Greater London · England
New Build Mastic in Deptford
Plot mastic for developers and snagging failed sealant in new homes for homeowners, landlords and businesses in Deptford. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Beads laid onto grit and dust from the build
- Cracked sealant around new window and door frames
- Smeared, uneven beads picked up at snagging
Work for landlords, hotels and businesses
We regularly work with letting and managing agents. Tell us the address, the job and how access works.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
New build mastic in Deptford
Building dust is behind a lot of failed new-build sealant. We clean every joint thoroughly and prime where the surface and product need it, so the new bead bonds properly rather than sitting on a layer of grit. Common call-outs are for cracks appearing as a new home settles and skirting joints opening in the first winter, on bathrooms & en suites, show homes and windows & doors.
London homes range from new-build flats to period conversions with new floors laid over old boards. Wherever a floor meets a wall, a skirting or a threshold, the joint has to allow for movement.
You get a one-year guarantee, the same in Deptford as everywhere else we work.
- Place
- Deptford (SE8, SE10, SE14)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Deptford
Other services in Deptford
What sealant work cannot fix
We will not take on work that will not last, so these are the limits:
- Structural cracks in walls or ceilings
- Movement caused by a poorly fitted tray or bath
- Cracked trays, tiles or worktops
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think.
What we seal
- Windows & doors
- Skirting & floors
- Bathrooms & en suites
- Plot handovers
- Show homes
- Kitchens
How the job changes by surface
Bathrooms and en suites
En suite seals are easy to miss on a snagging list until they leak. Resealing properly keeps water where it belongs.
Windows and doors
Internal joints between frames and plaster often crack as a new house dries. We cut out the cracked bead and reseal with a flexible sealant.
The process
Most of a good job is in the preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours for most snagging lists, longer for a run of plots. In Deptford, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- First we work through your snagging list or plot schedule with you.
- We cut out every bit of the failed or messy sealant.
- Each joint is cleaned of dust and grit, then primed if required.
- A sealant chosen for each area goes in and is tooled smooth.
- Finally, each room is checked and you’re given the cure time.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- On commercial sites, let us know about site rules
- Let us know if you’ve seen damp or leaks
Get a quote
There’s no standard price list. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or send us an email.
Related advice
Why it’s worth doing now in Deptford
DIY kits do not solve the main problems with new-build sealant: dust, no primer and old sealant left in the joint. Cutting out, cleaning and priming are what make the difference. In a flat in Deptford, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
Why us?
- Neat joints and a tidy finish
- Colour picked to suit the job
- ARBOMaster approved applicator
- White, clear, grey or coloured to suit, where the product allows
Take a look at how sealant jobs are priced and what customers say.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
Deptford questions
Can parking be tricky for a visit in Deptford?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Can you do new build mastic in Deptford?
Yes, Deptford is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and let us know what needs doing.
Can I add another job to the visit?
Yes. More than one area can go on one quote.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Deptford.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status.
How long does the job take?
That depends on how much there is to do, but most jobs take anything from a few hours to several days, depending on the number of plots. We will give you a better idea when we quote.
Is it worth trying it myself?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Can landlords and businesses book you?
Yes. As well as householders, we work for landlords, agents, businesses and hotels.
What new build mastic looks like in Deptford
Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Deptford is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. For new homes near Deptford station, it’s worth checking the sealant early, while snags are still fresh.
Deptford is about 3 miles south-east of Whitechapel, in Greater London. Deptford gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across Greater London, we cover 764 places, and Deptford is one of them.
Work in SE8, SE10 and SE14 is quoted and booked the same way as anywhere else. We cover properties on Mill Lane, Dixon Road and Clare Road. Being close to the A2209, Deptford is easy for our applicators to reach for new build mastic. Other places close to Deptford include New Cross (1 mile south-west), St Johns (1 mile south), Millwall (1 mile north), Isle of Dogs (1 mile north-east) and North Greenwich (1 mile north-east). Within a short drive, we also cover London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north-west).
Local landmarks in Deptford
In Deptford, that means homes and buildings near Addey and Stanhope School, Sue Godfrey Nature Park and Deptford Arms. Deptford has its own railway station: Deptford station. Nearby you’ll also find Greenwich Castle (1.1 miles east) and Lewisham Shopping Centre (1.3 miles south-east). Not far away are Sue Godfrey Nature Park and Tower Hill.
How we quote for new build mastic
You will get a clear quote before work begins. It’s based on:
- How many rooms, windows or areas are involved
- The product the joint needs
- Access and height
- Mould in or behind the old joints
Some things make a job bigger or smaller: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
What we need to know
Before you ask for a quote, have a think about:
- Whether it’s a home or a business
- The problem you’ve noticed
- The address or postcode of the job
- Whether it has been sealed before
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.