Hertfordshire · England
Remedial Sealant in Astwick
Removing failed, mouldy or leaking sealant and putting it right for householders, landlords and businesses in Astwick. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Black mould underneath the bead
- Caulk or the wrong sealant used in a wet area
- Wide, uneven beads that look worse than the old ones
Can I do it myself?
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
Remedial sealant in Astwick
A movement joint stops working when its sealant splits or sets hard. The old sealant comes out and backing goes in to control the depth, then a flexible sealant matched to the movement goes in. We work on expansion joints, shrunken worktop sealant and botched or over-sealed joints, and people most often call us about movement joints that have split or pulled away and sealant peeling off a dusty or damp surface.
Around Astwick, it’s houses and cottages rather than flats, some with bathrooms tucked into older rooms or extensions. The work is the same as anywhere: old material cut out, joints cleaned and a fresh finish laid.
All our work is covered by our one-year guarantee.
- Place
- Astwick (SG5)
- Wider area
- Hertfordshire
- Guarantee
- A year, on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Common problems we fix in Astwick
Movement tears sealant that isn’t designed for it. A bath that flexes, a tray that rocks or a building joint that opens and closes split any bead that’s too stiff or too thin.
Any of these means the joints need attention:
- Floor or wall movement joints that have failed
- Wide, uneven beads that look worse than the old ones
- Sealant applied over old sealant that has lifted
- Gaps opening along the back of the worktop
If you live in an older home near Church of Saint Guthlac, walls and floors in older homes can move, and sealant and grout show it first.
What to look for in a quote
- What happens if they find a problem under the old sealant
- Whether they’re fully insured
- Whether all the old sealant comes out first
- When the joint can take water or movement
Remedial sealant in Astwick: local notes
Hard water is the norm across most of the South East, so limescale builds up on sealant, grout and fittings.
If you let a flat or house near Arlesey station, a joint that keeps failing is best fixed properly while the property is empty. For site and facilities teams at buildings such as St Mary's CofE Academy Stotfold, we reseal washrooms and kitchens in schools and businesses as well as homes.
Astwick is about 1 mile north of Stotfold, in Hertfordshire. Homes, rented property, offices and hotels in Astwick is covered for remedial sealant, old or new, large or small. The work is guaranteed for a year. 381 places in Hertfordshire are on our list. For nearby work, see our London page (37 miles or so).
Postcode districts we cover here for remedial sealant: SG5. We cover properties on Astwick Road and Sycamore Avenue and the roads around them. Neighbouring places we cover for remedial sealant include Stotfold Common (1 mile south), Stotfold (1 mile south) and Radwell (2 miles south-east). We also work in nearby towns such as Stevenage (9 miles south), Hitchin (6 miles south), Letchworth (4 miles south), Letchworth Garden City (4 miles south), Baldock (4 miles south-east) and Benslow (6 miles south).
Near you in Astwick
The nearest railway station is Arlesey station, roughly 1.5 miles west. Nearby you will also find Fairfield Hospital (2.2 miles south) and Bygrave House (3.6 miles south-east). Not far away are Arlesey Old Moat and Glebe Meadows.
Quotes for remedial sealant in Astwick
We quote each job individually. This is what makes a difference:
- When we can work, for business premises
- Any mould that needs treating
- How much there is to do
- The number of rooms or windows
A failed joint rarely gets cheaper to fix by waiting. If you are unsure, call 0345 464 0079 or drop us an email and we will give you an honest view and a quote.
Asking for a quote
To help us quote quickly, please include:
- Access, such as stairs, a lift or height
- Pictures of the joints, sent by email
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
If you are in Astwick and need remedial sealant, call 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before we start.
When it isn’t the sealant
New sealant cannot fix everything, and we will tell you before any work starts. Sealant won’t put right:
- A tray or bath that is cracked
- Older mastics that may need an asbestos check before removal
- A tray or worktop that needs refixing first
If you are not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer before you book.
What we seal
- Botched or over-sealed joints
- Shrunken worktop sealant
- Expansion joints
- Failed movement joints
- Mouldy bath & shower sealant
- Leaking tray & enclosure joints
What happens on the day
When we arrive, we look over the joints with you first, so you know exactly what we’re doing. We protect the surfaces around the joints before any work begins. Most jobs take a few hours, depending on how many layers have to come out. Somewhere as small as Astwick, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by checking the joint for movement, leaks and the reason it failed.
- We strip the joint completely, removing any layers below.
- We clean the joint, treat any mould and let it dry.
- We use the right backing and sealant for any joint that moves.
- Finally we finish the joint and talk you through what we found.
Preparing for the visit
- Tell us if parking is tricky
- Clear the area around the work
- Mention if the joints have been sealed before
Ask for a quote
To get a quote, ring 0345 464 0079 or send us an email with the location and a short description of the problem. We will give you a clear price before any work starts.
Related advice
Nearby places to Astwick
What else we do in Astwick
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Have loose fittings fixed before resealing
- Keep bleach and abrasives off the bead
- Keep movement joints clear of mortar and paint
- Don’t wait for a small gap to become a leak
If the joint ever needs renewing, have it cut out, not sealed over. New silicone does not bond to old, so the old bead should always come out first.
Don’t keep resealing the same joint. Get the cause found first, or the next bead will go the same way.
FAQs for Astwick
Do you cover Astwick for remedial sealant?
Yes. Our work covers London and the South East, and Astwick is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing.
Is Astwick within the area you cover?
Yes, we do. We work across London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
Can you remove old sealant without damaging the bath?
Yes. Residue is removed with a product suited to the surface rather than scraped hard.
Are you fully insured?
Yes. We are fully insured for every job we do.
Where are you based?
Mr Mastic is based in Crawley. Our applicators cover Astwick, along with the rest of our area.
Do you work for letting agents?
Yes, regularly. Several properties can go on one quote.
What if resealing won’t fix my leak?
We’ll tell you. A cracked tray, faulty valve or leaking waste needs a different trade, and we will not reseal for the sake of it.
How do I get a quote for remedial sealant in Astwick?
It depends on the job, so we quote each one individually. For a quick quote, ring 0345 464 0079 or email us and let us know what needs doing and where.
What happens if it’s left?
Adding more sealant is the usual quick fix, and it rarely works. It cannot bond to what’s underneath, so the leak carries on and there’s now more to remove. Where a wall is exposed, as many are in small places like Astwick, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
We don’t show prices on the website, because each job is priced on what it involves. Call for a quick quote.
Why us?
- Quality sealants from Arbo and Everbuild
- More than 20 years in sealant work
- You choose the colour before work begins
- Fully insured