Reading · England
Sonning Window Mastic
Window and door frames in Sonning need attention? We remove the old material, prepare the joints and seal them properly, with a 12-month guarantee.
- Gaps between the frame and the inside reveal
- Water coming in at the bottom corners of a door
- Cracked or shrunken mastic around the frame
Window mastic for homes and businesses in Sonning
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. So the sealant has to stretch and recover, which is why we use a low-modulus product. We work on aluminium frames, window sills and timber windows & doors, and the jobs we see most are cracked or shrunken mastic around the frame and cracked internal joints between frame and plaster.
Homes in small places like Sonning often stand in the open, with little to shelter their windows from wind and rain. Exposed frames and sills lose their mastic sooner than sheltered ones.
All of our work is guaranteed for twelve months, in Sonning and everywhere else we cover.
- Where
- Sonning (RG4)
- Region
- Reading
- Guarantee
- A year, on every job
- Quotes
- A clear price before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens if it’s left?
Once mastic fails, rain can get between the frame and the wall. Left long enough, it can stain inside walls, spoil plaster and rot wooden frames. Resealing now is a small job by comparison. In a small place like Sonning, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Call for a quick quote and we will go through it with you.
What you get with us
- Trusted Arbo and Everbuild sealants
- Rated 4.9 stars on Google
- Domestic, commercial and hotel work
- Any old sealant cut out fully, not covered over
See what affects the cost and what customers say.
Surface by surface
Patio & French doors
Heavy door frames can move more than windows. A flexible sealant copes with that without cracking.
Aluminium frames
Metal frames expand in the sun and are often slim, with little room for error. A tidy bead in anthracite grey, black or a matching colour keeps the clean look.
DIY versus a professional finish
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
Common problems we fix in Sonning
On timber frames, paint and putty build up around the joint. Mastic painted over many times cracks with the paint, and the wood moves with damp as well as heat.
Any of these means the joints need attention:
- Untidy mastic left by window fitters
- White mastic on grey or black frames
- Leaking joints at the ends of sills
- Draughty joints inside around the window
In the older streets around St Andrew's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Before you book anyone
- Whether you can choose the colour
- Is the old sealant removed completely?
- How the surfaces are prepared before sealing
- Whether VAT is included
How the visit works
On the day, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before any work begins. Most jobs take most of a day for a typical house, less for a few frames. Somewhere as small as Sonning, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We check each frame and agree which ones need doing.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- We clear up and check every joint is fully closed.
Getting ready for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Clear items away from the joints we’re working on
- On commercial sites, let us know about site rules
Getting a quote
For a quote, phone 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We’ll give you a clear price before any work starts.
Related advice
Aftercare tips
How long the joints last depends on use and care. Here’s what we suggest:
- Avoid blasting the frames with a pressure washer
- Keep drainage slots and sill grooves clear
- Use gentle cleaners on frames and sealant
- Do not paint over the silicone
Keep the new mastic undisturbed while it cures, following the cure time we give you. Keep jet washers away from the frames.
A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. A new joint closes it up.
Landlord and commercial work in Sonning
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
We also work for property managers and facilities teams in Sonning and across Reading. Several sites can be quoted together.
FAQs for Sonning
Can you help a landlord with a rental near Twyford station?
Yes, we work for landlords and agents. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Is Sonning in your area for window mastic?
Yes, Sonning 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 tell us what needs doing.
Do I need to be at home?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
Can you do the inside joint as well?
Yes. Plenty of draughts come through the inside joint as well as the outside, so sealing both is often worthwhile.
Do you have insurance?
Yes, we are fully insured.
What information do you need?
Let us know what needs doing and where. If we need more, we’ll ask.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We will tell you how long to leave the joint before we leave.
What window mastic looks like in Sonning
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For landlords with property near Twyford station, renewing tired window mastic between tenants heads off draught and damp complaints. For site and facilities teams at buildings such as Sonning Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Sonning is about 1 mile north-west of Woodley, in Reading. If you need window mastic in Sonning, please call 0345 464 0079 or email us for a quick quote. We are based in Crawley and cover Reading, Sonning included. Sonning is one of 34 towns and villages in Reading where we work.
Jobs for window mastic in RG4 works the same way as everywhere else we cover. Local streets include High Street, Parkway Drive and Pound Lane. Sonning sits on or near the B478 and B4446. Neighbouring places we cover for window mastic include Play Hatch (1 mile north-west), Dunsden Green (2 miles north-west), Newtown (2 miles south-west), Caversham Park Village (2 miles north-west) and Littlestead Green (2 miles north-west). We also work in nearby towns such as Caversham (3 miles west), Norcot (5 miles west), West Reading (4 miles west), Tilehurst Within (5 miles west), Shinfield (5 miles south-west) and Arborfield Garrison (6 miles south).
Around Sonning
Around Sonning, our work takes us to homes and buildings near Ali's Pond Local Nature Reserve, Bull Inn and Waingels College. The nearest railway station is Twyford station, about 1.9 miles east. Well-known places in the area include Berkshire Medical Heritage Centre Museum (2.5 miles south-west) and Royal Berkshire Hospital (2.6 miles south-west). Green spaces nearby include Sonning Hill and South Lake.