Hertfordshire · England
External & façade joints in Long Marston, Hertfordshire
External mastic in Long Marston from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Failed seals between different materials
- Moss and dirt in joints with no sealant left
- Failed sealant between panels on a façade
External mastic in Long Marston
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a colour to suit. We work on brickwork movement joints, copings & trims and façade panels, and people most often call us about plants rooting in failed movement joints and joints pointed up with cement by mistake.
Older homes in small places like Long Marston may be stone, brick or timber-framed, often with later extensions. Where one material meets another is where water generally gets in, and they need the right sealant at the right depth.
All of our work is guaranteed for twelve months.
- Place
- Long Marston (HP23)
- Region
- Hertfordshire
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we will give you a quote.
For anyone letting property in or around Long Marston, several properties can go on one quote. Send us the addresses and the work at each.
Your questions about external mastic in Long Marston
Do you work for landlords with property near Cheddington station?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or send us an email and tell us about the property, and we’ll give you a clear quote.
Can you do external mastic in Long Marston?
Yes. Our work covers London and the South East, and Long Marston is part of that. Just ring 0345 464 0079 or send us an email with a few details of the job.
How long does external mastic take?
Typically it takes a few hours for a handful of joints, longer for a whole elevation. Larger jobs naturally take longer, and we will tell you how long to expect.
Do you do commercial work?
Yes. We work in offices, washrooms, hotels and other commercial premises, as well as homes. Working times can be discussed when we quote.
Can you do several jobs on one visit?
Yes, we can. Several rooms, windows or areas can go on one quote.
Is it messy?
We keep the work tidy. Nearby surfaces are protected, and we clear up when we’re done.
Can you seal joints between two different materials?
Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
How long should I leave it?
Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint.
How to look after the new joints
Looking after new joints is easy:
- Have failed joints looked at early
- Do not let climbing plants root in the sealant
- Ask before painting over external sealant
- Make sure movement joints are not pointed over
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
A joint that has stopped moving pushes the movement elsewhere, generally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
The process
We keep the work tidy and contained to the area we are working on, so you can get on with your day. The job usually takes a few hours for a handful of joints, longer for a whole elevation. In a small place like Long Marston, access is usually the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- Move anything stored near the joints
- Tell us about any water getting in
- Mention any tricky access
Get a quote
For external mastic in Long Marston, phone 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
Advice
Why it’s worth doing now in Long Marston
Sealing over the top of old mastic does not hold for long. The new layer can’t bond properly to old, weathered material, so the old joint is cut out fully first. Older cottages and farmhouses around Long Marston can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
Why Long Marston customers choose us
- Any old sealant cut out fully, not covered over
- We’re fully insured
- Anti-fungal silicone where joints get wet
- ARBOMaster approved applicator
Can I do it myself?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
External mastic in Long Marston: local notes
Historic houses like Ascott House (about 4.3 miles north) are a reminder that the area around Long Marston 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. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For landlords with property near Cheddington station, split movement joints are easy to miss on a rental until damp shows inside. For site and facilities teams at buildings such as Long Marston VA Church of England Primary School, its movement joints, gutters and trims need looking after like any other building’s. If you live in an older home near Church of All Saints (Church of England), the joints between older walls, newer extensions and the roofline need a sealant that can move.
Long Marston is about 5 miles east of Aylesbury, in Hertfordshire. Anywhere in HP23, our applicators can take on external mastic. 381 places in Hertfordshire are on our list, from the larger towns to small villages. For nearby work, see our Oxford page, about 23 miles away.
Every address in HP23 is within our area for external mastic. Streets in the area include Station Road, Chapel Lane and Bromley, and we cover them all. If you are just outside Long Marston, we cover Astrope (1 mile south), Puttenham (1 mile south-west), Buckland (2 miles south), Aston Clinton (2 miles south-west) and Wingrave (3 miles north-west). Within a short drive, we also cover Hemel Hempstead (12 miles south-east), Harpenden (15 miles east), Berkhamsted (7 miles south-east), Tring (3 miles south-east), Chorleywood (15 miles south-east) and Grovehill (11 miles south-east).
What’s near Long Marston
Long Marston’s nearest station is Cheddington station, about 2.4 miles north-east. Nearby you’ll also find Tindal Centre (4.4 miles west) and Pitstone Green Museum (2.6 miles east). Not far away are Ivinghoe Beacon and College Lake nature reserve.
How the job changes by surface
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. Each is resealed with a weatherproof, flexible sealant.
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it. Tell us what the building has when you get in touch.
Also in Long Marston
What sealant work can’t fix
It helps to know what we can’t do too:
- Damp that isn’t coming from the joint
- Loose or hollow render, which needs re-rendering
- Walls that need new movement joints cut into them
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly.
Where we work in Long Marston
- Joints between brick and frames
- Concrete & block
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Façade panels