Hertfordshire · England
Window & door mastic in The Folly, Hertfordshire
Specialist window mastic for The Folly: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Mastic that is falling out in pieces
- Gaps where the sill meets the wall
- Cracked internal joints between frame and plaster
Window mastic in The Folly, done properly
Colour matters on a frame. We can seal in white, brown, anthracite grey, black or clear, so the bead blends with the window rather than framing it. If you have cracked internal joints between frame and plaster and mastic that has split away from the wall, we can put it right.
Outdoor sealant needs dry, clean surfaces, so work on frames around The Folly is planned for dry weather. Let us know about access to all the frames, upstairs ones included.
We stand behind the work with a one-year guarantee.
- Location
- The Folly (AL4)
- Region
- Hertfordshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What happens on the day
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, carry out the job and tidy away. Most jobs take anything from an hour or two to a full day, depending on how many frames there are. In a small place like The Folly, access is normally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- First we look at every frame and agree the list.
- The old mastic is cut out and the surfaces cleaned back.
- We fit backing rod in deep gaps so the sealant is the right 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
- Clear the area around the work
- For indoor joints, keep the area dry beforehand if you can
- Tell us if parking is tricky
Ask for a quote
Want a quote for window mastic? Please phone 0345 464 0079 or drop us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
What the job involves on each surface
Window sills
Sills catch the water running down the glass, so the joints at each end and underneath matter. Each is cleaned out and resealed.
uPVC windows
The frame is cleaned with a product that will not harm the plastic, then the new bead is laid against the frame and the wall.
Landlord and commercial work in The Folly
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
How we quote for window mastic
There’s no set price list, because no two jobs are the same. What we look at:
- The number of rooms or windows
- The product the joint needs
- Working hours on commercial sites
- Whether there’s mould to deal with
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we’ll go through it with you.
What to tell us for a quote
When you call or email, it’s useful to know:
- The address or postcode of the job
- The rough size of the job
- If it’s domestic, commercial or a hotel
- Access, such as stairs, a lift or height
Getting a quote is simple: let us know what needs doing and where and its rough size. A few pictures by email make the job easier to understand, and we’ll take it from there.
Window mastic in The Folly: local notes
With historic houses such as Shaw's Corner (about 2 miles north-east) nearby, there’s older building stock in the area around The Folly as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as St Helen's Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as St Helen's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
The Folly is about 2 miles east of Harpenden, in Hertfordshire. We carry out window mastic for homeowners, landlords and businesses in The Folly and nearby. The Folly is one of 381 towns and villages in Hertfordshire we cover. Our London page covers work nearby (24 miles or so).
All of AL4 is within our area for window mastic. That includes homes and businesses on Folly Fields and Lower Luton Road and the roads around them. We also cover Lea Valley (1 mile west), Amwell (1 mile south), Mackerye End (1 mile north-west), Blackmore End (1 mile north) and Batford (1 mile west). Larger places within reach include Watford (11 miles south), Hemel Hempstead (8 miles south-west), Stevenage (8 miles north-east), St Albans (5 miles south), Welwyn Garden City (5 miles east) and Hitchin (9 miles north).
Local landmarks in The Folly
In The Folly, that means homes and buildings near Sir John Lawes School and The Cherry Trees pub. For rail, the closest station is Harpenden station, roughly 2 miles west of the centre. Other landmarks nearby include St Albans City Hospital (4.2 miles south) and Harpenden Museum (2.2 miles west). Green spaces nearby include Wheathampstead Local Nature Reserve.
FAQs for The Folly
Do you work for landlords with property near Harpenden station?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. You can call 0345 464 0079 or email us with the details for a clear quote.
Do you cover smaller places like The Folly?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do you remove the old sealant?
Yes. All of the old material is cut out and the joint cleaned before resealing.
Can you work on commercial sites?
Yes, regularly. Larger jobs can be planned room by room or area by area to suit the site.
Can resealing stop a draught around my window?
Yes, where the draught is at the frame edge. We find where the air is coming from before we reseal.
Will you leave a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
Do you have insurance?
Yes. We are fully insured.
Is there any odour?
Possibly a little. Any smell clears as the sealant cures, and ventilation helps.
Should I try it myself first?
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Why it’s worth doing now in The Folly
Once mastic fails, rain can get between the frame and the wall. Over time that can mean damp patches, damaged plaster and rotting timber. Resealing now is a small job by comparison. Around The Folly, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
No two jobs are quite the same, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
Why The Folly clients choose us
- Old sealant always removed completely
- Anti-fungal sanitary silicone in wet areas
- Rated 4.9 stars on Google
- Fully insured
Read what affects the cost or customer reviews.
What we are called out for in The Folly
Plenty of failed mastic was poorly applied in the first place. Mastic laid onto dusty, damp or crumbling surfaces never bonded as it should, so it comes away long before its time.
The problems people generally mention when they call include:
- Draughty joints inside around the window
- Damp patches on the reveal after heavy rain
- Leaking joints at the ends of sills
- Sealant in the wrong colour for the frame
Rented homes near Harpenden station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Before booking anyone
- How the surfaces are prepared before sealing
- What happens if they find a problem under the old sealant
- Whether VAT is included
- The length of the guarantee