West Berkshire · England
Kingsclere Window Mastic
Mastic around window and door frames, sills and patio doors for householders, landlords and businesses in Kingsclere. Fully insured, ARBOMaster approved and guaranteed for a year.
- Gaps where the sill meets the wall
- White mastic on grey or black frames
- Gaps left after new windows were fitted
Window mastic for homes and businesses in Kingsclere
Frames and walls don’t move together. Heat and cold make frames grow and shrink against brick or render that hardly moves. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. We’re often asked to deal with cracked or shrunken mastic around the frame and cracked sealant at the sill ends, across composite doors, patio & French doors and uPVC windows.
Homes around Kingsclere range from older properties to newer houses, and their windows range just as widely. The right sealant depends on the frame and on what it sits in.
There’s a 12-month guarantee on every job, whatever its size.
- Location
- Kingsclere (RG20)
- Region
- West Berkshire
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Work for landlords, hotels and businesses
For anyone letting property in or around Kingsclere, several properties can go on one quote. Just tell us the addresses and what each one needs.
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
How the job changes by surface
Window sills
Stone and concrete sills have their own joints, and the joint under the frame can let rain run behind. We seal those with a sealant suited to masonry.
Patio & French doors
Patio and French doors have the longest joints on most houses. Most leaks start at the bottom corners, so they get particular care.
Your questions about window mastic in Kingsclere
Do you work for landlords with property near Thatcham station?
Yes. We work for landlords and agents as well as householders, and several properties can be quoted together. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear quote.
Is Kingsclere within the area you cover?
Yes, Kingsclere is covered. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can I paint over the new sealant?
Silicone generally will not take paint. If you plan to paint, tell us first and we can use a paintable sealant where it suits the joint.
Where is Mr Mastic based?
We’re based in Crawley, and we cover South East England, London and all of Scotland.
Do you have insurance?
Yes. Mr Mastic is fully insured, and we’ve been doing sealant work for more than 20 years.
Do you seal inside as well as outside?
Yes. Draughts often come through the inside gap too, so it can be worth sealing both.
How much does window mastic cost in Kingsclere?
Size, access and the old material all affect the cost. Call for a quick quote.
Do I need to be at home?
We need access to the joints, so we will agree that with you when we book. Indoors, that normally means someone at home.
Honest limits
In fairness, some problems need a different trade:
- Condensation trapped between the panes
- Penetrating damp from a failed cavity tray or render
- A frame that has rotted at the joint
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
Surfaces we seal
- Composite doors
- Timber windows & doors
- uPVC windows
- Window sills
- Patio & French doors
- Aluminium frames
Signs you need window mastic in Kingsclere
Timber windows bring their own problems. Mastic painted over many times cracks with the paint, and the wood moves with damp as well as heat.
These are the problems we are asked about most:
- Mastic that is falling out in pieces
- Water coming in at the bottom corners of a door
- Whistling draughts around closed windows
- White mastic on grey or black frames
If you let a flat or house near Thatcham station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
What to look for in a quote
- Which colour the sealant will be
- Whether all the old sealant comes out first
- Whether VAT is included
- Whether the sealant suits the joint
The process
We work through the job in order: protect, prepare, seal, tidy. For most jobs that takes anything from an hour or two to a full day, depending on how many frames there are. A visit to Kingsclere is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
Before we arrive
- Keep pets and children clear of the area while we work
- Mention any sign-in or site rules at work premises
- Tell us about access, such as stairs, a lift or high-level joints
Get a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved and give you a clear price.
Read more
Kingsclere homes and the weather
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
In the older streets around Church of St Mary, frames set in older brick or stone need a sealant that suits the wall as well as the frame. For site and facilities teams at buildings such as Kingsclere Church of England Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Kingsclere is about 5 miles south-west of Tadley, in West Berkshire. We provide window mastic to homeowners, landlords and businesses in Kingsclere and the surrounding area, as part of our work across West Berkshire. Across West Berkshire, we cover 155 places, and Kingsclere is one of them. Our Reading page covers work nearby, about 14 miles away.
Every address in RG20 is within our area for window mastic. Streets in the area include King John Road, George Street and Garden Close, all of which we cover. We also cover the places around Kingsclere: Wolverton (2 miles east), Ecchinswell (2 miles west), Plastow Green (2 miles north), Fair Oak (2 miles north-east) and Headley (3 miles north). We also work in nearby towns such as Newbury (6 miles north-west), Thatcham (5 miles north), Burghfield Common (9 miles north-east), Speenhamland (7 miles north-west), Hungerford (13 miles north-west) and Spencers Wood (13 miles east).
Landmarks near Kingsclere
We work in homes and buildings around George And Horne Public House, among other places. Kingsclere’s nearest station is Thatcham station, roughly 4.8 miles north of the centre. Other landmarks nearby include Old Chapel Textile Centre (3.7 miles north-west) and West Berkshire Community Hospital (6 miles north). Green spaces nearby include Ladle Hill.
Looking after it afterwards
A little care helps the new joints last. Our advice:
- Avoid harsh chemicals near the mastic
- Wipe condensation off the frames
- Check the mastic once a year
- Keep paint off silicone joints
Try not to touch the new joint while it cures, for as long as we advise. Don’t point a pressure washer at the joints.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. Resealing closes it.
Also near Kingsclere
What else we do in Kingsclere
Can I do it myself?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
If you’ve already had a go yourself, that is fine. We cut it out and start again, so tell us about it when you ask for a quote.