Greater London · England
New-build mastic & snagging in Clapham, Greater London
Our applicators work in Clapham on plot mastic for developers and snagging failed sealant in new homes. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- Cracks appearing as a new home settles
- Untidy sealant flagged on a snagging list
- Sealant that never bonded to the surface
About our new build mastic in Clapham
In a new home, every joint should have a clean, even bead. Smeared, patchy or cracked sealant is worth sorting early, before water gets into the floor or walls. We are often asked to deal with sealant work across a run of new homes and frame joints opening as the plaster dries, on show homes, kitchens and bathrooms & en suites.
Shops, offices and commercial units across London have hard-wearing floors with movement joints that need resealing as they wear, while new homes need a neat, sound finish around frames, baths and kitchens before handover.
You get a 12-month guarantee, the same in Clapham as everywhere else we work.
- Location
- Clapham (SW4, SW8, SW9)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
How we quote for new build mastic
We quote each job individually. These are the things that affect it:
- The number and length of the joints
- Whether old sealant or filler has to be cut out
- The product the joint needs
- Whether the work is at height
What you pay reflects the work, not guesswork. That’s why we ask a few questions first.
What we need to know
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Any access issues, like height or stairs
- The type of property
- Pictures of the joints, sent by email
- Where the job is, and your postcode
Need a quote? Please phone 0345 464 0079 or send us an email and tell us about the job. We will explain what we’d do and give you a clear price before any work starts.
Signs you need new build mastic in Clapham
The first winter with the heating on dries a new home quickly. Gaps open along skirting, frames and worktops.
People usually contact us after spotting one of these:
- Plot mastic for developers ahead of handover
- Untidy sealant flagged on a snagging list
- New-build shower sealant that has already split
- Gaps between new skirting and floors
If you’ve bought a new home near Clapham High Street station, the sealant around baths, showers and frames is worth checking in the first year or two.
Comparing quotes
- What insurance they hold
- Is the old sealant removed completely?
- What product goes in the joint
- When the joint can take water or movement
Clapham questions
Is parking a problem for a job in Clapham?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Can you help a landlord with a rental near Clapham High Street station?
Yes. We work for landlords and agents as well as homeowners, and several properties can be quoted together. You can ring 0345 464 0079 or email us with the details for a clear quote.
Is there any odour?
There can be a smell while the sealant cures. Ventilation helps.
Where are you based?
Mr Mastic is based in Crawley. Our applicators cover Clapham.
How long will you be here?
Typically it takes a few hours in a single home. Larger jobs naturally take longer, and we’ll say how long yours will take.
Does someone need to be in?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
Do you do commercial work?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
Can you reseal over the builder’s sealant?
No. The old sealant is cut out fully, then clean and prime the joint, before resealing.
New homes and floors in Clapham
Many of London’s new homes are flats in bigger developments, where snags may need reporting through the developer or the managing agent. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Clapham is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Clapham is about 3 miles north of Streatham, in Greater London. We carry out new build mastic for homes and businesses in Clapham and the surrounding area. Our area takes in 764 places across Greater London.
We cover every part of SW4, SW8 and SW9 for new build mastic and the streets around it. Streets in the area include Grafton Square, Clapham High Street and Houghton Square, and we cover them all. Main roads around Clapham include the B224 and B303, so getting to you is simple. If you’re just outside Clapham, we cover Stockwell (1 mile east), Little Portugal (1 mile north-east), Clapham Park (1 mile south), South Lambeth (1 mile north-east) and Brixton (1 mile south-east). Further out, we also cover London (3 miles north-east), City of Westminster (3 miles north), Marylebone (4 miles north), Kensington (4 miles north-west), St Pancras (4 miles north) and Shoreditch (5 miles north-east).
Near you in Clapham
We work in homes and buildings around Lambeth Academy, Larkhall Park and Trinity Academy, among other places. There’s a railway station in Clapham itself: Clapham High Street station. Well-known places in the area include Baynard's Castle (3.5 miles north-east) and Harrods (2.6 miles north-west). Not far away are Battersea Park Lake and Knight's Hill.
Aftercare tips
A little care helps the new joints last. We recommend:
- Watch for new gaps as the house dries out
- Act quickly if a seal starts to leak
- Put sealant faults on your snagging list early
- Open a window or run the fan after bathing
Photograph failed sealant before it’s redone and keep the builder’s replies. It’s useful if you need to raise other issues later.
Mould takes hold quickly in sealant that has gaps or lifted edges. Resealing before mould gets in saves a harder job later.
What happens on the day
We bring everything the job needs with us, so there’s nothing for you to buy. Once we’ve agreed what’s being done, the area is protected and the work begins. It normally takes a few hours in a single home. For a job in Clapham, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- First we work through your snagging list or plot schedule with you.
- The old bead comes out in full, with no layer left behind.
- Each joint is cleaned of dust and grit, then primed if required.
- New sealant suited to each joint is applied and tooled neatly.
- Each area is checked and left with its cure time.
Preparing for the visit
- Mention any leaks or damp you’ve noticed
- Keep children and pets away from the work area
- Mention any tricky access
Get a quote
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 will come back to you with a quote.
Read more
Honest limits
In fairness, there are a few things sealant will not fix:
- Deciding who is responsible under a builder’s warranty
- Leaking fittings rather than failed sealant
- Broken tiles or a split tray
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before you book.
Where we work in Clapham
- Kitchens
- Skirting & floors
- Bathrooms & en suites
- Show homes
- Windows & doors
- Plot handovers
Towns and villages near Clapham
What else we do in Clapham
What the job involves on each surface
Skirting and floors
Floors and skirting move as the house dries and the heating runs. We use a flexible product rather than caulk.
Show homes
Bathrooms, kitchens and frames in show homes are sealed or resealed to a neat finish ready for viewings. We will plan around viewing times.
Leave it or put it right?
Water getting past a failed seal in a new build reaches walls and floors that are still settling. Dealing with it early keeps the damage away from ceilings, floors and finishes. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Dealing with it early is far simpler for homes in Clapham.
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all play a part, and we’ll explain the quote if you ask.
What you get with us
- Full insurance on every job
- ARBOMaster approved applicator
- Experience in homes, commercial sites and hotels
- Sealant colour chosen to suit
Take a look at our cost guide or customer reviews.