Oxfordshire · England
Fernham Sand Mastic
Professional sand mastic in and around Fernham, with every bit of old sealant taken out first and a 12-month guarantee.
- Window mastic to renew ahead of painting
- Weathered mastic on the most exposed windows
- Draughts and rain around sash boxes
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Keep sills and gutters clear so water drains away
- Inspect the joints round the windows every year or so
- Take care around the mastic when scraping paint
- Sort the mastic before the decorators arrive
Keep paint scrapers and sanders off the mastic when redecorating. It can be damaged by heavy scraping.
It’s best to renew mastic before painting the windows. Painting over failed mastic hides the problem for a while.
How we handle sand mastic in Fernham
Silicone on a period window often looks wrong and does not suit the building. Sand mastic gives a finish that matches the age of the house and we can swap the silicone for it. Common call-outs are for old cement repairs round a window that have failed and wind and rain getting in round a sash window, on tenement windows, timber door frames and period & listed homes.
Homes in small places like Fernham often stand in the open, with little to shelter their windows from wind and rain. That exposure dries out and cracks the mastic around frames and sills faster.
Big or small, you get the same 12-month guarantee in Fernham and across Oxfordshire.
- Where
- Fernham (SN7)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What else we do in Fernham
Can I do it myself?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
A DIY attempt does not rule out a professional job. We cut it out and start again.
Fernham homes and the weather
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Buscot Park (about 4.3 miles north-west) nearby, there’s older building stock in the area around Fernham 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.
If you live in an older home near Church of St John, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Fernham is about 7 miles west of Wantage, in Oxfordshire. We provide sand mastic to homes and businesses in Fernham and the surrounding area. 443 places in Oxfordshire are on our list. There’s also a page for Oxford, roughly 17 miles from Fernham.
Here we cover the SN7 postcode area for sand mastic. You will find streets such as High Street, Church Lane and The Green, and we cover them all. Neighbouring places we cover for sand mastic include Little Coxwell (1 mile north-west), Baulking (2 miles south-east), Uffington (2 miles south-east), Shellingford (2 miles north-east) and Faringdon (2 miles north). Larger places within reach include Didcot (14 miles east), Abingdon-on-Thames (13 miles east), Witney (12 miles north), Carterton (10 miles north), Wantage (7 miles east) and Grove (7 miles east).
What’s near Fernham
Well-known places in the area include Faringdon Castle (2.4 miles north) and Uffington Museum (1.8 miles south). For a walk, there’s Badbury Hill.
Surface by surface
Period and listed homes
Materials matter on listed and conservation-area homes. Sand mastic is often the preferred finish.
Timber door frames
A neat sand mastic joint round a front door suits a period home.
What we are called out for in Fernham
Paint, silicone or cement used over old mastic causes problems. They don’t suit the joint and we normally remove them.
If you can see any of these, it’s time to have the joints looked at:
- A silicone bead on a sash window that spoils the look
- Window mastic to renew ahead of painting
- Open joints round the window box
- Draughts and rain around sash boxes
If you look after a building such as Faringdon Community College, the mastic around its windows and doors needs looking after like any other building’s.
Before you book anyone
- Which sealant they’ll use, and why
- What insurance they hold
- How long to leave it before use
- The length of the guarantee
For landlords and businesses
We also work for property managers and facilities teams. Several sites can go on one quote.
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Common questions in Fernham
Will you come out to Fernham?
Yes, we do. We work across London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
Is Fernham in your area for sand mastic?
Yes, Fernham is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job.
What exactly is sand mastic?
It’s sand mixed with a linseed-oil-based binder for the joint between timber frames and masonry.
How long does sand mastic take to go off?
A skin forms quite soon, but full hardening takes longer. We will tell you what to expect for your job.
What should I tell you?
The location, the problem and the rough size of the job. Photos by email help too.
Can I paint the new mastic?
The usual advice is to leave sand mastic unpainted. If you’re redecorating the window, ask us first and we’ll advise.
Should I use sand mastic or silicone?
For period timber windows in stone or brick, sand mastic is often the better fit. Modern frames normally suit a flexible sealant.
Are you an approved applicator?
Yes. We are approved under the ARBOMaster scheme.
What affects the quote in Fernham
Jobs vary more than people expect. What affects the quote:
- Whether the work is at height
- How many areas need sealing
- Whether old sealant or filler has to be cut out
- Which sealant suits the joint
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Asking for a quote
What to tell us when you ask for a quote:
- The type of property
- Access, such as stairs, a lift or height
- Any previous sealing or DIY work
- How many joints, rooms or windows are involved
We quote each job on its own, so the first step is telling us about yours. Just phone 0345 464 0079 or send us an email with the details.
How it works
There’s no need to move everything out before we come, just the space around the work. We protect the rest, and the job takes a few hours for a single window, longer for several in most cases. Somewhere like Fernham needs a little journey planning: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- First, we look at the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- The mastic is mixed, pressed into the joint by hand and shaped.
- We dress the surface so it sits neatly against the masonry.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us about any previous sealing or DIY attempts
- Tell us if parking is tricky
Get a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. Whenever you are ready, call 0345 464 0079 or send us an email.