Oxfordshire · England
Northway External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Northway and across Oxfordshire. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Moss and dirt in joints with no sealant left
- Joints with sealant missing in places
- Sealant pulling away from one side of the joint
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 helps it last.
Joints between dissimilar materials
Each side of the joint may need its own preparation. Both surfaces are cleaned and primed as the product requires.
External mastic in Northway
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we’ll confirm what access is needed. Typical jobs include failed sealant between panels on a façade and movement joints filled with mortar instead of sealant, across brickwork movement joints, concrete & block and render & cladding joints.
Outbuildings, garages and conservatories around homes in places like Northway add more joints to look after. Leaks generally start at a gutter end, a garage door frame or where an extension meets the house.
We stand behind the work with a one-year guarantee, so you’re covered after we have gone.
- Where
- Northway (OX3)
- Region
- Oxfordshire
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Leave it or put it right?
It often makes sense to reseal all the failing joints on an elevation together. Joints of the same age tend to fail together, and access only has to be arranged once. In a smaller place like Northway, wherever a wall is exposed, a failed outside joint is a real source of damp. Indoors, a failed seal lets water into floors and panels as it would anywhere.
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
Why us?
- Arbo and Everbuild products
- Old sealant always removed completely
- 12-month guarantee on every job
- Homes, businesses and hotels
Read our cost guide or what customers say.
When it isn’t the sealant
In fairness, some problems need a different trade:
- Walls that need new movement joints cut into them
- Loose or hollow render, which needs re-rendering
- Rising or penetrating damp from elsewhere in the wall
If you are not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer before you book.
What we seal
- Brickwork movement joints
- Concrete & block
- Render & cladding joints
- Copings & trims
- Façade panels
- Joints between brick and frames
What affects the cost of external mastic
The quote reflects the job in front of us. We take into account:
- The number and length of the joints
- The type of sealant required
- How much old sealant there is and how hard it is to remove
- When we can work, for business premises
What it costs depends on how much there is to do, how much old material has to come out and how easy the joints are to reach. You’ll have a clear quote before any work starts, so you know where you stand.
Asking for a quote
To make quoting easier, please include:
- What’s wrong with the joints now
- Access, such as stairs, a lift or height
- Where the job is, and your postcode
- How many joints, rooms or windows are involved
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, phone 0345 464 0079 or drop us an email.
Common questions in Northway
Is Northway in your area for external mastic?
Yes. Our work covers London and the South East, and Northway is part of that. You can ring 0345 464 0079 or drop us an email and tell us what needs doing.
Do you work for landlords with property near Oxford station?
Yes, landlords and agents are among the people we work for. You can phone 0345 464 0079 or drop us an email with the details for a clear quote.
Do you work for hotels and businesses?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
Can you match the colour of my brickwork?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before any work starts.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We’ll tell you what we’re using and why.
Do I need to be at home?
We need access to the joints, so we will agree that with you when we book. For inside work, that normally means someone being in.
Is it OK to fill a movement joint with cement?
No, not where the gap is a movement joint. Pointing it stops it working, and the wall may crack nearby. A flexible sealant is the right fill.
Do the sealants smell?
Sometimes, a little. Any smell clears as the sealant cures, and ventilation helps.
How the visit works
When we get to you, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. After that, the work takes anything from a few hours to several days, depending on the building. In a smaller place like Northway, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Move anything stored near the joints
- For indoor joints, keep the area dry beforehand if you can
- Tell us about access, such as stairs, a lift or high-level joints
How to get a quote
Need a quote? Please phone 0345 464 0079 or send us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Read more
Also near Northway
What else we do in Northway
Northway buildings and the weather
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Holywell Manor (about 1.5 miles south-west) nearby, there’s older building stock in the area around Northway as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
Homes close to St Anthony of Padua include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. Managing a site like New Marston Primary School? Then larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Oxford station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Northway is about 1 mile north of Oxford, in Oxfordshire. Anywhere in OX3, we cover external mastic for homes and businesses. Our Oxfordshire coverage runs to 443 places, and Northway is one of them.
Postcode districts we cover here for external mastic: OX3. Streets in the area include Copse Lane, Marsh Lane and Upway Road, and we cover them all. Northway is on the A40, so it’s easy for us to get to. Neighbouring places we cover for external mastic include Headington (1 mile south-east), Marston (1 mile north-west), New Marston (1 mile south-west), Headington Hill (1 mile south) and Headington Quarry (1 mile south-east). Within a short drive, we also cover Didcot (11 miles south), Bicester (9 miles north), Abingdon-on-Thames (7 miles south), Witney (12 miles west), Thame (11 miles east) and Wantage (15 miles south-west).
Around Northway
Locally, jobs take us to homes and businesses close to English Faculty Library, Bury Knowle Park and Cheney School and the streets around them. You will also find Rye St Antony School (0.8 miles south) and White Hart Inn (0.6 miles south-east). For rail, the closest station is Oxford station, about 2.4 miles south-west of the centre. Other landmarks nearby include Churchill Hospital (0.5 miles south) and Oxford Castle (2.2 miles south-west). Green spaces nearby include Headington Hill and CS Lewis Nature Reserve.
How to look after the new joints
A little care helps the new joints last. Our advice:
- Avoid pressure-washing directly into sealant joints
- Check external joints each spring
- Fix overflowing gutters above sealed joints
- Act on the first splits you see
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
Can I do it myself?
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.