Hertfordshire · England
Croxley Green Window Mastic
Specialist window mastic for Croxley Green: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Damp patches on the reveal after heavy rain
- Whistling draughts around closed windows
- Gaps between the frame and the inside reveal
What happens on the day
There isn’t much for you to do on the day. Show us the job and we will take it from there. The work itself takes anything from an hour or two to a full day, depending on how many frames there are from start to finish. Somewhere like Croxley Green needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We check each frame and agree which ones need doing.
- The old mastic is cut out and the surfaces cleaned back.
- Deep gaps are filled with backing rod to set the depth.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Finally we tidy up and check each joint.
Preparing for the visit
- Mention any tricky access
- Tell us if parking is tricky
- On commercial sites, let us know about site rules
Get a quote
We don’t publish a price list. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or email us.
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Window mastic in Croxley Green, done properly
Most frames have an outside joint and an inside one. The external joint is the weather seal; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. We work on composite doors, timber windows & doors and window sills, and the jobs we see most are cracked or shrunken mastic around the frame and black, perished sealant on frames.
Outdoor sealant needs dry, clean surfaces, so work on frames around Croxley Green is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
All our work is covered by a 12-month guarantee, wherever you are in Hertfordshire.
- Place
- Croxley Green (WD3, WD18)
- Wider area
- Hertfordshire
- Cover
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Keep paint off silicone joints
- Check the mastic once a year
- Ventilate rooms so frames do not stay wet inside
- Wash the frames with mild soapy water
On timber frames, keep the paintwork in good order, because bare, wet timber moves more and pulls at the joint. Keep paint off the silicone itself.
Look out for the warning signs: split or missing mastic, gaps, damp patches inside or black mould on the reveal. Any of these is worth a call.
For landlords and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
For anyone letting property in or around Croxley Green, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
What we are called out for in Croxley Green
Every frame moves through the day. A plastic or aluminium frame lengthens in sunshine and shortens as it cools, while the brick or render around it hardly moves. If the sealant cannot stretch, it splits.
Most people get in touch when they notice one of these:
- Draughts coming in around windows and doors
- Black, perished sealant on frames
- White mastic on grey or black frames
- Gaps where the sill meets the wall
If you live in an older home near St Oswald's Parish Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Questions to ask before booking
- How the surfaces are prepared before sealing
- What product goes in the joint
- What the quote includes, VAT included or not
- What the cure time is
Places near Croxley Green
More services for Croxley Green
Croxley Green questions
Can you help a landlord with a rental near Rickmansworth station?
Yes. We work for landlords and letting agents as well as homeowners, and several properties can go on one quote. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
Do you cover Croxley Green for window mastic?
Yes. Our work covers London and the South East, and Croxley Green is part of that. You can ring 0345 464 0079 or send us an email and let us know what needs doing.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We’ll give you the cure time for the product we used.
Can resealing stop a draught around my window?
In many cases. The gap between frame and wall is a common source of draughts, and resealing inside and out closes it.
How do I get a quote for window mastic in Croxley Green?
We do not publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. You will get a clear quote before work begins.
Can new sealant go over the old?
No, it will not last. It may look fine at first, but the new bead soon lifts. The old sealant has to come out completely.
Does the work come with a guarantee?
Yes. Each job is covered for 12 months, inside or out.
Will you leave a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
How we quote for window mastic
Every job gets its own quote. These are the things that affect it:
- Whether there’s mould to deal with
- How many rooms, windows or areas are involved
- The old material and how stubborn it is
- Which sealant suits the joint
The cost reflects the work involved, not guesswork. That’s why we ask about the job first.
Helping us quote
Before you ask for a quote, have a think about:
- Where the property is
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- What’s wrong with the joints now
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is. Whenever you’re ready, phone 0345 464 0079 or drop us an email.
When something else is needed
A few problems are outside what sealant work can do:
- Damp problems in the wall away from the window
- Worn gaskets, brush seals or a door that has dropped
- Soft or decayed wood in the frame
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before booking.
Joints and surfaces we work on
- Timber windows & doors
- Aluminium frames
- Composite doors
- uPVC windows
- Window sills
- Patio & French doors
Windows and doors in Croxley Green
Historic houses like Chenies Manor House (about 4.2 miles north-west) are a reminder that the area around Croxley Green has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For site and facilities teams at buildings such as Harvey Road Primary School, its window and door frames need their mastic kept sound, just like a home’s. If you let a flat or house near Rickmansworth station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Croxley Green is about 1 mile north-east of Rickmansworth, in Hertfordshire. Across the WD3 area, we can carry out window mastic at your property. Our Hertfordshire coverage runs to 381 places, Croxley Green among them. Our London page covers work nearby.
Our applicators cover all of the WD3 and WD18 postcode area for window mastic and the streets around it. Window mastic is available to properties on New Road, Harvey Road and Bateman Road. If you’re just outside Croxley Green, we cover Holywell (1 mile east), Rickmansworth (1 mile south-west), Batchworth (1 mile south-west), Chorleywood West (2 miles west) and Moor Park (2 miles south). Larger places within reach include Hemel Hempstead (7 miles north), St Albans (9 miles north-east), Welwyn Garden City (15 miles north-east), Harpenden (12 miles north), Hatfield (12 miles north-east) and Borehamwood (7 miles east).
What’s near Croxley Green
Around Croxley Green, our work takes us to homes and buildings near Croxley Danes School, Rickmansworth School and The Red House, among other places. Croxley Green’s nearest station is Rickmansworth station, roughly 1.3 miles west of the centre. Well-known places in the area include Hertfordshire Fire Brigade Museum (2.4 miles east) and Hilfield Castle (4.7 miles east). For a walk, there’s Chorleywood Common and Tumbling Bay.
What happens if it’s left?
Running fresh sealant over the old joint is tempting, but it will not grip old, dirty sealant. It peels before long, and water still gets in behind. The old mastic has to come out. Older cottages and farmhouses around Croxley Green can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Doing several joints on one visit is usually more efficient than separate visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
What you get with us
- We leave the area clean and tidy
- Over 20 years’ experience
- ARBOMaster approved applicator
- Sealant colour chosen to suit
Take a look at what affects the cost or our reviews.