Oxfordshire · England
Window & door mastic in St John Street area, Oxfordshire
Mastic around window and door frames, sills and patio doors for homes and businesses in St John Street area and across Oxfordshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Rushed sealant from a window installation
- Cold air getting in at the frame edge
- Damp patches on the reveal after heavy rain
About our window mastic in St John Street area
A window frame and the wall around it expand and shrink at different rates. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. We work on timber windows & doors, patio & French doors and composite doors, and common reasons people get in touch are mastic that’s falling out in pieces and sealant in the wrong colour for the frame.
Homes around St John Street area range from older properties to newer houses, and their windows range just as widely. Each frame material needs the right sealant against the right wall.
Each job carries a 12-month guarantee.
- Place
- St John Street area (OX1, OX2)
- Wider area
- Oxfordshire
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What happens on the day
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The work itself takes most of a day for a typical house, less for a few frames. For a job in St John Street area, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away, along with any loose debris.
- Frame and wall are cleaned and must be dry before sealing.
- Deep voids are backed, then the sealant is gunned in.
- The joint is shaped to shed water and the area tidied.
Preparing for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about parking restrictions
- Clear the area around the work
How to get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Advice
When something else is needed
A few problems are outside what sealant work can do:
- A door that needs adjusting, rehanging or new seals
- Misting between the panes of a double-glazed unit (that needs a new unit)
- A frame that has rotted at the joint
If you are not sure, just ring 0345 464 0079 or send us an email and we will give you a straight answer.
Joints and surfaces we work on
- Patio & French doors
- Aluminium frames
- Composite doors
- Timber windows & doors
- uPVC windows
- Window sills
How the job changes by surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A neat, narrow bead in a colour to match keeps the clean look.
Composite doors
A composite door usually sits in a plastic outer frame, and the joint around it is sealed like a window. We match the colour to the frame.
How to look after the new joints
Simple care keeps the joints in good condition. Our advice:
- Keep paint and stain on wooden frames in good order
- Keep solvents and bleach off the sealant
- Wipe condensation off the frames
- Look round the frames every year or so
Most silicone sealants will not take paint, so mention any painting plans before any work starts. We can use a paintable sealant where that matters.
Water gets in quietly when mastic fails. You might not see it until plaster blows or a damp patch appears inside. Catching it early keeps the fix to a reseal.
Landlords, agents and businesses in St John Street area
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together.
If you manage several properties in or around St John Street area, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs.
When to call us in St John Street area
Plenty of failed mastic was poorly applied in the first place. Mastic laid onto dusty, damp or crumbling surfaces never bonded as it should, so it comes away long before its time.
People usually contact us after spotting one of these:
- Gaps where the sill meets the wall
- Old mastic that has gone black or come away
- Whistling draughts around closed windows
- Untidy mastic left by window fitters
For landlords with property near Oxford station, renewing tired window mastic between tenants heads off draught and damp complaints.
What to look for in a quote
- What insurance they hold
- Which sealant they’ll use, and why
- How long the guarantee is
- Who turns up on the day
St John Street area questions
Do you work for landlords with property near Oxford station?
Yes, we work for landlords and letting agents. You can call 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Do you cover St John Street area for window mastic?
Yes, St John Street area is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or email us with a few details of the job, and we’ll give you a clear quote.
Can new window sealant be painted?
Not generally, if it’s silicone. We choose the product with your decorating in mind, so mention it when you book.
How long does it take to reseal the windows on a house?
A handful of frames is a short visit. You’ll get a timescale with the quote.
Is it OK to seal over old sealant?
No. New silicone will not bond to old silicone, and it traps any mould or water underneath. We remove it all first.
Are you ARBOMaster approved?
Yes. We are approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Can you do the inside joint as well?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Do you take out the old sealant first?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
DIY versus a professional finish
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
If you’ve already had a go yourself, that is fine. We cut it out and start again, so tell us about it when you ask for a quote.
Nearby places to St John Street area
Also in St John Street area
St John Street area homes and the weather
With historic houses such as Holywell Manor (about 0.6 miles east) nearby, there’s older building stock in the area around St John Street area as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. 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.
Schools such as The Eckersley School of English are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. Homes close to Pusey House Chapel include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
St John Street area is about 1 mile west of Oxford, in Oxfordshire. Homes, rented property, offices and hotels in St John Street area can book us for window mastic. Every job comes with our one-year guarantee. We cover 443 towns and villages across Oxfordshire.
We work across OX1 and OX2 for window mastic. Streets in the area include New Road, Shoe Lane and Love Lane. Main roads around St John Street area include the A420 and A4144, which makes travel easy. Nearby, we also carry out window mastic in St. Ebbes (1 mile south), Jericho (1 mile north-west), Osney (1 mile south-west), Walton Manor (1 mile north) and Norham Manor (1 mile north). Within a short drive, we also cover Didcot (10 miles south), Bicester (11 miles north-east), Abingdon-on-Thames (6 miles south), Witney (10 miles west), Carterton (14 miles west) and Thame (12 miles east).
Local landmarks in St John Street area
We work in homes and buildings around St Barnabas' Church of England Aided Primary School, Oxford University Parks and The Eagle and Child pub and the streets around them. Other local landmarks include Angus Library and Archive (less than half a mile north-east) and Oxford Academy (1.3 miles north). There’s a railway station in St John Street area itself: Oxford station. Nearby you’ll also find Oxford University Press Museum (under half a mile north-west) and Oxford Castle (less than half a mile south). Green spaces nearby include Hook Meadow and The Trap Grounds and Headington Hill.