Oxfordshire · England
Postcombe Sand Mastic
Professional sand mastic in and around Postcombe, with every bit of old sealant taken out first and a 12-month guarantee.
- Gaps round a timber door in stone or brick
- Modern sealant on a period surround
- Open joints round the window box
Sand mastic in Postcombe
A silicone bead around a sash window can look out of place and isn’t always the right material. Sand mastic is the traditional choice, and we can replace one with the other. If you have gaps where the frame meets the masonry and crumbling sand mastic round a window, we can put it right.
In a village or hamlet like Postcombe, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, and sometimes a traditional sand mastic is the better choice.
All our work comes with our 12-month guarantee.
- Location
- Postcombe (OX9)
- Wider area
- Oxfordshire
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Postcombe questions
Is sand mastic in Postcombe guaranteed?
Every job comes with our 12-month guarantee, wherever it is. We’re also fully insured and ARBOMaster approved.
Is Postcombe within the area you cover?
Yes, Postcombe is covered. We work across London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
Can you quote for more than one area?
Yes. Just list everything you need and we’ll quote it together.
Which products do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before resealing.
Is it possible to take out silicone and use sand mastic instead?
Usually, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
Can you work on commercial sites?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Is it possible to paint over sand mastic?
It’s traditionally left unpainted, as guidance on traditional windows advises. Ask us before decorating.
Do you need sand mastic in Postcombe?
Rain on the window surround works into any crack and pushes it out. Exposed elevations usually fail first.
Keep an eye out for these signs:
- Wind and rain getting in round a sash window
- Gaps where the frame meets the masonry
- Failed mastic on an exposed elevation
- Cracked mastic round a front door frame
If you live in an older home near Church of St Mary, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What your quote should include
- How the joint is cleaned and prepared
- What the quote includes, VAT included or not
- Whether they seal over old material or remove it
- Are they insured?
The process
The work is kept neat and contained to the joints we’re treating, so you can carry on as normal. Expect the work to take anything from a few hours to a full day, depending on how many windows. In a small place like Postcombe, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we look at the surrounds with you and agree what needs doing.
- Old, loose mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The mastic is finished to sit tidily against the stone or brick.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Keep children and pets away from the work area
- For business premises, tell us about site rules or sign-in
Ask for a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll talk you through the work and give you a clear quote.
Advice
Towns and villages near Postcombe
What else we do in Postcombe
When it isn’t the sealant
We’d rather tell you now than do work that will not last, so these are the limits:
- Cracked or broken glass
- Damaged stone surrounds
- Sashes that need overhauling
If you are not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer.
Where we work in Postcombe
- Sash and case windows
- Tenement windows
- Brick reveals
- Period & listed homes
- Stone surrounds
- Timber door frames
Different surfaces, different methods
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. Sand mastic seals the joint round it.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Aftercare tips
After the cure time, these simple habits help:
- Get any rot dealt with first
- Do not run silicone over sand mastic
- Keep sills and gutters clear so water drains away
- Plan mastic work ahead of painting
Make sure water drains away from the window surround. Constant wetting wears the mastic faster.
It’s best to renew mastic before painting the windows. Painting over failed mastic hides the problem for a while.
DIY versus a professional finish
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. All the old material has to come out first.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What sand mastic looks like in Postcombe
With historic houses such as Adwell House (about 0.8 miles west) nearby, there’s older building stock in the area around Postcombe as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Around Postcombe, as everywhere, sand mastic is only as good as the preparation behind it.
Postcombe is about 4 miles south of Thame, in Oxfordshire. Wherever you are in the OX9 postcode area, we can carry out sand mastic at your property. Our Oxfordshire coverage runs to 443 places, and Postcombe is one of them. Oxford is on our list too, around 12 miles away.
Postcode districts we cover here for sand mastic: OX9. Local streets include London Road, Salt Lane and Beech Farm Close. Nearby, we also carry out sand mastic in South Weston (1 mile south-west), Aston Rowant (1 mile east), Lewknor (1 mile south), Kingston Blount (2 miles east) and Crowell (2 miles east). Further out, we also cover Oxford (12 miles west), Didcot (13 miles south-west), Abingdon-on-Thames (13 miles west), Thame (4 miles north), Henley-on-Thames (11 miles south) and Benson (7 miles south-west).
Local landmarks in Postcombe
Locally, jobs take us to homes and businesses close to England's Rose pub. A little further out are Thame Community Hospital (3.8 miles north). The countryside around Postcombe includes Aston Rowant NNR and Bald Hill.
What happens if it’s left?
An open joint round the frame lets weather in. Left, water can reach the timber and the wall, so dealing with it now protects both. In a small place like Postcombe, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
Doing several joints on one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll give you a clear price for the lot.
What you get with us
- Experience in homes, commercial sites and hotels
- 12-month guarantee on every job
- Trusted Arbo and Everbuild sealants
- More than 20 years in sealant work
Take a look at how sealant jobs are priced or our reviews.