Oxfordshire · England
Lower Assendon External Mastic
External mastic across Lower Assendon and nearby, with old sealant always removed completely and a 12-month guarantee.
- Moss and dirt in joints with no sealant left
- Joints with sealant missing in places
- Damp patches traced to an open external joint
How we quote for external mastic
We don’t publish a price list, because jobs vary so much. What we look at:
- Whether there’s mould to deal with
- The number and length of the joints
- Which sealant suits the joint
- The number of rooms or windows
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. We’ll give you a clear price for the lot.
Asking for a quote
Photos by email are helpful but not essential. Please mention:
- The problem you’ve noticed
- How many joints, rooms or windows are involved
- A few pictures by email, if you can
- How we’d reach the joints
For external mastic in Lower Assendon, call 0345 464 0079 or email us. Tell us what the problem is and where, and we’ll agree the price before any work begins.
How we handle external mastic in Lower Assendon
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We strip the joint back and start again. If you’re dealing with sealant that has lost its bond to the brick or render and weathered mastic that no longer stretches, we can help, on render & cladding joints, façade panels and concrete & block alike.
External sealant needs dry, clean surfaces, so work around Lower Assendon is planned for dry weather. Tell us about access to all sides of the building, including outbuildings and garages.
Whatever the size of the job, you get the same 12-month guarantee.
- Location
- Lower Assendon (RG9)
- Wider area
- Oxfordshire
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
External mastic in Lower Assendon: local notes
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. With historic houses such as Greys Court (about 1.6 miles south-west) nearby, there’s older building stock in the area around Lower Assendon as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
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. In the older streets around Church of St Anne, older walls, gutters and the joints where extensions meet them need a flexible sealant. For site and facilities teams at buildings such as Rupert House School, larger buildings have long runs of movement joint that eventually need resealing.
Lower Assendon is about 6 miles north of Caversham, in Oxfordshire. Homes, rented property, offices and hotels in Lower Assendon can book us for external mastic, old or new, large or small. The work is guaranteed for a year. Lower Assendon is one of 443 towns and villages in Oxfordshire where we work for external mastic. We also work in Reading, about 8 miles from Lower Assendon.
Here we cover the RG9 postcode area for external mastic. That includes homes and businesses on Old Bix Road and Fair Mile and the roads around them. Neighbouring places we cover for external mastic include Middle Assendon (1 mile north-west), Bix (1 mile north-west), Fawley Bottom (1 mile north), Fawley (1 mile north-east) and Henley-on-Thames (2 miles south-east). Larger places within reach include Didcot (14 miles west), Thame (13 miles north), Benson (9 miles north-west), Chinnor (10 miles north), Tilehurst (8 miles south-west) and Wallingford (9 miles west).
What’s near Lower Assendon
In Lower Assendon, that means homes and buildings near Golden Ball Public House, Fawley Court and Temple Island and Gillotts School, among other places. Lower Assendon’s nearest station is Henley-On-Thames station, roughly 1.9 miles south-east. Nearby you’ll also find Frazer Nash Archives (2.2 miles south-east). Green spaces nearby include Warburg Nature Reserve.
Why deal with it now?
Running new sealant over the old bead rarely lasts. New sealant doesn’t bond well to old, weathered sealant, so the old joint is cut out fully first. Older cottages and farmhouses around Lower Assendon can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs, plus any working-time requirements on site. Call for a quick quote and we will go through it with you.
Why choose Mr Mastic in Lower Assendon
- 180+ five-star Google reviews
- ARBOMaster approved applicator
- Homes, businesses and hotels
- Over 20 years’ experience
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
How to look after the new joints
After the cure time, these simple habits help:
- Walk round the building once a year and look at the joints
- Act on the first splits you see
- Clear growth from the base of walls and joints
- Leave the joints unpainted unless we’ve said otherwise
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Act while the splits are small. At that stage it’s a simple cut out and reseal.
Nearby places to Lower Assendon
What else we do in Lower Assendon
For landlords and businesses
Letting agents often deal with us directly. Tell us the address, the job and how access works.
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
Questions from Lower Assendon
Do you cover Lower Assendon for external mastic?
Yes, Lower Assendon is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Do you cover smaller places like Lower Assendon?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Is there a guarantee?
Yes: twelve months. If anything is not right with the work within the year, let us know and we’ll sort it.
Which products do you use?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice, and we will tell you what we are using.
Do you use backing rod?
The foam is closed-cell backing rod. It stops the sealant going in too deep and bonding to three sides so it can flex with the joint.
Can you reach joints on upper floors?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we’ll confirm what’s needed.
What is a movement joint?
A vertical gap in a long brick wall is normally a movement joint. It gives the wall room to move.
When will the joints need doing again?
There’s no fixed answer: sunny, exposed elevations and busy joints wear faster. Check them each year and reseal when they split or harden. Every job carries our one-year guarantee.
What the job involves on each surface
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so the sealant in it must stay soft and stretchy.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. A flexible sealant bridges the two so neither cracks the other.
How it works
On the day, we start by going over the job with you, so there are no surprises. We protect the surfaces around the joints before we start. The work usually takes anything from a few hours to several days, depending on the building. Somewhere like Lower Assendon needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- 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.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Before we arrive
- On commercial sites, let us know about site rules
- Mention any leaks or damp you’ve noticed
- Tell us if parking is tricky
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.