Hertfordshire · England
Window Mastic in Throcking
Mastic around window and door frames, sills and patio doors in Throcking, with a one-year guarantee on every job. Ask us for a quote.
- Draughts coming in around windows and doors
- Sealant in the wrong colour for the frame
- Cracked internal joints between frame and plaster
Window mastic for homes and businesses in Throcking
Every window and door frame has a gap around it, and mastic is what closes it. When it cracks, hardens or pulls away, draughts and rain get in. Our applicators cut it out and replace it with a flexible, weatherproof sealant. We work on window sills, timber windows & doors and aluminium frames, and the jobs we see most are rushed sealant from a window installation and old mastic that has gone black or come away.
In a village or hamlet like Throcking, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, so the sealant has to be chosen to suit the building.
You get a 12-month guarantee, the same in Throcking as everywhere else we work.
- Place
- Throcking (SG9)
- Region
- Hertfordshire
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What happens on the day
Before we leave, we go over the finished joints with you. The visit itself generally takes a few hours for a few frames, or a day or more for a whole house, depending on the amount of work. Somewhere as small as Throcking, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We check each frame and agree which ones need doing.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Finally we tidy up and check each joint.
How to prepare
- Tell us if parking is tricky
- Let us know about stairs, lifts or work at height
- Clear items away from the joints we’re working on
Get a quote
We quote each job on its own. Simply call 0345 464 0079 or drop us an email and describe the job.
Related advice
Should I try it myself first?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is.
Frames and glazing around Throcking
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.
If you live in an older home near Holy Trinity Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Throcking is about 6 miles north-east of Stevenage, in Hertfordshire. If you need window mastic in Throcking, it’s easy to get a quote: please phone 0345 464 0079 or send us an email. We cover Hertfordshire from our Crawley base, Throcking included. Throcking is one of 381 towns and villages in Hertfordshire where we work for window mastic. Our Chelmsford page covers work nearby, about 28 miles away.
Every address in SG9 is covered for window mastic. We also cover the places around Throcking: Cottered (1 mile south-west), Chipping (1 mile north-east), Buntingford (2 miles east), Aspenden (2 miles south-east) and Layston (2 miles east). Within a short drive, we also cover Stevenage (6 miles south-west), Bishop's Stortford (11 miles south-east), Welwyn Garden City (12 miles south-west), Hitchin (9 miles west), Hoddesdon (14 miles south) and Hatfield (15 miles south-west).
Around Throcking
Well-known places in the area include Clothall Castle (4.1 miles west). Green spaces nearby include Hawkins Wood.
How the job changes by surface
Composite doors
Front doors take the weather head on. We pay most attention there.
uPVC windows
We clean the frame edge carefully so the plastic is not marked, then the new bead is laid against the frame and the wall and tooled smooth.
Looking after it afterwards
So the new joints stay in good condition:
- Repaint timber before it’s bare
- Air rooms to keep condensation down around windows
- Make sure the drainage slots are not blocked
- Use gentle cleaners on frames and sealant
Have a look at the joints once a year, ideally after winter. Small splits are simple to catch before they leak.
A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. Resealing closes it.
Landlord and commercial work in Throcking
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together, and we’re fully insured.
Common problems we fix in Throcking
Water runs down the glass onto the sill, so the sill ends and the joint below the frame are common leak points. When that sealant fails, water gets into the wall or under the frame.
These are the problems we’re asked about most:
- Old mastic that has gone black or come away
- Draughty joints inside around the window
- Cold air getting in at the frame edge
- Leaking joints at the ends of sills
For site and facilities teams at buildings such as Freman College, the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- When the joint can take water or movement
- Which colour the sealant will be
- Is the old sealant removed completely?
- Whether they’re fully insured
Other services in Throcking
What happens if it’s left?
Not every sealant suits a window. Decorators’ caulk and bathroom silicone aren’t designed for outside joints that move. An exterior, low-modulus sealant stays flexible in sun and frost. Where a wall is exposed, as many are in small places like Throcking, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or email us.
Why Throcking customers choose us
- Full insurance on every job
- Arbo and Everbuild products
- We never seal over old sealant
- Homes, businesses and hotels
Take a look at our cost guide and what customers say.
Your questions about window mastic in Throcking
Is Throcking in your area for window mastic?
Yes, Throcking is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear price.
Is window mastic in Throcking guaranteed?
All our work, in Throcking and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
What does window mastic cost?
Size, access and the old material all affect the cost. Call for a quick quote.
I’m a tenant. Can you help?
Yes, but check with your landlord or agent first. Many landlords are glad to have it sorted.
How many windows can you do in a day?
Allow most of a day for a typical house, less for a few frames. Access and the amount of old mastic make the biggest difference.
Where do you work from?
We are based in Crawley, and we cover South East England, London and all of Scotland.
Do you seal inside as well as outside?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
Do the sealants smell?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.