Oxfordshire · England
Lower Assendon Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homeowners, landlords and businesses in Lower Assendon. Fully insured, ARBOMaster approved and guaranteed for a year.
- Mastic dropping out of the joint
- A silicone bead on a sash window that spoils the look
- Gaps where the frame meets the masonry
Can I do it myself?
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Sand mastic in Lower Assendon
Burnt sand mastic is a traditional material blends with stone and brick surrounds. It’s a good fit for period properties, where modern sealant can look out of place. Common call-outs are for gaps where the frame meets the masonry and wind and rain getting in round a sash window, across brick reveals, sash and case windows and stone surrounds.
In a village or hamlet like Lower Assendon, older cottages and farmhouses often have timber windows set in stone or brick. Older buildings like these do not always suit modern silicone, and sometimes a traditional sand mastic is the better choice.
All our work comes with a 12-month guarantee, wherever you are in Oxfordshire.
- Location
- Lower Assendon (RG9)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
Every visit runs the same way: we check the joints, protect the area around them, do the work and clear up. Most jobs take a few hours per window, depending on the condition of the joints. Somewhere as small as Lower Assendon, access is often the only tricky part. 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 finish is dressed so it sits neatly against the stone or brick.
Getting ready for the visit
- Let us know about parking restrictions
- Tell us about access, such as stairs, a lift or high-level joints
- Mention any sign-in or site rules at work premises
Getting a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.
Related advice
Signs you need sand mastic in Lower Assendon
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint.
Common reasons people contact us are:
- Failed mastic on an exposed elevation
- Draughty sash windows at the surround
- Open joints round the window box
- Old cement repairs round a window that have failed
If you look after a building such as Rupert House School, its window and door frames need their mastic kept sound, just like a home’s.
What to look for in a quote
- The length of the guarantee
- Are they insured?
- What happens if the job turns out different
- Who turns up on the day
Windows and doors in Lower Assendon
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Greys Court (about 1.6 miles south-west) are a reminder that the area around Lower Assendon has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
For an older house near a landmark such as Church of St Anne, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. For landlords with property near Henley-On-Thames station, any sash windows need sound mastic to keep draughts and rain out.
Lower Assendon is about 6 miles north of Caversham, in Oxfordshire. Homes, rented property, offices and hotels in Lower Assendon is covered for sand mastic. Every job comes with our 12-month guarantee. Lower Assendon is one of 443 towns and villages in Oxfordshire where we work for sand mastic. There’s also a page for Reading, about 8 miles away.
Here we cover the RG9 postcode area for sand mastic. If you need sand mastic at a property on Old Bix Road and Fair Mile or a nearby road, we can help. We also cover Middle Assendon (1 mile north-west), Bix (1 mile north-west), Fawley Bottom (1 mile north), Fawley (1 mile north-east) and Henley-on-Thames (2 miles south-east). Larger places within reach include Didcot (14 miles west), Thame (13 miles north), Benson (9 miles north-west), Chinnor (10 miles north), Tilehurst (8 miles south-west) and Wallingford (9 miles west).
Landmarks near Lower Assendon
Locally, jobs take us to homes and businesses close to Golden Ball Public House, Fawley Court and Temple Island and Gillotts School and the streets around them. For rail, the closest station is Henley-On-Thames station, roughly 1.9 miles south-east. Well-known places in the area include Frazer Nash Archives (2.2 miles south-east). The countryside around Lower Assendon includes Warburg Nature Reserve.
How the job changes by surface
Brick reveals
We rake out the old mastic and pack deep voids before the new mastic goes in.
Period and listed homes
Many older homes were built with sand mastic round the windows. If your home is listed, ask your local planning authority about consent.
Why act early in Lower Assendon
Filling over old, loose mastic doesn’t last. We remove the loose material first so the new mastic stays put. Older cottages and farmhouses around Lower Assendon can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
What you pay reflects the work, not guesswork. That’s why we ask a few questions first and give you a clear quote before we start.
Why us?
- Experience in homes, commercial sites and hotels
- 20+ years of sealant experience
- Any old sealant cut out fully, not covered over
- Every job guaranteed for a year
Read our cost guide or what customers say.
Lower Assendon questions
Will you come out to Lower Assendon?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you cover Lower Assendon for sand mastic?
Yes, Lower Assendon is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that normally means someone at home.
Do you have insurance?
Yes. Full insurance covers our work.
Can you match the sealant colour?
We will suggest a colour to suit the surroundings, from white and clear to greys and other shades. The choice depends on the product the joint needs.
Do you guarantee sand mastic work?
Our 12-month guarantee covers every job.
Which is right for my windows, sand mastic or modern sealant?
We’ll talk it through with you. Period homes often look best with sand mastic, and modern sealants suit newer frames.
Can you work on commercial sites?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Work for landlords, hotels and businesses
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will give you a quote.
Housing providers, facilities teams and property managers book us too. Several sites can go on one quote, and we are fully insured.
Places near Lower Assendon
What else we do in Lower Assendon
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Clear gutters so water does not pour onto the windows
- Renew mastic before redecorating the windows
- Have rotten timber repaired before new mastic goes in
- Go gently near the mastic when preparing windows
Keep gutters and sills clear so water runs away from the surround. Water sitting against the mastic shortens its life.
It’s best to renew mastic before painting the windows. Painting over failed mastic hides the problem for a while.