Greater London · England
New Build Mastic in Swiss Cottage
Problem with your new-build sealant joints in Swiss Cottage? We cut out the old, prepare the joints and apply the right sealant, with a 12-month guarantee.
- Shower seals failing in the first year or two
- Cracked caulk along new skirting
- Sealant work across a run of new homes
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 chosen for how the joint moves and where it is, and the work is guaranteed for a year.
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.
New build mastic in Swiss Cottage, done properly
A new build should have a neat, sound bead at every joint. When the finish is smeared, patchy or already cracking, it’s worth putting right early, before water gets into the floor or walls. We work on bathrooms & en suites, plot handovers and kitchens, and the jobs we see most are sealant work across a run of new homes and leaking shower tray seals in a new home.
From brand-new flats to converted terraces with new flooring, London has every kind of floor. Wherever a floor meets a wall, a skirting or a threshold, the joint has to allow for movement.
Every job is covered by our 12-month guarantee, wherever you are in Greater London.
- Where
- Swiss Cottage (NW3, NW8, NW6)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What new build mastic looks like in Swiss Cottage
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For new homes near South Hampstead station, it’s worth checking the sealant early, while snags are still fresh.
Swiss Cottage is about 1 mile south of Hampstead, in Greater London. If you need new build mastic in Swiss Cottage, please call 0345 464 0079 or email us for a quick quote. We cover Greater London from our Crawley base. Our area takes in 764 places across Greater London, large and small.
Every address in NW3, NW8 and NW6 is within our area for new build mastic, from the main roads to the quietest streets. Local streets include Avenue Road, Acacia Road and Harben Road, all of which we cover. We also cover the places around Swiss Cottage: South Hampstead (1 mile north), St John's Wood (1 mile south), Haverstock (1 mile east), Belsize Park (1 mile east) and Primrose Hill (1 mile east). Further out, we also cover London (4 miles south-east), Kensington (3 miles south-west), St Pancras (3 miles south-east), Shoreditch (4 miles east), Walthamstow (7 miles north-east) and Hoxton (4 miles east).
Landmarks near Swiss Cottage
Locally, jobs take us to homes and businesses close to Cafe Med pub, Holy Trinity CofE Primary School and Primrose Hill, among other places. Nearby too are Cecil Sharp House (1.1 miles east) and St. Mary's Town and Country School (under half a mile north-east). There’s a railway station in Swiss Cottage itself: South Hampstead station. Other landmarks nearby include Montfichet's Tower (3.7 miles south-east) and Isokon Gallery (0.8 miles north-east). The countryside around Swiss Cottage includes The Long Water and Primrose Hill.
Swiss Cottage questions
Can parking be tricky for a visit in Swiss Cottage?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Do you work for landlords with property near South Hampstead station?
Yes, we work for letting agents and landlords. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will send you a clear quote.
Should I wait before resealing?
For failed seals that let water through, the best time is now. Cosmetic gaps can wait until the first year or two of movement has passed.
Where are you based?
We work from Crawley. Our applicators cover Swiss Cottage, along with the rest of our area.
Do you work for developers?
Yes. We take on second-fix sealant work across new plots. We clean and prime joints properly to keep callbacks down.
Can you match the sealant colour to my new kitchen or bathroom?
That depends on what the joint meets: white or clear for most sanitary joints, colours for worktops, floors and frames. We agree the colour before any work starts.
Is there a guarantee?
Yes. All our work carries our 12-month guarantee.
Do you do commercial work?
Yes, regularly. We can plan bigger jobs in stages to suit the site.
How it works
Before we leave, we go over the finished joints with you. The work normally takes a few hours in a single home, depending on how much there is to do. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at why each joint failed, including any movement.
- We remove the failed sealant and clean the joints.
- Joints are dried and primed where the product calls for it.
- Baths are filled with water, then the new sealant is applied.
- The finished joints are checked and the cure times given.
Before we arrive
- Mention any sign-in or site rules at work premises
- Clear items away from the joints we are working on
- Let us know about parking restrictions
Getting a quote
Asking for a quote is easy: tell us what needs doing and where. A few photos by email make the job easier to understand.
Read more
Common problems we fix in Swiss Cottage
A new house holds a lot of water from the build, which takes a year or two to dry out. Drying timber shrinks and pulls joints apart and the sealant has to cope with the movement.
Common reasons people contact us are:
- Leaking shower tray seals in a new home
- Cracked sealant around new window and door frames
- Joints pulling apart as timber shrinks
- Cracked caulk along new skirting
Swiss Cottage is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What your quote should include
- Whether they’re fully insured
- Whether VAT is included
- Who does the work, and how experienced they are
- When the joint can take water or movement
Nearby places to Swiss Cottage
Other services in Swiss Cottage
How we quote for new build mastic
There’s no set price list, because no two jobs are the same. What we look at:
- Whether old sealant or filler has to be cut out
- How many areas need sealing
- The type of sealant required
- Whether the work is at height
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Ask us for a quote and we’ll go through it with you.
What we need to know
Photos by email are helpful but not essential. Try to tell us:
- Where the job is, and your postcode
- What’s wrong with the joints now
- The type of property
- Access, such as stairs, a lift or height
We quote each job on its own, so the first step is telling us about yours. Simply phone 0345 464 0079 or drop us an email and describe the job, and photos are welcome.
When it is not the sealant
A few problems are outside what sealant work can do:
- Structural cracks in walls or ceilings
- Leaks from pipes, valves or wastes, which need a plumber
- Baths and trays that move too much for sealant to cope with
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly.
Where we work in Swiss Cottage
- Bathrooms & en suites
- Show homes
- Skirting & floors
- Kitchens
- Windows & doors
- Plot handovers
Why deal with it now?
A hairline gap at a skirting can wait, but a leaking seal cannot. If you are unsure which you have, ring 0345 464 0079 or drop us an email with photos and we will tell you. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
The cost depends on how much there is to do, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts.
Why Swiss Cottage clients choose us
- An ARBOMaster approved applicator
- A choice of colours where the product allows
- More than 20 years in sealant work
- Homes, businesses and hotels
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Resist patching a failed seal with a tube from the DIY shop
- Keep pictures and emails about snagging items
- Do not wait for the house to settle if water is getting through
- Follow the cure time we give you
Leave the sealant for the cure time we give you before showering or bathing. Silicone is generally left for about a day.
Mould takes hold quickly in sealant that has gaps or lifted edges. Dealing with it before it goes black saves a harder job later.