Greater London · England
New Build Mastic in Sidcup
Our applicators work in Sidcup on plot mastic for developers and snagging failed sealant in new homes. Old sealant removed completely, joints prepared properly.
- Shower seals failing in the first year or two
- Gaps between new skirting and floors
- Sealant that never bonded to the surface
How the visit works
A visit follows a simple pattern: we check the joints, mask and protect the surrounding surfaces, do the work and tidy away. It normally takes a few hours in a single home. In a London area like Sidcup, the main things to plan are parking and access: let us know about parking, the floor we will 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.
- We apply a sealant that suits each joint and tool it to a neat finish.
- We check every joint and tell you how long each needs to cure.
Before we arrive
- Mention any leaks or damp you’ve noticed
- Try not to wet indoor joints just before the visit
- Mention any sign-in or site rules at work premises
Get a quote
Need a quote? Please phone 0345 464 0079 or email us with a few details. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
New build mastic in Sidcup
We work in new homes and on new-build sites across Sidcup. Whether it’s one en suite or a run of plots, the method is the same: cut out, clean, prime where needed and reseal neatly. If you’re dealing with second-fix sealing on new plots and new-build shower sealant that has already split, we can put it right, whatever the surface.
Much of London’s new housing is flats in larger developments. In a new development, snags are often reported through the developer or the managing agent, and shower seals that fail early, skirting joints that open up and gaps at thresholds are all common snags.
You get a 12-month guarantee, the same in Sidcup as everywhere else we work.
- Place
- Sidcup (DA14, DA15, SE9, DA5)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens if it’s left?
DIY kits don’t solve the main problems with new-build sealant: dust, no primer and old sealant left in the joint. Proper removal and preparation are what make it last. 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.
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs, plus any working-time requirements on site. Ask us for a quote and we will explain what it covers.
Why us?
- Full insurance on every job
- Over 20 years’ experience
- We never seal over old sealant
- Homes, businesses and hotels
See what affects the cost or our reviews.
Also near Sidcup
More services for Sidcup
New build mastic in Sidcup: local notes
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Many of London’s new homes are flats in bigger developments, where snagging may go through the developer or managing agent.
If you’ve bought a new home near Sidcup station, the sealant around baths, showers and frames is worth checking in the first year or two. As a London address, Sidcup can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Sidcup is about 3 miles north of Orpington, in Greater London. If you need new build mastic in Sidcup, please call 0345 464 0079 or email us for a quick quote. We cover Greater London from our Crawley base, Sidcup included. Our Greater London coverage runs to 764 places, Sidcup among them. We also work in London, about 10 miles from Sidcup.
All of DA14, DA15, SE9 and DA5 is covered for new build mastic. We cover properties on Station Road, High Street and Jubilee Way and the roads around them. Sidcup is on the A211 and A2001, which makes it straightforward to reach with everything needed for new build mastic. Close by, we work in Albany Park (1 mile south), Blendon (1 mile north-east), Foots Cray (1 mile south-east), Bexley (2 miles north-east) and North Cray (2 miles east). Further out, we also cover London (10 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (14 miles west), St Pancras (11 miles north-west) and Shoreditch (10 miles north-west).
Near you in Sidcup
Typical jobs here are in homes near The Alma pub, Waring Park and Chislehurst and Sidcup Grammar School and the streets around them. Sidcup has its own railway station: Sidcup station. A little further out are Queen Mary's Hospital (1 mile south) and Broadway Shopping Centre (2.4 miles north-east). Open spaces near Sidcup include Summer Hill and The Tarn.
What sealant work cannot fix
A few problems are outside what sealant work can do:
- Deciding who is responsible under a builder’s warranty
- Plumbing faults behind the sealant
- Broken tiles or a split tray
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think.
Where we work in Sidcup
- Show homes
- Bathrooms & en suites
- Kitchens
- Plot handovers
- Windows & doors
- Skirting & floors
Aftercare tips
A little care helps the new joints last. Our advice:
- Do not seal over failed sealant yourself
- Open a window or run the fan after bathing
- Keep water off fresh sealant until it has cured
- Keep pictures and emails about snagging items
Avoid standing on the rim of the bath or the edge of the tray. If a bath or tray moves when you stand in it, get it looked at.
If a shower tray or bath seal splits in the first year, look for movement. Have it resealed, and the tray or bath checked, before it gets worse.
Work for landlords, hotels and businesses
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
Hotels need rooms back in use, so we plan the work room by room around your bookings where we can. We have worked in hotels as well as homes and businesses.
Questions from Sidcup
Is parking a problem for a job in Sidcup?
Parking in Sidcup, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Is Sidcup in your area for new build mastic?
Yes, Sidcup is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job.
What information do you need?
A short description and the location, plus photos if you have them. We will ask anything else we need to know.
Do you take out the old sealant first?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Will you just run a new bead over the existing one?
No. We always remove the existing bead, then clean and prime the joint, before resealing.
Will you leave a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
I’m a tenant. Can you help?
Yes, though it’s best to check with your landlord first. Many landlords are glad to have it sorted.
Should I try DIY first?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
What affects the cost of new build mastic
For a quick quote, just ask. The main things that affect it are:
- The number and length of the joints
- Which sealant suits the joint
- The old material and how stubborn it is
- How many areas need sealing
Doing several joints on one visit generally makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll send you a clear quote for the lot.
What to tell us for a quote
When you call or email, it’s useful to know:
- Roughly how big the job is
- What the problem is, such as mould, gaps, leaks or cracking
- Access, such as stairs, a lift or height
- Whether it has been sealed before
Asking for a quote is easy: let us know what needs doing and where. Photos by email help us understand the job.
DIY sealant or a professional job?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
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 doesn’t work out, we can still put it right.