Portsmouth · England
Remedial sealant & repairs in Cosham, Portsmouth
Removing failed, mouldy or leaking sealant and putting it right for Cosham, backed by a 12-month guarantee. Call for a quick quote.
- Dark patches showing through the sealant
- Torn expansion joints
- Sealant peeling off a dusty or damp surface
Remedial sealant in Cosham
Not every leak is a sealant leak. Cracked trays, leaking wastes and faulty valves often look like a sealant problem. When the fault is elsewhere, we say so instead of resealing for the sake of it. If you’re dealing with smears and lumps from a botched reseal and sealant peeling off a dusty or damp surface, we can put it right.
Even in a smaller place like Cosham, bathrooms and kitchens see heavy daily use. Whether it’s a cottage bathroom or a newer en suite, the approach is the same: all the old material out, the joint cleaned and dried, then new sealant or grout.
We stand behind the work with a 12-month guarantee, so you’re not left on your own once the job is done.
- Where
- Cosham (PO6, PO3, PO2)
- Wider area
- Portsmouth
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Different surfaces, different methods
Worktops & kitchens
If a worktop moves when you lean on it, the sealant will keep splitting. It needs fixing down first, which we’ll point out.
Mouldy bath & shower sealant
Repeat mould usually points to a damp, poorly aired room. Along with resealing, we will mention if the room needs better ventilation.
Why act early in Cosham
Hidden water does the most damage: wet floors, stained ceilings and swollen worktops. Dealing with the joint now is a small job by comparison. Around Cosham, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
What you get with us
- ARBOMaster approved applicator
- Sealant colour chosen to suit
- Old sealant always removed completely
- White, clear, grey or another colour, product permitting
Also near Cosham
More services for Cosham
Bathrooms and kitchens in Cosham
Cosham is close to the coast. Near the coast, holiday lets and guest houses can see bathrooms used by one guest after another, and sealant and grout that work that hard wear out sooner. 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 Cosham station, botched sealant from a previous quick fix is easier to strip out between tenants. For site and facilities teams at buildings such as Court Lane Junior Academy, its toilets, changing areas and kitchens need their sealant renewed like any other building’s.
Cosham is about 2 miles south-west of Purbrook, in Portsmouth. Anywhere in PO6, we can carry out remedial sealant at your property. Cosham is one of 19 towns and villages in Portsmouth where we work for remedial sealant.
Our applicators cover all of PO6, PO3 and PO2 for remedial sealant. Local streets include Dean Road, Park Lane and Elgin Road, and we cover them all. You’ll find Cosham on the A397, so it’s easy for us to get to. Neighbouring places we cover for remedial sealant include Wymering (1 mile north-west), Hilsea (1 mile south), Drayton (1 mile east), Widley (1 mile north-east) and Paulsgrove (1 mile west). Within a short drive, we also cover Southsea (4 miles south), Milton (3 miles south), Landport (3 miles south), Portsea (3 miles south-west), Portsmouth Point (4 miles south-west) and Fratton (3 miles south).
Around Cosham
Locally, jobs take us to homes and businesses close to The First Post pub, Alexandra Park and Springfield School, among other places. There’s a railway station in Cosham itself: Cosham station. A little further out are Tricorn Centre (2.9 miles south) and World War I Remembrance Centre (1 mile south-east). Green spaces nearby include Southmoor Nature Reserve and Portsdown Hill.
Cosham: your questions answered
Do you cover smaller places like Cosham?
Yes, we do. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Do you work for landlords with property near Cosham station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we will give you a clear quote.
What do you need from me for a quote?
A short description and the location. We’ll ask anything else we need to know.
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.
What does remedial sealant cost?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you do not need to watch us work.
Are you insured?
Yes. Mr Mastic is fully insured, and we have been doing sealant work for more than 20 years.
Is it worth trying it myself?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. If it doesn’t work out, we can redo it.
DIY versus a professional finish
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
How it works
On the day, there’s very little for you to do. Show us the job and we will take it from there. The work itself takes a few hours for most joints, depending on how much old sealant has to come out, including the tidy-up. In a smaller place like Cosham, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- We protect the surfaces around the joint.
- Every layer of failed sealant is stripped out.
- The joint is degreased and checked for movement and leaks.
- New sealant goes in once the joint is dry, and is tooled smooth.
- We give you the cure time and explain what caused the failure.
Preparing for the visit
- Let us know about earlier repairs to the joints
- Clear the area around the work
- Tell us about any water getting in
Ask for a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or send us an email.
Related advice
When it is not the sealant
A few problems are outside what sealant work can do:
- Plumbing leaks behind walls or under trays
- Older mastics that may need an asbestos check before removal
- Cracks in the fitting rather than the joint
If you are not sure, just phone 0345 464 0079 or send us an email and we’ll give you a straight answer before booking.
Surfaces we seal
- Mouldy bath & shower sealant
- Shrunken worktop sealant
- Failed movement joints
- Expansion joints
- Leaking tray & enclosure joints
- Botched or over-sealed joints
Do you need remedial sealant in Cosham?
Sealant needs a clean, dry surface with no grease on it. Soap film, dust, damp or old residue stop it gripping, and the joint starts to come away early.
Common reasons people contact us include:
- Floor or wall movement joints that have failed
- Beads that never stuck properly
- A shower that leaks however often it’s resealed
- Thick, messy sealant smeared over tiles
For an older house near a landmark such as Church of St Philip, bathrooms in older houses have often been refitted more than once, with sealant laid over sealant.
Comparing quotes
- How the surfaces are prepared before sealing
- What happens if they find a problem under the old sealant
- When the joint can take water or movement
- Are they insured?
Aftercare tips
So the new joints stay in good condition:
- Check trays and worktops don’t move
- Get the cause of a repeat leak found before resealing
- Don’t wait for a small gap to become a leak
- Keep bleach and abrasives off the bead
Where we’ve pointed out another fault, have it put right, or the new joint may fail again.
A split movement joint lets rain into walls and floors, and the longer it’s left, the more the joint edges break down. A joint with sound edges is far easier to reseal.