Oxfordshire · England
Islip External Mastic
Our applicators work in Islip on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly.
- Joints with sealant missing in places
- Gaps where render, brick and frames meet
- Damp patches traced to an open external joint
External mastic in Islip
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render. If you have gaps where render, brick and frames meet and sealant that has lost its bond to the brick or render, we can put it right, whatever the surface.
External sealant needs dry, clean surfaces, so work around Islip is planned for dry weather. Let us know about access to every wall, plus any garages or outbuildings.
Whatever the size of the job, it’s backed by our 12-month guarantee.
- Place
- Islip (OX5)
- Region
- Oxfordshire
- Cover
- One year on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Should I try it myself first?
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
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 fails, we can still redo it.
What affects the quote in Islip
For a quick quote, just ask. The main things that affect it are:
- Any mould that needs treating
- The number of rooms or windows
- Access and height
- Any working-time requirements on site
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Helping us quote
You do not need to know the technical terms. Just tell us:
- Roughly how big the job is
- The address or postcode of the job
- If it’s domestic, commercial or a hotel
- Pictures of the joints, sent by email
We quote each job on its own, so start by telling us what you need. Simply call 0345 464 0079 or email us and describe the job and send photos if you have them.
The process
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, do the work and clear up. It usually takes a few hours to a few days, depending on the length of joint and the access. In a small place like Islip, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Getting ready for the visit
- Mention if the joints have been sealed before
- Where the joints are inside, avoid wetting them before we arrive
- Mention any leaks or damp you’ve noticed
Ask for a quote
For external mastic in Islip, call 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and you’ll get a clear quote before we start.
Related advice
Questions from Islip
Is Islip within the area you cover?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
I let a flat near Islip station. Can you help?
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’ll send you a clear quote.
How long does external mastic take?
It depends on the size of the job, but as a guide it takes a few hours for a handful of joints, longer for a whole elevation. We’ll give you a better idea when we quote.
Can you do several jobs on one visit?
Of course. Doing several areas at once is usually more efficient.
How much does external mastic cost in Islip?
It depends on the job, so we quote each one individually. To get one, call 0345 464 0079 or send us an email with a short description of the job.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
What’s an expansion joint in brickwork?
Walls move with heat, cold and moisture, so long walls have planned gaps to take that movement. The gap is sealed with a flexible sealant over backing rod.
Do you have insurance?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Honest limits
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Cracking across the wall rather than at a joint
- Failed render or damaged cladding panels
- Subsidence or other structural problems
If you are not sure, just ring 0345 464 0079 or send us an email and we will give you a straight answer before you book.
Surfaces we seal
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Façade panels
- Render & cladding joints
Landlords, agents and businesses in Islip
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we’ll quote.
Islip buildings and the weather
With historic houses such as Holywell Manor (about 4.6 miles south) nearby, there’s older building stock in the area around Islip 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. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Dr South's Church of England Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s. For an older house near a landmark such as St Nicholas' Church, 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 Islip station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Islip is about 5 miles north of Oxford, in Oxfordshire. Homes, rented property, offices and hotels in Islip is covered for external mastic, old or new, large or small. The work is guaranteed for a year. We cover 443 towns and villages across Oxfordshire, from the larger towns to small villages.
Jobs for external mastic in OX5 works the same way as everywhere else we cover. Local streets include High Street, King's Head Lane and Middle Way, all of which we cover. Close by, we work in Gosford (2 miles south-west), Hampton Poyle (2 miles north-west), Kidlington (2 miles west), Bletchingdon (3 miles north-west) and Weston-on-the-Green (3 miles north). Within a short drive, we also cover Oxford (5 miles south), Didcot (15 miles south), Bicester (6 miles north-east), Abingdon-on-Thames (10 miles south), Witney (11 miles west) and Thame (12 miles south-east).
Near you in Islip
We work in homes and buildings around The Red Lion Inn and Gosford Hill School, among other places. There’s a railway station in Islip itself: Islip station. Other landmarks nearby include Churchill Hospital (4.1 miles south). Open spaces near Islip include Otmoor RSPB reserve and Headington Hill.
Aftercare tips
A little care helps the new joints last. Our advice:
- Clear growth from the base of walls and joints
- Get split or bare joints resealed while the damage is small
- Avoid pressure-washing directly into sealant joints
- Check the sealant is paintable before painting near it
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Small splits are the time to act. At that stage it’s a simple cut out and reseal.
What else we do in Islip
What the job involves on each surface
Copings and trims
Metal and stone copings both move with temperature, so a flexible sealant suits them best year round.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joint sealant has to cope with frequent movement. We choose the product to suit.