly, with a 12-month guarantee.
- Sealant that has lost its bond to the brick or render
- Brick movement joints where the sealant has split
- Hard, crazed mastic that has stopped moving
External mastic for homes and businesses in Crowthorne
A movement joint is a deliberate break that lets a wall expand and contract. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. Common call-outs are for joints with sealant missing in places and water getting into walls through failed joints, on façade panels, joints between brick and frames and copings & trims.
Extensions are a common sight on houses around Crowthorne, and the joint where new wall meets old is a classic place for water to get in. Sealing it properly means the right joint depth and a flexible sealant, not a quick bead.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- Crowthorne (RG45, RG40)
- Region
- Wokingham
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
When it isn’t the sealant
Sealant isn’t the answer to every problem, and we’ll tell you before work begins. Sealant will not put right:
- Walls that need new movement joints cut into them
- Render that’s blown, hollow or coming away
- Rising or penetrating damp from elsewhere in the wall
If you’re not sure, just call 0345 464 0079 or send us an email and we’ll give you a straight answer before booking.
Joints and surfaces we work on
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block
- Façade panels
Quotes for external mastic in Crowthorne
We quote each job individually. These are the things that affect it:
- The product the joint needs
- The number and length of the joints
- The old material and how stubborn it is
- Mould in or behind the old joints
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Call for a quick quote and we will explain what it covers.
Asking for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Whether it has been sealed before
- The type of property
- Where the job is, and your postcode
- Pictures of the joints, sent by email
Getting a quote is simple: let us know the job and the location and its rough size. Photos by email help us understand the job, and we will come back to you with a quote.
Crowthorne questions
Is external mastic in Crowthorne guaranteed?
Every job comes with our 12-month guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Do you work for landlords with property near Crowthorne station?
Yes. We work for letting agents and landlords as well as householders. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
How often do external joints need resealing?
That varies with the weather the wall faces, how much it moves and the sealant used. Sealant is a maintenance item, so check the joints once a year and renew it when it starts to fail.
Do I have to be there?
That depends on where the joints are. For work indoors, someone needs to let us in.
Where is Mr Mastic based?
We are a Crawley-based firm. We work across South East England, London and Scotland.
What is a movement joint?
It’s a deliberate gap that lets the wall expand and contract without cracking. It’s sealed with a flexible sealant, not mortar.
Is there any odour?
That depends on the sealant. Some smell for a while, some hardly at all, and any smell fades as they cure.
Are you ARBOMaster approved?
Yes. We’re approved under the ARBOMaster scheme, the approved applicator scheme for Arbo sealants.
Nearby places to Crowthorne
Also in Crowthorne
What we’re called out for in Crowthorne
The wrong product in a moving joint is a classic cause. A high-modulus or general-purpose sealant can be too rigid for a busy joint, so it pulls away from the edges.
Common reasons people contact us are:
- Weeds or debris growing in open joints
- Old sealant gone brittle and cracked
- Rigid filler in a joint that should flex
- Movement joints with cracked, split or missing sealant
Managing a site like Crowthorne Church of England Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
Comparing quotes
- What the quote includes, VAT included or not
- What preparation is included
- Is the old sealant removed completely?
- Whether the sealant suits the joint
What the job involves on each surface
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap and keep the sealant to the right depth.
Render joints
Render has movement joints and stop beads that need sealing. They’re resealed in a sealant that suits the render.
For landlords and businesses
Housing providers, facilities teams and property managers book us too in Crowthorne and across Wokingham. We can quote a run of properties together.
From a single let to a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Looking after it afterwards
So the new joints stay in good condition:
- Fix overflowing gutters above sealed joints
- Leave the joints unpainted unless we’ve said otherwise
- Show decorators and builders where the movement joints are
- Walk round the building once a year and look at the joints
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Gaps, plants or missing sealant in a joint are worth getting looked at. Earlier resealing means a smaller job and a better result.
The process
There is not much for you to do on the day. Point us to the joints and we’ll get on with it. The job generally takes anything from a few hours to several days, depending on the building from start to finish. Parking in a town like Crowthorne is usually straightforward, but tell us if there’s a driveway or any restrictions, and let us know if the work is upstairs, in a flat or up high outside.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Let us know about stairs, lifts or work at height
- For business premises, tell us about site rules or sign-in
- Mention any leaks or damp you’ve noticed
How to get a quote
To get a quote, ring 0345 464 0079 or send us an email with the location and a short description of the problem. We will give you a clear price before any work starts.
Advice
External mastic in Crowthorne: local notes
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For an older house near a landmark such as Crowthorne Methodist Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. Rented homes near Crowthorne station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Crowthorne is about 3 miles south-west of Bracknell, in Wokingham. If you need external mastic in Crowthorne, please call 0345 464 0079 or email us for a quick quote. We are based in Crawley and cover Wokingham, Crowthorne included. Our Wokingham coverage runs to 35 places, Crowthorne among them. There’s also a page for Reading, about 9 miles away.
Our applicators cover all of RG45 and RG40 for external mastic and the streets around it. You’ll find streets such as Church Road East, Church Road West and High Street, all of which we cover. Crowthorne sits on or near the A321 and B3348. Neighbouring places we cover for external mastic include Owlsmoor (1 mile south-east), Home Farm (1 mile north-east), Wooden Hill (2 miles north-east), Sandhurst (2 miles south) and Hanworth (2 miles north-east). Larger places within reach include Reading (9 miles north-west), Wokingham (3 miles north-west), Woodley (7 miles north-west), Earley (7 miles north-west), Lower Earley (6 miles north-west) and Winnersh (5 miles north-west). Being one of Wokingham’s larger places, Crowthorne has homes, rented property and businesses of every kind.
Landmarks near Crowthorne
Typical jobs here are in homes near King Edward VI Aston School, The Prince pub and Edgbarrow Woods and the streets around them. The closest station to Crowthorne is Crowthorne station, roughly 1 mile south-west. Nearby you’ll also find The Lexicon (3.7 miles north-east) and Pinewood Hospital (0.9 miles north). Open spaces near Crowthorne include Wildmoor Heath and Heath Lake.