West Berkshire · England
Window Mastic in Thatcham
Window mastic for Thatcham, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Cracked or shrunken mastic around the frame
- Rushed sealant from a window installation
- Old mastic that has gone black or come away
How we handle window mastic in Thatcham
The mastic around a window or door seals the gap between the frame and the wall. Once that seal fails, wind and rain find the gap. The old mastic is removed and the joint resealed with a flexible exterior sealant. If you’re dealing with untidy mastic left by window fitters and old mastic that has gone black or come away, we can help, on patio & French doors, uPVC windows and window sills alike.
In a town like Thatcham, the windows on the most exposed side of a house take the brunt of the rain, and that’s normally where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
Each job carries a 12-month guarantee, large or small.
- Place
- Thatcham (RG19, RG18)
- Region
- West Berkshire
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
How the job changes by surface
Window sills
Where a sill meets brick or render, the ends often crack first. A tight seal at each end keeps rain out of the wall.
Aluminium frames
Metal frames expand in the sun and are often slim, with little room for error. A neat, narrow bead in a colour to match suits the frame.
What affects the quote in Thatcham
For a quick quote, just ask. What matters most is:
- The number and length of the joints
- When we can work, for business premises
- How many areas need sealing
- How much old sealant there is and how hard it is to remove
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
What to tell us for a quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- The type of property
- Access, such as stairs, a lift or height
- The problem you’ve noticed
- Where the job is, and your postcode
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we will explain what’s involved before giving you a price.
Also in Thatcham
How it works
We keep the work tidy and contained to the area we’re working on, so you can get on with your day. Expect the work to take a morning for a couple of windows and a door, and we tell you how long to leave it before we go. In Thatcham, parking is rarely complicated, though it helps to know about driveways or restrictions, and let us know if the work is upstairs, in a flat or up high outside.
- We check how each frame can be reached safely.
- Old, cracked mastic is removed completely.
- Frame and wall are cleaned and must be dry before sealing.
- Deep voids are backed, then the sealant is gunned in.
- The joint is shaped to shed water and the area tidied.
Before we arrive
- Mention any sign-in or site rules at work premises
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about earlier repairs to the joints
Get a quote
Every job is quoted individually. Just phone 0345 464 0079 or send us an email with the details and send pictures if you have them.
Related advice
Windows and doors in Thatcham
Historic houses like Shaw House (about 2.7 miles west) are a reminder that the area around Thatcham has older buildings as well as new. Where a home is older, 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, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Letting a property close to Thatcham station? Then cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. Homes close to United Reformed Church include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Thatcham is about 12 miles north-west of Basingstoke, in West Berkshire. Across the RG19 area, we can carry out window mastic at your property. Across West Berkshire, we cover 155 places, Thatcham among them. You can also see our page for Reading, about 13 miles away.
Work in RG19 and RG18 works the same way as everywhere else we cover. Whether your property is on High Street, Station Road and Flagstaff Square or a nearby road, our applicators can take on the job. Main roads around Thatcham include the A4, so getting to you is simple. Other places close to Thatcham include Benham Hill (1 mile west), Ashmore Green (2 miles north-west), Cold Ash (2 miles north), Upper Bucklebury (2 miles north-east) and Stone Copse (2 miles north-west). Within a short drive, we also cover Newbury (3 miles west), Burghfield Common (8 miles east), Speenhamland (3 miles west), Hungerford (11 miles west), Spencers Wood (12 miles east) and Calcot (9 miles east). Being one of West Berkshire’s larger places, Thatcham has homes, rented property and businesses of every kind.
Near you in Thatcham
Locally, jobs take us to homes and businesses close to Kennet School and The Old Chequers Public House. Thatcham’s nearest station is Thatcham station, about 0.9 miles south-east of the centre. A little further out are Old Chapel Textile Centre (2.2 miles south-west) and West Berkshire Community Hospital (1.5 miles west). Not far away are Nature Discovery Centre.
Looking after it afterwards
So the new joints stay in good condition:
- Check the mastic once a year
- Clear any debris from frame drain holes
- Keep solvents and bleach off the sealant
- Clean frames with a soft cloth and soapy water
Keep the new mastic undisturbed while it cures, for as long as we advise. Keep jet washers away from the frames.
A failed joint lets water into the wall a little at a time. Often the first sign is a damp patch inside or flaking paint on the reveal. Catching it early keeps the fix to a reseal.
What we can’t put right
We won’t take on work that won’t last, so these are the limits:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- Rotten timber, which needs a joiner first
- Broken hinges, locks or handles
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we will tell you honestly.
Joints and surfaces we work on
- Window sills
- uPVC windows
- Timber windows & doors
- Aluminium frames
- Composite doors
- Patio & French doors
FAQs for Thatcham
What guarantee comes with window mastic in Thatcham?
Every job comes with our 12-month guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Do you cover Thatcham for window mastic?
Yes, Thatcham is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job.
Do you hold any approvals?
Yes. We’re an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
Do you work for letting agents?
Yes. As well as householders, we work for landlords, agents, businesses and hotels.
Can new sealant go over the old?
No, it won’t last. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
I’m a tenant. Can you help?
Yes, though it’s best to check with your landlord first. Landlords are often happy for the work to be arranged.
How long should I leave it?
Different products cure at different speeds, so follow the cure time we give you when we finish.
Where do you work from?
We’re based in Crawley, and we cover South East England, London and all of Scotland.
What we’re called out for in Thatcham
Plenty of failed mastic was poorly applied in the first place. Sealant run over dust, wet brick or loose mortar never bonded as it should, so it comes away long before its time.
The most common problems we see are:
- Mastic that has split away from the wall
- Draughty joints inside around the window
- Cold air getting in at the frame edge
- Old mastic that has gone black or come away
If you look after a building such as Spurcroft Primary School, the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- What happens if the job turns out different
- What product goes in the joint
- What the cure time is
- Whether all the old sealant comes out first