Buckinghamshire · England
External Mastic in Granborough
Sealing brickwork movement joints, render, cladding and façade joints in Granborough, with a 12-month guarantee on every job. Ask us for a quote.
- Weathered mastic that no longer stretches
- Plants rooting in failed movement joints
- Cracked joints where brick meets render or frames
About our external mastic in Granborough
A movement joint is a deliberate break that lets a wall expand and contract. 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 concrete & block, copings & trims and joints between brick and frames, and the jobs we see most are hard, crazed mastic that has stopped moving and sealant pulling away from one side of the joint.
In a village or hamlet like Granborough, older cottages and farm buildings often stand in the open, so walls and rooflines take the full force of wind and rain. Joints on those walls need a sealant that moves with the building and stays in place.
Each job carries a 12-month guarantee, whatever its size.
- Location
- Granborough (MK18)
- Wider area
- Buckinghamshire
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What we can’t put right
Before you book, it’s worth knowing the limits too:
- Movement that’s more than a sealant joint can take
- Failed render or damaged cladding panels
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If you are not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before you book.
What we seal
- Façade panels
- Render & cladding joints
- Joints between brick and frames
- Concrete & block
- Copings & trims
- Brickwork movement joints
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together, and we are fully insured for the work.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Check the sealant is paintable before painting near it
- Fix overflowing gutters above sealed joints
- Walk round the building once a year and look at the joints
- Tell anyone working on the walls about the movement joints
Do not let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
Leave a failed movement joint and water keeps getting into the wall. Over time it can mean damp inside, stained render or frost-damaged brick.
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
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.
What we do, step by step
Once we are on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours to a few days, depending on the length of joint and the access. In a small place like Granborough, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- 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.
Before we arrive
- Clear items away from the joints we’re working on
- Let us know about earlier repairs to the joints
- Try not to wet indoor joints just before the visit
Get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.
Advice
What affects the cost of external mastic
For a quick quote, just ask. The main things that affect it are:
- Any working-time requirements on site
- The number of rooms or windows
- How easy the joints are to reach
- Which sealant suits the joint
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are unsure, call 0345 464 0079 or send us an email for an honest opinion and a quote.
What we need to know
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
It all starts with a short chat. Describe the problem, the location and the size of the job. When it suits you, ring 0345 464 0079 or send us an email.
Towns and villages near Granborough
Also in Granborough
What external mastic looks like in Granborough
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. Historic houses like Claydon House (about 2.9 miles west) are a reminder that the area around Granborough has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
For an older house near a landmark such as Church of St John the Baptist, an extension built onto an older house moves differently, and the joint between them takes the strain.
Granborough is about 7 miles south-east of Buckingham, in Buckinghamshire. If you need external mastic in Granborough, please call 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Buckinghamshire, Granborough included. 263 places in Buckinghamshire are on our list, large and small. We also work in Oxford, about 19 miles from Granborough.
We work across MK18 for external mastic. We cover properties on Marks Orchard, Winslow Road and Sovereign Close. Neighbouring places we cover for external mastic include Winslow (2 miles north), Swanbourne (3 miles north-east), Dunton (3 miles east), Great Horwood (4 miles north) and Mursley (4 miles north-east). We also work in nearby towns such as Aylesbury (8 miles south-east), Buckingham (7 miles north-west), Elmhurst (7 miles south-east), Southcourt (9 miles south), Princes Risborough (14 miles south) and Haydon Hill (7 miles south).
Near you in Granborough
Locally, jobs take us to homes and businesses close to The Crown pub and the streets around them. Well-known places in the area include Bolbec Castle (3.4 miles south-east).
Questions from Granborough
Is Granborough in your area for external mastic?
Yes. Our work covers London and the South East, and Granborough is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Do you cover smaller places like Granborough?
Yes, Granborough is covered. Our work covers London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
How long does the job take?
It depends on the size of the job, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We will give you a better idea when we quote.
Do the sealants smell?
Possibly a little. It fades as the sealant cures, and ventilation helps.
How much does external mastic cost in Granborough?
It depends on the job, so we quote each one individually. For a quick quote, ring 0345 464 0079 or drop us an email and tell us what needs doing and where.
Can a movement joint be filled with mortar?
No. Mortar locks the joint solid, so the movement cracks the wall elsewhere. It needs a flexible sealant over backing rod.
Do you take out the old sealant first?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Is it worth trying it myself?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs.
Signs you need external mastic in Granborough
Some movement joints have been pointed up with mortar by mistake. The joint cannot move, so the wall cracks somewhere else instead.
If you can see any of these, it’s time to have the joints looked at:
- Sealant pulling away from one side of the joint
- Joints pointed up with cement by mistake
- Moss and dirt in joints with no sealant left
- Cracked joints where brick meets render or frames
For site and facilities teams at buildings such as Sir Thomas Fremantle School, its movement joints, gutters and trims need looking after like any other building’s.
What your quote should include
- How hidden problems are handled
- How much experience the applicator has
- Is VAT in the price?
- When the joint can take water or movement