Greater London · England
Silicone replacement in South Harefield
Removing failed, mouldy or leaking sealant and putting it right in South Harefield, with a 12-month guarantee on every job. Ask us for a quote.
- Sealant that came away because the surface wasn’t prepared
- Leaks that keep coming back after resealing
- Thick, messy sealant smeared over tiles
Remedial sealant in South Harefield, done properly
Two decades of sealant work means we recognise most failures quickly. We are ARBOMaster approved and fully insured, and every remedial job comes with a 12-month guarantee. If you have sealant peeling off a dusty or damp surface and gaps opening along the back of the worktop, we can put it right. As mastic and silicone sealant specialists, we take on remedial sealant and every other kind of sealant job in South Harefield.
Much of London’s older housing is Victorian and Edwardian terraces, many of them now split into flats, and bathrooms were often squeezed into small rooms. Small, steamy rooms are where mould gets into sealant and grout fastest, and homes in South Harefield are no different.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Place
- South Harefield (UB9)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 07833 053749
- Page updated
- 26 October 2026
For landlords and businesses
We also work for property managers and facilities teams in South Harefield and across Greater London. We can quote a run of properties together, and we’re fully insured for the work.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
What we do, step by step
When we arrive, we start by going over the job with you. Surfaces next to the work are protected before any work begins. Most jobs take a few hours for most joints, depending on how much old sealant has to come out. For a job in South Harefield, parking and access are the things to plan: let us know about parking, the floor we will be working on and any lift or shared entrance.
- The failure is looked at first, so we know whether it’s sealant, movement or water from elsewhere.
- Each layer is cut out and the residue cleaned off.
- We treat any mould and dry the joint thoroughly.
- We reseal with a product suited to the joint, backed where needed.
- We finish neatly and point out anything that needs another trade.
Before we arrive
- On commercial sites, let us know about site rules
- Let us know if you’ve seen damp or leaks
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. Whenever you are ready, phone 07833 053749 or email us.
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Leave it or put it right?
A failed seal rarely means a new bathroom. When the fittings are sound, stripping and resealing the joints is often enough. If they’re not, we will tell you. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in South Harefield, the repair is bigger than a sealant job.
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. Ask us for a quote and we will explain what it covers.
Why us?
- Any old sealant cut out fully, not covered over
- Domestic, commercial and hotel work
- We agree the colour with you first
- ARBOMaster approved applicator
Read our cost guide and what customers say.
What affects the quote in South Harefield
Your quote is based on your job. We take into account:
- Any working-time requirements on site
- How much there is to do
- The product the joint needs
- How much old sealant there is and how hard it is to remove
What it costs depends on how much there is to do, how hard the old material is to remove and access to the work. We give a clear quote before any work starts, so you know where you stand.
What to tell us for a quote
When you contact us, these details help:
- Where the property is
- The type of property
- Any access issues, like height or stairs
- Photos by email, if that’s easy
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved before giving you a price.
Towns and villages near South Harefield
Also in South Harefield
Common questions in South Harefield
I let a flat near Denham station. Can you help?
Yes, we work for landlords and agents. Just call 07833 053749 or drop us an email and tell us about the property, and we’ll send you a clear quote.
I live in a flat in South Harefield. Can a failed seal leak into the flat below?
Yes, and the first sign is often a stain on the ceiling below. Cutting out the old sealant and laying a new bead early stops it getting that far.
How long should I leave it?
That depends on the sealant used, so please follow the time we give you.
Where is Mr Mastic based?
Our base is in Crawley, and we work across South East England, London and Scotland.
Do I need to be at home?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
How long does the work take?
That depends on how many layers there are and how many joints. You will have a timescale before any work begins.
Do the sealants smell?
That depends on the sealant. Some smell for a while, some hardly at all.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Surface by surface
Over-sealed & botched joints
Previous removal attempts can leave scratches or gouges. We take care not to make it worse, and tell you about any damage we find.
Leaking trays & enclosures
Repeat shower leaks often come from a tray that flexes or an enclosure sealed in the wrong place. We check both before any new sealant goes on.
Remedial sealant around South Harefield
London has a lot of flats and conversions, and a failed shower or bath seal in one can show up on the ceiling below, so tired sealant is best dealt with early. London has hard water, which leaves limescale on sealant, grout and taps, and it has to be cleaned off before new sealant goes in.
South Harefield is in London, so parking needs planning: let us know about parking bays, permits or a driveway. Schools such as Harefield Infant School are buildings too, and we reseal washrooms and kitchens in schools and businesses as well as homes. For an older house near a landmark such as Church of St Mary the Virgin, walls and floors in older homes can move, and sealant and grout show it first.
South Harefield is about 3 miles west of Ruislip, in Greater London. For remedial sealant in and around South Harefield, please call 07833 053749 or send us an email for a quick quote. We’re based in Crawley and cover Greater London. 786 places in Greater London are on our list, large and small.
Our applicators cover all of UB9 for remedial sealant. Local streets include Peerless Drive, Truesdale Drive and Priory Avenue, and we cover them all. Other places close to South Harefield include Newyears Green (1 mile south-east), Denham (2 miles south), New Denham (3 miles south), Ickenham (3 miles south-east) and Ruislip Manor (3 miles east). Larger places within reach include City of Westminster (15 miles east), Marylebone (15 miles east), Kensington (14 miles south-east), Hampstead (13 miles east), Brompton (15 miles south-east) and Ealing (9 miles south-east).
Local landmarks in South Harefield
We work in homes and buildings around The River Garden pub, The Harefield Academy and The Green. For rail, the closest station is Denham station, roughly 1 mile south-west. Other landmarks nearby include The Pavilions (3 miles south) and Hillingdon Museum and Archives Services (3.1 miles south). Green spaces nearby include Horse Shoe Bay and Dews Farm Sand Pits.
DIY versus a professional finish
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
Looking after it afterwards
Aftercare is simple, and it makes a real difference:
- Keep the room well ventilated
- Use a soft cloth, not a scourer, on silicone
- Don’t wait for a small gap to become a leak
- Always have old sealant cut out, not covered
Go easy on the new sealant: a mild cleaner and a soft cloth, with no blades or scourers.
Mould trapped under over-sealed joints spreads unseen. By the time it shows through, the joint is well past saving.