Oxfordshire · England
Longcot Sand Mastic
We cover Longcot for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Window mastic to renew ahead of painting
- Patchy fillers round a sash window
- Open joints round the window box
About our sand mastic in Longcot
On many period windows, sand mastic looks right and suits the building. On modern frames we’d normally use a flexible sealant and we will explain which is best for yours. If you have patchy fillers round a sash window and modern sealant on a period surround, we can help.
Outdoor sealant needs dry, clean surfaces, so work on frames around Longcot is planned for dry weather. Let us know about access to all the frames, upstairs ones included.
All our work comes with our one-year guarantee.
- Place
- Longcot (SN7)
- Region
- Oxfordshire
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
The process
When we arrive, we start by going over the job with you, so you know exactly what we are doing. Surfaces next to the work are protected before any work begins. The work generally takes a few hours for a single window, longer for several. Somewhere as small as Longcot, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We check the window surrounds and agree which joints need renewing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic is not too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
How to prepare
- Let us know about stairs, lifts or work at height
- Keep children and pets away from the work area
- Clear the area around the work
Ask for a quote
For sand mastic in Longcot, call 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and we’ll agree the price before any work begins.
Related advice
Signs you need sand mastic in Longcot
Some old mastic was never deep enough. A thin layer does not hold well so we make sure the new mastic is the right thickness.
The most common problems we see are:
- Mastic round period door frames that has failed
- Draughty sash windows at the surround
- Tired mastic found when preparing windows for paint
- Silicone on a period window that looks wrong
Homes close to Church of St Mary include some older properties, and the joint between an old wall and a newer frame is usually the first place rain gets in.
Before booking anyone
- Which sealant they’ll use, and why
- How the colour is chosen
- Whether they’re fully insured
- What guarantee comes with the work
Landlord and commercial work in Longcot
Landlords and letting agents in Longcot can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
Leave it or put it right?
Before painting the windows, it pays to renew the mastic. Paint over cracked mastic will not stop the gaps, and the new mastic is traditionally left unpainted. Where a wall is exposed, as many are in small places like Longcot, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
Why book with us
- Every job guaranteed for a year
- More than 20 years in sealant work
- Tidy, careful work
- We’re fully insured
Towns and villages near Longcot
More services for Longcot
Longcot homes and the weather
With historic houses such as Buscot Park (about 4.1 miles north-west) nearby, there’s older building stock in the area around Longcot as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as Longcot and Fernham Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Longcot is in Oxfordshire. We carry out sand mastic for householders, landlords and businesses in Longcot and nearby, as part of our work across Oxfordshire. Our area takes in 443 places across Oxfordshire. You can also see our page for Oxford, about 19 miles away.
Work in SN7 is quoted and booked the same way as anywhere else. Streets in the area include The Green, Church Close and Hughes Crescent, all of which we cover. Neighbouring places we cover for sand mastic include Fernham (1 mile north-east), Little Coxwell (2 miles north), Great Coxwell (2 miles north), Woolstone (2 miles south-east) and Uffington (2 miles south-east). We also work in nearby towns such as Abingdon-on-Thames (15 miles east), Witney (13 miles north-east), Carterton (10 miles north), Wantage (8 miles east), Grove (8 miles east) and Faringdon (3 miles north).
Landmarks near Longcot
Locally, jobs take us to homes and businesses close to Bricklayers Arms and Faringdon Community College, among other places. Well-known places in the area include Faringdon Day Hospital (2.9 miles north) and Uffington Museum (2.1 miles south-east). Green spaces nearby include Badbury Hill.
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Quotes for sand mastic in Longcot
The quote reflects the job in front of us. We look at:
- Whether old sealant or filler has to be cut out
- Any working-time requirements on site
- Whether the work is at height
- How many areas need sealing
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are unsure, phone 0345 464 0079 or send us an email for an honest opinion and a quote.
What we need to know
You don’t need to know the technical terms. It helps if you can tell us:
- The problem you’ve noticed
- Whether it has been sealed before
- If it’s domestic, commercial or a hotel
- The rough size of the job
Asking for a quote is easy: let us know what needs doing and where and its rough size. Photos by email help us understand the job, and we will take it from there.
Surface by surface
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. Sand mastic is shaped by hand to suit.
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. The method is the same as for windows.
Longcot: your questions answered
Is sand mastic in Longcot guaranteed?
Every job comes with our 12-month guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Is Longcot in your area for sand mastic?
Yes, Longcot is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or email us with a few details of the job.
Where do you work from?
Our base is in Crawley, West Sussex, and we work across South East England, London and Scotland.
Are you ARBOMaster approved?
Yes. We’re an ARBOMaster approved applicator, the approved applicator scheme for Arbo sealants.
How long does sand mastic take to harden?
The surface skins quite quickly, then hardens over a longer period. Timing depends on the weather and the joint.
Can I paint the new mastic?
It’s traditionally left unpainted, as guidance on traditional windows advises. Talk to us before any painting near it.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
How long does the job take?
As a guide, most jobs take a few hours for a single window, longer for several. Larger jobs naturally take longer, and we’ll tell you how long to expect.