Oxfordshire · England
External Mastic in Harpsden Bottom
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Harpsden Bottom and across Oxfordshire. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Rigid filler in a joint that should flex
- Hard, crazed mastic that has stopped moving
- Cracked joints where brick meets render or frames
External mastic in Harpsden Bottom
A movement joint is only as good as its depth. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, leaving it bonded to two faces so it can move with the wall. If you have gaps where render, brick and frames meet and rain getting behind render or cladding at a joint, we can help, on joints between brick and frames, façade panels and brickwork movement joints alike.
In a village or hamlet like Harpsden Bottom, 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.
The work is covered for a year after we finish. If anything isn’t right with it, phone 0345 464 0079 or drop us an email.
- Location
- Harpsden Bottom (RG9)
- Wider area
- Oxfordshire
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
For landlords and businesses
If you manage several properties in or around Harpsden Bottom, several properties can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
We also work for property managers and facilities teams. We can quote a run of properties together, and we’re fully insured for the work.
Looking after it afterwards
After the cure time, these simple habits help:
- Deal with leaking gutters that soak the joints below
- Wash walls gently around the sealant
- Walk round the building once a year and look at the joints
- Ask before painting over external sealant
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They should be kept open and resealed, not filled.
An open movement joint lets rain into the wall every time it pours. Over time it can mean damp inside, stained render or frost-damaged brick.
Harpsden Bottom: your questions answered
Do you work for landlords with property near Henley-On-Thames station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will send you a clear quote.
Can you do external mastic in Harpsden Bottom?
Yes, Harpsden Bottom is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
Do you remove the old sealant?
Yes, always, and completely. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose and can lead to cracking. We will reseal it with a flexible sealant.
Can you quote for more than one area?
Yes. Just list everything you need.
Do you hold any approvals?
Yes. We’re approved under the ARBOMaster scheme.
Where are you based?
Mr Mastic is based in Crawley. We cover Harpsden Bottom and the rest of Oxfordshire.
Can new sealant go over the old?
No, because it fails. We remove every bit of old sealant first, so the new sealant bonds properly.
The process
All our tools and materials come with us in the van. Once we’ve agreed what’s being done, we protect the area and start. It normally takes anything from a few hours to several days, depending on the building. Somewhere as small as Harpsden Bottom, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We look at every joint and agree a colour to suit the wall.
- 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.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Where the joints are inside, avoid wetting them before we arrive
- Keep children and pets away from the work area
- Let us know about stairs, lifts or work at height
How to get a quote
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.
Advice
DIY sealant or a professional job?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Different surfaces, different methods
Render joints
Render is weaker at the surface than brick, so a sealant that stretches easily protects the edges. Priming is done where the sealant calls for it.
Cladding and façade panels
Panels heat up and cool down quickly, so the joint sealant has to cope with frequent movement. We choose the product to suit.
Also near Harpsden Bottom
Other services in Harpsden Bottom
What external mastic looks like in Harpsden Bottom
Historic houses like Greys Court (about 2.3 miles north-west) are a reminder that the area around Harpsden Bottom 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. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you live in an older home near Church of St Margaret, old and new materials meet at the roofline and walls, which is where sealant earns its keep. If you let a flat or house near Henley-On-Thames station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. For site and facilities teams at buildings such as Gillotts School, larger buildings have long runs of movement joint that eventually need resealing.
Harpsden Bottom is about 4 miles north-east of Caversham, in Oxfordshire. We carry out external mastic for homes and businesses in Harpsden Bottom, as part of our work across Oxfordshire. 443 places in Oxfordshire are on our list, from the larger towns to small villages. You can also see our page for Reading, about 6 miles away.
Here we cover the RG9 postcode area for external mastic. Other places close to Harpsden Bottom include Harpsden (1 mile east), Henley-on-Thames (1 mile north-east), Shiplake Cross (2 miles south-east), Binfield Heath (2 miles south) and Lower Assendon (2 miles north). Further out, we also cover Didcot (15 miles north-west), Benson (11 miles north-west), Chinnor (12 miles north), Tilehurst (7 miles south-west), Wallingford (11 miles north-west) and Little Heath (7 miles south-west).
Near you in Harpsden Bottom
Around Harpsden Bottom, our work takes us to homes and buildings near Rupert House School, Saracen's Head pub and Valley Road School and the streets around them. Harpsden Bottom’s nearest station is Henley-On-Thames station, about 1.1 miles north-east of the centre. Other landmarks nearby include Royal Berkshire Hospital (5.3 miles south) and Frazer Nash Archives (1 mile north-east). Open spaces near Harpsden Bottom include Hurley Chalk Pit and Sonning Hill.
What sealant work cannot fix
Honest advice matters more to us than a booking, so here’s what new sealant will not do:
- Movement that is more than a sealant joint can take
- Cracking across the wall rather than at a joint
- Rising or penetrating damp from elsewhere in the wall
If in doubt, ring 0345 464 0079 or email us and we will say what we think.
Surfaces we seal
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Façade panels
- Render & cladding joints
Why act early in Harpsden Bottom
Sealing over the top of old mastic does not hold for long. New sealant doesn’t bond well to old, weathered sealant, so the old joint is cut out fully first. In a small place like Harpsden Bottom, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why Harpsden Bottom clients choose us
- Fully insured
- Experience in homes, commercial sites and hotels
- Arbo and Everbuild products
- We agree the colour with you first
Take a look at what affects the cost or our reviews.