Hampshire · England
Bagmore External Mastic
External mastic across Bagmore and nearby, with old sealant always removed completely and a 12-month guarantee.
- Moss and dirt in joints with no sealant left
- Water getting into walls through failed joints
- Rigid filler in a joint that should flex
How we handle external mastic in Bagmore
On houses, flats and commercial buildings across Bagmore, we reseal joints in brickwork, render, cladding and façade panels. Every joint gets the same careful preparation: clean joint faces and the right depth. We work on façade panels, copings & trims and joints between brick and frames, and people most often call us about weeds or debris growing in open joints and failed seals between different materials.
Around Bagmore, older buildings can be stone, brick or timber-framed, many with extensions added later. Where one material meets another is where water generally gets in.
All of our work is guaranteed for twelve months, in Bagmore and everywhere else we cover.
- Place
- Bagmore (RG25)
- Wider area
- Hampshire
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
How we quote for external mastic
Your quote is based on your job. We look at:
- Mould in or behind the old joints
- The product the joint needs
- Working hours on commercial sites
- How much old sealant there is and how hard it is to remove
What it costs depends on the amount of work, how hard the old material is to remove and access to the work. We give a clear quote before work begins.
Asking for a quote
There’s no need for technical detail. It helps if you can tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- The type of property
- Access, such as stairs, a lift or height
- Any previous sealing or DIY work
If you are in Bagmore and need external mastic, phone 0345 464 0079 or send us an email. Tell us what the problem is and where, and we’ll agree the price before any work begins.
Your questions about external mastic in Bagmore
Can you do external mastic in Bagmore?
Yes, Bagmore is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
I let a flat near Alton station. Can you help?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before any work starts.
Does someone need to be in?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we will agree access with you when we book.
Can you do several jobs on one visit?
Yes. Just list everything you need and you’ll get one quote.
How long should I leave it?
It depends on the product. We tell you how long to leave it before we go.
Will there be a smell?
Sometimes, a little. It fades as the sealant cures.
Can you seal joints between render and window frames?
Yes. Joints between dissimilar materials are a big part of external work. The sealant is chosen to bond to both sides with primer where required.
Can I do 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.
Walls and rooflines in Bagmore
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 Hall Place (about 3 miles south) are a reminder that the area around Bagmore has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
If you live in an older home near Church of St. Mary, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Bagmore is about 5 miles north-west of Alton, in Hampshire. Across the RG25 area, our applicators can take on external mastic. Bagmore is one of 683 places in Hampshire we cover. You can also see our page for Reading, about 18 miles away.
Every address in RG25 is covered for external mastic. If you’re just outside Bagmore, we cover Southrope (1 mile east), Burkham (1 mile south-west), Shalden Green (2 miles east), Bradley (3 miles south-west) and Bentworth (3 miles south). Within a short drive, we also cover Basingstoke (5 miles north-west), Winchester (15 miles south-west), Farnborough (14 miles north-east), Fleet (11 miles north-east), Aldershot (13 miles east) and Alton (5 miles south-east).
Landmarks near Bagmore
The nearest railway station is Alton station, about 4.9 miles south-east. Other landmarks nearby include Alton Community Hospital (4.9 miles south-east) and Gliding Heritage Centre (1.6 miles south-east). The countryside around Bagmore includes Farleigh Hill.
The process
Once we are on site, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. Most jobs then take anything from a few hours to several days, depending on the building. For a village or hamlet like Bagmore, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. 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.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
How to prepare
- Mention any leaks or damp you’ve noticed
- Mention any sign-in or site rules at work premises
- Tell us if parking is tricky
Ask for a quote
Asking for a quote is easy: tell us what needs doing and where. Photos by email help us understand the job, and we will take it from there.
Advice
Common problems we fix in Bagmore
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint can’t move, so the wall cracks somewhere else instead.
The problems people usually mention when they call are:
- Brick movement joints where the sealant has split
- Cracked joints where brick meets render or frames
- Leaking joints around cladding and façade panels
- Water getting into walls through failed joints
Letting a property close to Alton station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before you book
- How long the guarantee is
- Whether they’re fully insured
- What happens if they find a problem under the old sealant
- Whether all the old sealant comes out first
What we cannot put right
Before you book, it’s worth knowing the limits too:
- Subsidence or other structural problems
- Adding movement joints to masonry that has none
- Cracks in the bricks or render themselves, away from the joints
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly before booking.
Joints and surfaces we work on
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Copings & trims
- Concrete & block
- Joints between brick and frames
Aftercare tips
Looking after new joints is easy:
- Walk round the building once a year and look at the joints
- Deal with leaking gutters that soak the joints below
- Tell anyone working on the walls about the movement joints
- Leave the joints unpainted unless we have said otherwise
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years.
Why it’s worth doing now in Bagmore
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. Where a wall is exposed, as many are in small places like Bagmore, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, ring 0345 464 0079 or email us for an honest opinion and a quote.
Why choose Mr Mastic in Bagmore
- Domestic, commercial and hotel work
- Old sealant always removed completely
- Colour picked to suit the job
- 20+ years of sealant experience
Read what affects the cost and our reviews.
For landlords and businesses
If you manage several properties in or around Bagmore, several properties can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.