Hampshire · England
External Mastic in Alton
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Alton. Fully insured, ARBOMaster approved and guaranteed for a year.
- Hard, crazed mastic that has stopped moving
- Leaking joints around cladding and façade panels
- Plants rooting in failed movement joints
How we handle external mastic in Alton
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Porous or awkward surfaces are primed where the sealant needs it, and we don’t skip that step. If you have movement joints filled with mortar instead of sealant and water getting into walls through failed joints, we can put it right, on render & cladding joints, concrete & block and copings & trims alike.
Extensions are a common sight on houses around Alton, and the line where an extension meets the original house is a common leak point. Getting the joint depth right matters as much as the sealant itself.
A 12-month guarantee comes as standard.
- Where
- Alton (GU34)
- Region
- Hampshire
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
At the end, we look at the finished work together and explain the cure time. The work normally takes anything from a few hours to several days, depending on the building, depending on the size of the job. For a job in Alton, we need access to where the work is and somewhere nearby to park. If the job is outside, mention gates, side access and anything above ground floor.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Try not to wet indoor joints just before the visit
- On commercial sites, let us know about site rules
- Let us know if you’ve seen damp or leaks
Getting a quote
Getting a quote is simple: tell us what needs doing and where and its rough size. A few photos by email make the job easier to understand, and we will come back to you with a quote.
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Alton questions
Is there a guarantee on external mastic in Alton?
All our work, in Alton and everywhere else, comes with a 12-month guarantee. We are fully insured, and an ARBOMaster approved applicator.
Is Alton in your area for external mastic?
Yes, Alton is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or drop us an email and tell us what needs doing, and we will send you a clear quote.
Are you fully insured?
Yes, we’re fully insured.
Can you match the colour of my brickwork?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We choose the closest to your brick or render.
Can you do several jobs on one visit?
Yes. More than one area can go on one quote.
How do I get a quote for external mastic in Alton?
We don’t publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. You’ll get a clear quote before we start.
Can you reach joints on upper floors?
It depends on the height and the site. Low-level joints are straightforward; for higher ones, send details and we will confirm the access.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned before resealing.
Aftercare tips
Aftercare is simple, and it makes a real difference:
- Tell anyone working on the walls about the movement joints
- Act on the first splits you see
- Do not let climbing plants root in the sealant
- Keep water from gutters off the wall
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They must stay as flexible joints, never rendered or pointed over.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
Places near Alton
More services for Alton
Walls and rooflines in Alton
With historic houses such as Bentworth Hall (about 3.2 miles west) nearby, there’s older building stock in the area around Alton as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
In the older streets around Church of St Lawrence, the joints between older walls, newer extensions and the roofline need a sealant that can move. Rented homes near Alton station change hands often, and split movement joints are easy to miss on a rental until damp shows inside. For site and facilities teams at buildings such as Saint Lawrence Church of England Primary School, larger buildings have long runs of movement joint that eventually need resealing.
Alton is about 10 miles south-east of Basingstoke, in Hampshire. Jobs in Alton get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. 683 places in Hampshire are on our list. Our Reading page covers work nearby.
Here we cover the GU34 postcode area for external mastic. That includes homes and businesses on High Street, Station Road and Goswell Square. Alton is on the A339 and B3004, so it’s easy for us to get to. Nearby, we also carry out external mastic in Chawton (1 mile south-west), Holybourne (2 miles north-east), Neatham (2 miles north-east), East Worldham (2 miles south-east) and Golden Pot (2 miles north). We also work in nearby towns such as Basingstoke (10 miles north-west), Farnborough (13 miles north-east), Fleet (10 miles north-east), Aldershot (11 miles north-east), Petersfield (10 miles south) and Yateley (14 miles north-east).
Near you in Alton
We work in homes and buildings around Amery Hill School, Treloar School and The 'Baker's Arms' Public House, among other places. There’s a railway station in Alton itself: Alton station. Nearby you’ll also find Allen Gallery (under half a mile east) and Alton Community Hospital (0.9 miles south-west). Green spaces nearby include Holybourne Hill.
What the job involves on each surface
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. We reseal them with an exterior sealant suited to the material.
Render joints
Render is weaker at the surface than brick, so a sealant that stretches easily protects the edges. We prime where the product needs it.
Landlord and commercial work in Alton
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Letting agents often deal with us directly. Tell us the address, the job and how access works.
When something else is needed
New sealant cannot fix everything, and we will tell you before we start. It will not solve:
- Rising or penetrating damp from elsewhere in the wall
- Cracks in the bricks or render themselves, away from the joints
- Cutting new joints into brickwork, which is building work rather than sealant work
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think.
Joints and surfaces we work on
- Brickwork movement joints
- Copings & trims
- Render & cladding joints
- Façade panels
- Concrete & block
- Joints between brick and frames
What affects the quote in Alton
Some jobs are bigger than they look, and some smaller. The main factors:
- How many areas need sealing
- The size of the job
- Whether there’s mould to deal with
- Working hours on commercial sites
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, phone 0345 464 0079 or send us an email and we will give you an honest view and a quote.
What to tell us for a quote
Photos help, but a description is a good start. Try to tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
- If someone has resealed it before
- How many joints, rooms or windows are involved
We don’t publish a price list. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or send us an email.
DIY sealant or a professional job?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.