Greater London · England
Dulwich New Build Mastic
We cover Dulwich for plot mastic for developers and snagging failed sealant in new homes. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Smeared, uneven beads picked up at snagging
- New-build shower sealant that has already split
- Joints pulling apart as timber shrinks
About our new build mastic in Dulwich
We never seal over a failed new-build bead. Fresh silicone cannot bond to the old layer, so it all comes out before we clean, dry and reseal. We work on skirting & floors, windows & doors and plot handovers, and people most often call us about gaps behind new kitchen upstands and beads laid onto grit and dust from the build.
Across London, commercial floors have movement joints that break down under heavy foot traffic, 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.
- Location
- Dulwich (SE22, SE21, SE23)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What sealant work can’t fix
We will not take on work that will not last, so here’s what sealant cannot put right:
- Damaged fittings that need replacing
- Your warranty claim itself, which is between you and the builder
- Cracking that points to a structural problem
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 Dulwich
- Windows & doors
- Show homes
- Skirting & floors
- Kitchens
- Bathrooms & en suites
- Plot handovers
Dulwich questions
Is parking a problem for a job in Dulwich?
Parking in Dulwich, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Is Dulwich in your area for new build mastic?
Yes, Dulwich is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Should I wait before resealing?
Any seal that is leaking should be redone straight away. Cosmetic gaps can wait until the first year or two of movement has passed.
How long will you be here?
A typical job takes a few hours for most snagging lists, longer for a run of plots, including the preparation. We’ll confirm how long when we quote.
Can tenants book the work?
We are happy to deal with the tenant, landlord or agent. Just make sure your landlord agrees.
Is it messy?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Do you work for letting agents?
Yes. As well as householders, we work for landlords, agents, businesses and hotels in Dulwich.
What happens if it’s left?
A hairline gap at a skirting can wait, but water getting through can’t. If you’re unsure which you have, ring 0345 464 0079 or drop us an email with pictures and we will tell you. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
What you get with us
- Colour agreed with you before work begins
- Trusted Arbo and Everbuild sealants
- 180+ five-star Google reviews
- An ARBOMaster approved applicator
Take a look at how sealant jobs are priced and what customers say.
Towns and villages near Dulwich
More services for Dulwich
Can I do it myself?
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 fails, we can still redo it.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
How we quote for new build mastic
You will get a clear quote before any work starts. It’s based on:
- How much old sealant there is and how hard it is to remove
- Which sealant suits the joint
- The number of rooms or windows
- When we can work, for business premises
What it costs depends on the amount of work, how much old material has to come out and access to the work. You’ll have a clear quote before any work starts, so you know where you stand.
Asking for a quote
Before you ask for a quote, have a think about:
- Any previous sealing or DIY work
- Any access issues, like height or stairs
- Where the job is, and your postcode
- A few photos by email, if you can
For a quote, call 0345 464 0079 or email us with the location and a short description of the problem. We’ll give you a clear price before any work starts.
What happens on the day
There’s no need to move everything out before we come, just the space around the work. Everything nearby is protected, and the job takes a few hours in a single home in most cases. In a London area like Dulwich, the main things to plan are parking and access: 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.
- Surfaces are cleaned of building dust and primed where needed.
- A sealant chosen for each area goes in and is tooled smooth.
- Finally, each room is checked and you are given the cure time.
Getting ready for the visit
- Clear the area around the work
- Keep children and pets away from the work area
- Tell us about any water getting in
Getting a quote
There’s no standard price list, as no two jobs are quite the same. Instead, we send you a clear quote for your job. To get started, ring 0345 464 0079 or drop us an email.
Read more
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Get a leaking seal dealt with straight away
- Wait for the cure time before using a resealed shower
- Use the extractor fan every time you shower
- Report sealant problems to your builder during the snagging period
Photograph failed sealant before it’s redone and keep the builder’s replies. It’s useful if you need to raise other issues later.
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.
New build mastic around Dulwich
Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent. London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Dulwich is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Dulwich is about 1 mile south-east of Herne Hill, in Greater London. Anywhere in SE22, our applicators can take on new build mastic. Dulwich is one of 764 places in Greater London we cover.
Postcode districts we cover here for new build mastic: SE22, SE21 and SE23. Local streets include Court Lane, Druce Road and Boxall Road. You’ll find Dulwich on the A2216, so it’s easy for us to get to. Other places close to Dulwich include Dulwich Village (1 mile north-west), West Dulwich (1 mile south), Herne Hill (1 mile north-west), Sydenham Hill (1 mile south-east) and Forest Hill (1 mile east). We also work in nearby towns such as London (4 miles north), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (7 miles north-west), St Pancras (6 miles north) and Shoreditch (6 miles north).
Landmarks near Dulwich
In Dulwich, that means homes and buildings near The Crown and Greyhound pub, Dulwich Park and Alleyn's School. For rail, the closest station is West Dulwich station, roughly 0.7 miles south-west. Other landmarks nearby include Dulwich Community Hospital (0.9 miles north) and Greenwich Castle (4 miles north-east). Not far away are Knight's Hill and Centre for Wildlife Gardening.
Do you need new build mastic in Dulwich?
Sealant applied onto damp surfaces does not bond well. On a busy site, joints are not always given time to dry first.
If you can see any of these, it’s time to have the joints looked at:
- Cracked sealant around new window and door frames
- Kitchen sealant that has pulled off the wall
- Gaps between new skirting and floors
- Sealant that never bonded to the surface
If you’ve bought a new home near West Dulwich station, the sealant around baths, showers and frames is worth checking in the first year or two.
Before booking anyone
- Is VAT in the price?
- Which colour the sealant will be
- What product goes in the joint
- How the joint is cleaned and prepared