Greater London · England
Custom House New Build Mastic
Plot mastic for developers and snagging failed sealant in new homes for Custom House, backed by a one-year guarantee. Ask us for a quote.
- Gaps between new skirting and floors
- Cracked sealant around new window and door frames
- Messy sealant that spoils new finishes
How we handle new build mastic in Custom House
Some new-home owners let the house settle before resealing. That makes sense for small gaps that are just cosmetic, but a seal that is letting water through needs doing now. We work on kitchens, windows & doors and bathrooms & en suites, and common reasons people get in touch are shower seals failing in the first year or two and sealant applied over dusty or wet surfaces.
Shops, offices and commercial units across London have hard-wearing floors with movement joints that need resealing as they wear, and new homes need their plot mastic finished properly before handover, in Custom House and beyond.
Big or small, it’s backed by our 12-month guarantee in Custom House and across Greater London.
- Where
- Custom House (E16, E13)
- Wider area
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
DIY versus a professional finish
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
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.
Looking after it afterwards
Looking after new joints is easy, and it makes a real difference:
- Raise failed sealant with the developer while you’re covered
- Check bath and shower seals every few months as the house settles
- Use the extractor fan every time you shower
- Avoid running a DIY bead over the old one
Watch the joints as the house settles. Hairline gaps can open as timber and plaster dry, and they’re simple to reseal once movement has slowed.
A seal that splits early is often a sign of movement. Have it resealed, and the tray or bath checked, before it gets worse.
What happens on the day
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. For a job in Custom House, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- Each joint is checked for movement before any work starts.
- 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.
Preparing for the visit
- Keep pets and children clear of the area while we work
- Let us know if you’ve seen damp or leaks
- Let us know about earlier repairs to the joints
Getting a quote
Every job is quoted individually, so start by telling us what you need. Simply call 0345 464 0079 or email us and describe the job, and photos are welcome.
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Quotes for new build mastic in Custom House
The quote reflects the job in front of us. We take into account:
- Whether the work is at height
- Any mould that needs treating
- The amount of work
- Any working-time requirements on site
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we’ll go through it with you.
What we need to know
To help us quote quickly, please include:
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- A few photos by email, if you can
- Whether it’s a home or a business
Asking for a quote is easy: let us know the job and the location. Photos by email help us understand the job.
Leave it or put it right?
A tube of sealant from the DIY shop will not fix the cause: dust, no primer and old sealant left in the joint. Proper removal and preparation are what make it last. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
Why us?
- Trusted Arbo and Everbuild sealants
- 4.9 on Google from 180+ five-star reviews
- Old sealant always removed completely
- Fully insured
Take a look at what affects the cost and what customers say.
Landlords, agents and businesses in Custom House
Letting agents often deal with us directly. Tell us the address, the job and how access works and we’ll give you a quote.
If you manage several properties in or around Custom House, several properties can go on one quote. Just tell us the addresses and what each one needs, and pictures by email help.
New homes and floors in Custom House
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. Much of London’s new housing is flats in larger developments, where snagging may go through the developer or managing agent.
For new homes near Custom House station, it’s worth checking the sealant early, while snags are still fresh. As a London address, Custom House can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Custom House is about 1 mile south of Canning Town, in Greater London. We carry out new build mastic for householders, landlords and businesses in Custom House and nearby, as part of our work across Greater London. Our Greater London coverage runs to 764 places, Custom House among them.
Here we cover the E16 and E13 postcode area for new build mastic. You will find streets such as Tree Road, Ethel Road and Booth Road, all of which we cover. You’ll find Custom House on the A1020, which makes it straightforward to reach. Other places close to Custom House include West Silvertown (1 mile south-west), Silvertown (1 mile south), Canning Town (1 mile north), Royal Docks (1 mile east) and Limmo Peninsula (1 mile west). We also work in nearby towns such as London (5 miles west), City of Westminster (8 miles west), Marylebone (8 miles west), Kensington (10 miles west), St Pancras (6 miles west) and Shoreditch (5 miles west).
What’s near Custom House
Locally, jobs take us to homes and businesses close to Thames Barrier Park, The Royal Docks Community School and Royal Docks Academy and the streets around them. There’s a railway station in Custom House itself: Custom House station. Other landmarks nearby include Gallions Reach Shopping Park (2.2 miles east) and Charlton Athletic Museum (1.5 miles south). The countryside around Custom House includes Gilbert's Pit and Tower Hill.
What we cannot put right
We’d rather tell you now than do work that won’t last, so these are the limits:
- Disputes or warranty claims with your builder
- Movement caused by a poorly fitted tray or bath
- Settlement cracks that need a surveyor
If you’re not sure, just call 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
What we seal
- Show homes
- Skirting & floors
- Windows & doors
- Kitchens
- Bathrooms & en suites
- Plot handovers
Places near Custom House
Other services in Custom House
Custom House: your questions answered
Do you cover Custom House for new build mastic?
Yes, Custom House is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or send us an email and let us know what needs doing.
I let a flat near Custom House station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or send us an email with the address and a few details, and we will give you a fixed price before work begins.
How long should I leave it?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint.
Do I have to be there?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before resealing.
What information do you need?
Only a few details: the address or postcode, what’s wrong and any access issues. After that, simply call 0345 464 0079 or send us an email.
Are you fully insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Do you work through snagging lists?
Yes. Snagging lists are a common starting point for us. We agree the sealant items with you before work begins.