Oxfordshire · England
External Mastic in Rowstock
Problem with your movement joints in Rowstock? We cut out the old, prepare the joints and apply the right sealant.
- Joints pointed up with cement by mistake
- Gaps where render, brick and frames meet
- Rain getting behind render or cladding at a joint
Do you need external mastic in Rowstock?
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
People usually contact us when they notice something like this:
- Sealant that has lost its bond to the brick or render
- Weathered mastic that no longer stretches
- Water getting into walls through failed joints
- Leaking joints around cladding and façade panels
Managing a site like Harwell Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
What to look for in a quote
- What product goes in the joint
- Whether VAT is included
- What the cure time is
- Are they insured?
How we handle external mastic in Rowstock
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible exterior sealant takes up that movement. Typical jobs include moss and dirt in joints with no sealant left and rain getting behind render or cladding at a joint, across brickwork movement joints, render & cladding joints and façade panels.
Around Rowstock, older buildings can be stone, brick or timber-framed, many with extensions added later. The joints where those materials meet are the weak points.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Place
- Rowstock (OX11)
- Wider area
- Oxfordshire
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
The process
There’s no need to move everything out before we come, only the area right around the joints. Everything nearby is protected, and the work takes a few hours to a few days, depending on the length of joint and the access in most cases. In a small place like Rowstock, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Plan for the work area to be out of bounds to pets and children
- Mention any parking rules near the property
- Tell us about access, such as stairs, a lift or high-level joints
Ask for a quote
Getting a quote is simple: let us know the job and the location. Photos by email help us understand the job, and we’ll come back to you with a quote.
Related advice
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
We also work for property managers and facilities teams. Several sites can be quoted together, and we’re fully insured.
Nearby places to Rowstock
Also in Rowstock
FAQs for Rowstock
Can you do external mastic in Rowstock?
Yes, Rowstock is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job.
Can you help a landlord with a rental near Didcot Parkway station?
Yes, landlords and agents are among the people we work for. Just call 0345 464 0079 or email us with the address and what needs doing, and we will give you a clear price.
When is the sealant fully cured?
Cure times vary by product and the temperature. Before we leave, we will tell you the cure time.
Do you do commercial work?
Yes. We can plan bigger jobs in stages.
Can you reach joints on upper floors?
That depends on the building and the joints. We work on joints that can be reached safely. Give us some details and we will confirm the access.
Is it OK to fill a movement joint with cement?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose, and the wall may crack nearby. A flexible sealant is the right fill.
What should I tell you?
Only a few details: the address or postcode, what’s wrong and any access issues. After that, simply call 0345 464 0079 or email us.
Is it OK to seal over old sealant?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. We remove it all first.
What the job involves on each surface
Render joints
Water behind render can lead to blown patches. Resealing the joints early keeps water out and protects the render itself.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Get split or bare joints resealed while the damage is small
- Point out the joints to other trades
- Avoid pressure-washing directly into sealant joints
- Keep movement joints as flexible joints, not mortar
Make sure anyone working on the wall later knows where the movement joints are. They should be kept open and resealed, not filled.
Once a joint cannot move, the wall finds another way, often as cracks near the joint. Resealing it early helps prevent that.
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
What external mastic looks like in Rowstock
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.
In the older streets around Church of St Matthew, old and new materials meet at the roofline and walls, which is where sealant earns its keep. For landlords with property near Didcot Parkway station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Rowstock is about 3 miles west of Didcot, in Oxfordshire. For external mastic in and around Rowstock, it’s easy to get a quote: please call 0345 464 0079 or email us. We’re based in Crawley and cover Oxfordshire. Our Oxfordshire coverage runs to 443 places, Rowstock among them. We also work in Oxford, around 11 miles away.
Every address in OX11 is within our area for external mastic, from the main roads to the quietest streets. We cover properties on Tudor Walk, Wantage Road and Reading Road. Nearby, we also carry out external mastic in East Hendred (1 mile west), West Hendred (2 miles west), Ardington (3 miles west), East Lockinge (3 miles west) and West Ilsley (4 miles south). Further out, we also cover Oxford (11 miles north), Didcot (3 miles east), Abingdon-on-Thames (5 miles north), Witney (15 miles north-west), Wantage (5 miles west) and Grove (5 miles west).
What’s near Rowstock
Around Rowstock, our work takes us to homes and buildings near Old Chequers pub and UTC Oxfordshire. For rail, the closest station is Didcot Parkway station, about 3 miles east. Well-known places in the area include Atlas Computer Laboratory (1.7 miles south) and Abingdon Community Hospital (4.9 miles north). Not far away are Mowbray Fields and Churn Hill.
What affects the cost of external mastic
Call for a quick quote. The main things that affect it are:
- The number and length of the joints
- The type of sealant required
- Any mould that needs treating
- How many areas need sealing
Leaving a failed joint usually makes the job bigger, not smaller, because water and mould keep working on it. If you are unsure, call 0345 464 0079 or drop us an email and we will give you an honest view and a quote.
What we need to know
Photos by email are helpful but not essential. Try to tell us:
- Where the job is, and your postcode
- Roughly how big the job is
- Whether it has been sealed before
- The problem you’ve noticed
If you are in Rowstock and need external mastic, call 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before any work starts.