Oxfordshire · England
Rowstock Sand Mastic
Our applicators work in Rowstock on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Failed mastic on an exposed elevation
- Old sand mastic that has cracked, crumbled or fallen out
- Draughts and rain around sash boxes
How we handle sand mastic in Rowstock
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditionally, sand mastic is left unpainted, so ask us before you decorate. We work on stone surrounds, timber door frames and tenement windows, and common reasons people get in touch are draughts and rain around sash boxes and silicone on a period window that looks wrong.
Mastic can only go onto a dry, clean joint, so window work in Rowstock is booked around the forecast. Tell us about access to every side of the house, including upper-floor windows.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Where
- Rowstock (OX11)
- Wider area
- Oxfordshire
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
DIY sealant or a professional job?
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
What sand mastic looks like in Rowstock
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.
If you look after a building such as Harwell Primary School, larger buildings have plenty of frames, and the mastic around each one ages. In the older streets around Church of St Matthew, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Rented homes near Didcot Parkway station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out.
Rowstock is about 3 miles west of Didcot, in Oxfordshire. Across the OX11 area, our applicators can take on sand mastic. Rowstock is one of 443 places in Oxfordshire where we work. For nearby work, see our Oxford page (11 miles or so).
Work in OX11 is quoted and booked the same way as anywhere else. Streets in the area include Tudor Walk, Wantage Road and Reading Road, and we cover them all. We also cover the places around Rowstock: 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). Within a short drive, 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).
Near you in Rowstock
Locally, jobs take us to homes and businesses close to Old Chequers pub and UTC Oxfordshire, among other places. The nearest railway station is Didcot Parkway station, roughly 3 miles east of the centre. A little further out are Atlas Computer Laboratory (1.7 miles south) and Abingdon Community Hospital (4.9 miles north). Not far away are Mowbray Fields and Churn Hill.
How the job changes by surface
Sash and case windows
Sash windows are where we do most sand mastic work. We renew the mastic round each box.
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. The method is the same as for windows.
Questions from Rowstock
Do you cover smaller places like Rowstock?
Yes, we do. We work across London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Do you work for landlords with property near Didcot Parkway station?
Yes, rental work is part of what we do. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Can you match the sealant colour?
Generally, yes. White, clear and grey are common, and other colours are available, and we will agree it with you first.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.
Where is Mr Mastic based?
Our base is Crawley. We work across South East England, London and Scotland.
When will the new mastic be hard?
The surface skins quite quickly and it hardens fully over a longer time. Timing depends on the weather and the joint.
Can you seal over the old sealant?
No. Fresh sealant does not stick to old sealant, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Is sand mastic better than silicone for my windows?
We’ll talk it through with you. Sand mastic suits many period homes, and modern sealants suit newer frames.
What happens if it’s left?
An open joint round the frame lets weather in. Water can get to the frame and the masonry so renewing it early protects the window. Where a wall is exposed, as many are in small places like Rowstock, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part.
Why us?
- We’re fully insured
- Neat joints and a tidy finish
- We never seal over old sealant
- Domestic, commercial and hotel work
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. Most jobs then take a few hours for a single window, longer for several. 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.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Getting ready for the visit
- Tell us about any water getting in
- Mention any sign-in or site rules at work premises
- Keep children and pets away from the work area
Ask for a quote
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work.
Read more
Aftercare tips
Simple care keeps the joints in good condition. We recommend:
- Take care around the mastic when scraping paint
- Get any rot dealt with first
- Make sure water runs off the sill
- Avoid patching sand mastic with silicone
Make sure water drains away from the window surround. Water sitting against the mastic shortens its life.
An open joint round the box lets weather through. Left, the gap tends to get bigger as more mastic falls out.
What we cannot put right
Before you book, it’s worth knowing the limits:
- Broken panes
- Decisions on consent for listed homes
- Sash cords, weights and draught-proofing of the sashes
If you are not sure, just call 0345 464 0079 or email us and we will give you a straight answer before booking.
Joints and surfaces we work on
- Timber door frames
- Brick reveals
- Period & listed homes
- Stone surrounds
- Sash and case windows
- Tenement windows
Landlords, agents and businesses in Rowstock
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.