Greater London · England
Morden New Build Mastic
Plot mastic for developers and snagging failed sealant in new homes in Morden, with a one-year guarantee on every job. Ask us for a quote.
- Leaking shower tray seals in a new home
- Cracked sealant around new window and door frames
- Kitchen sealant that has pulled off the wall
How we handle new build mastic in Morden
If your new home has a leaking shower seal, open skirting joints or untidy sealant, we can help. If you’re still within the builder’s snagging or warranty period, tell them first, and if it isn’t put right, get in touch with us. Typical jobs include gaps behind new kitchen upstands and plot mastic for developers ahead of handover, across windows & doors, kitchens and show homes.
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.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Morden (SM4, SM3, SW20)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What we do, step by step
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours for most snagging lists, longer for a run of plots, and the area is left clean. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Morden. A visitor permit or a nearby bay makes the visit run more smoothly.
- Each joint is checked for movement before work begins.
- Old sealant is cut out and the joints cleaned.
- Joints are dried and primed where the product calls for it.
- Baths are filled with water, then the new sealant is applied.
- We check every joint and leave you with the cure times.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Clear items away from the joints we are working on
- Where the joints are inside, avoid wetting them before we arrive
Ask for a quote
If you are in Morden and need new build mastic, call 0345 464 0079 or email us. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
Related advice
Towns and villages near Morden
Also in Morden
Why act early in Morden
A quick bead over the top of the old sealant can look fine at first, but it will not bond to the old layer. A lasting seal starts with removing the old one completely. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Morden, the repair is bigger than a sealant job.
The cost depends on the amount of work, how much old material has to come out and access to the work. We give a clear quote before we start, so you know where you stand.
What you get with us
- A choice of colours where the product allows
- Full insurance on every job
- Anti-fungal silicone where joints get wet
- 20+ years of sealant experience
Joints and finishes in Morden homes
Much of London’s new housing is flats in larger 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.
If you’ve bought a new home near St Helier station, the sealant around baths, showers and frames is worth checking in the first year or two.
Morden is about 2 miles south of Wimbledon, in Greater London. Anywhere in SM4, our applicators can take on new build mastic. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our London page, about 9 miles away.
Work in SM4, SM3 and SW20 is quoted and booked the same way as anywhere else. Whether your property is on London Road, Epsom Road and Holne Chase or anywhere close by, we can help. Main roads around Morden include the B279, which makes travel easy. Close by, we work in Lower Morden (1 mile south-west), Sutton Common (1 mile south-east), North Cheam (2 miles south), Worcester Park (2 miles south-west) and Stoneleigh (3 miles south-west). Within a short drive, we also cover London (9 miles north-east), City of Westminster (9 miles north), Marylebone (9 miles north), Kensington (7 miles north), St Pancras (10 miles north-east) and Shoreditch (11 miles north-east).
What’s near Morden
Typical jobs here are in homes near Lord Nelson pub, Glenthorne High School and Cannon Hill Common and the streets around them. Morden has its own railway station: St Helier station. Other landmarks nearby include St. Anthony's Hospital (1 mile south-west) and Chessington Castle Hill (4.3 miles south-west). Not far away are Henman Hill and Morden Park (park).
Different surfaces, different methods
Windows and doors
Internal joints between frames and plaster often crack as a new house dries. We remove cracked sealant and apply a flexible one in a matching colour.
Skirting and floors
Where the floor meets a bath panel or kitchen plinth, the joint keeps mop water out. We seal them with a sealant suited to wet areas.
Do you need new build mastic in Morden?
Sealant applied onto damp surfaces does not bond well. Site programmes do not always leave time for joints to dry first.
If you can see any of these, it’s time to have the joints looked at:
- Gaps behind new kitchen upstands
- Internal frame sealant that has split
- Smeared, uneven beads picked up at snagging
- Skirting joints opening in the first winter
Morden is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What your quote should include
- Whether you can choose the colour
- Whether the sealant suits the joint
- Is the old sealant removed completely?
- What guarantee comes with the work
Landlords, agents and businesses in Morden
Letting agents often deal with us directly. Tell us the address, the job and how access works and we will quote.
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
DIY versus a professional finish
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
What affects the cost of new build mastic
We don’t publish a price list, because jobs vary so much. What we look at:
- Whether the work is at height
- Working hours on commercial sites
- Any mould that needs treating
- The number and length of the joints
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- If it’s domestic, commercial or a hotel
- Any previous sealing or DIY work
- The rough size of the job
- What the problem is, such as mould, gaps, leaks or cracking
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we’ll talk you through the work before giving you a price.
Morden questions
Is Morden in your area for new build mastic?
Yes, Morden is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job.
I let a flat near St Helier station. Can you help?
Yes, we work for landlords and letting agents. Just phone 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear price.
How long should I leave it?
It depends on the product. We tell you how long to leave it before we go.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures, and ventilation helps.
Can you do several jobs on one visit?
Yes, and it often makes sense. Doing several areas at once is generally more efficient, so mention them when you ask for a quote.
Why has my new-build shower seal failed already?
There are generally two causes: movement as the house dries and settles, and sealant laid onto dust without primer. Cutting it out and resealing properly fixes both.
How long does the job take?
That depends on the amount of work, but most jobs take a few hours in a single home. We’ll tell you when we quote.
When is the best time to reseal in a new build?
Any seal that’s leaking should be redone right away. For small cosmetic gaps, waiting until the house has settled can save doing them twice.