South East England and London
New Build Mastic in City of London
Covering 1 places across City of London for new build mastic, done properly, quoted clearly before any work starts and a one-year guarantee.
Where we work in City of London
Plot mastic for developers and snagging failed sealant in new homes. Pick your town below to see the details for your area, or call or email us for a quick quote.
Largest places
More services in City of London
- External & façade joints
- Gutter, fascia & soffit sealing
- Sand mastic for sash & case windows
- Glazing & conservatory sealant
- Commercial & hotel sealant
- Bathroom & kitchen resealing
- Window & door mastic
- Fire-rated sealant
- Floor & skirting joints
- Regrouting
- Remedial sealant & repairs
Postcode areas we cover
About new build mastic in City of London
Some new-home owners let the house settle before resealing. For small cosmetic gaps, that’s reasonable, but a seal that’s letting water through needs doing now. Typical jobs include gaps between new skirting and floors and untidy sealant flagged on a snagging list, on show homes, bathrooms & en suites and skirting & floors.
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes a few hours for most snagging lists, longer for a run of plots, depending on the size of the job.
- First, the list of joints is agreed from your snagging sheet or plot schedule.
- Every bit of the old builder’s sealant is cut out, with no layer left behind.
- Joints are vacuumed and cleaned of building dust.
- We prime where needed and apply a sealant suited to each joint.
- We tool every joint neatly and tell you when each area can be used.
Pricing in City of London
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
What you get with us
- 180+ five-star Google reviews
- Colour picked to suit the job
- Experience in homes, commercial sites and hotels
- Full insurance on every job
Get a quote
There’s no standard price list. Instead, we give you a clear quote for your job. To get started, call 0345 464 0079 or drop us an email.
Local landmarks in City of London
Around City of London, our work takes us to homes and buildings near Fashion Retail Academy, Prior Weston Primary School and Children's Centre and Barts Health Archives, among other places. Nearby too are Golden Fleece pub (under half a mile south), St Alphage Garden (within half a mile north), Central Foundation Boys' School (0.8 miles north) and St Mary-at-Hill (0.5 miles south-east). There’s a railway station in City of London itself: London Cannon Street station. Well-known places in the area include Gabriel's Wharf (0.8 miles south-west) and London Mithraeum (less than half a mile south). For a walk, there’s St. James's Park Lake and Barnsbury Wood.
- Local churches include St Olave Old Jewry (under half a mile east)
New build mastic across City of London: local notes
Our new build mastic work across City of London covers developers, householders and businesses, from City of London to the quieter places in between. The common thread is movement: every joint has to allow for it.
Most of the South East has hard water, so limescale builds up on sealant, grout and fittings. For any job in City of London, joints are cleaned back properly before anything new goes in.
City of London: As a London address, City of London can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. For new homes near London Cannon Street station, it’s worth checking the sealant early, while snags are still fresh.
How to look after the new joints
Looking after new joints is easy, and it makes a real difference:
- Photograph failed sealant before it’s redone
- Do not wait for the house to settle if water is getting through
- Raise failed sealant with the developer while you are covered
- Look at the sealant regularly in the first couple of years
Watch the joints as the house settles. Small gaps can appear as the house dries, and they’re simple to reseal once movement has slowed.
A failed seal in a new home lets water into joists, plasterboard and ceilings. Catching it early keeps the fix to the sealant and the new finishes intact.
Can I do it myself?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Signs you need new build mastic
Baths and trays settle under load once the home is lived in. A bath sealed empty drops slightly when filled, straining the joint and the sealant may split.
The problems people generally mention when they call include:
- Leaking shower tray seals in a new home
- Worktop and upstand sealant coming away
- Frame joints opening as the plaster dries
- Untidy sealant flagged on a snagging list
Different surfaces, different methods
Skirting and floors
New homes often develop a gap between skirting and floor. A flexible sealant closes it without cracking like caulk.
Plot handovers
Good preparation at handover saves snagging later. Dust from the build is removed first and primer used where needed.
When something else is needed
New sealant cannot fix everything, and we’d rather say so up front. It will not solve:
- Deciding who is responsible under a builder’s warranty
- Structural cracks in walls or ceilings
- Broken tiles or a split tray
Common questions in City of London
Do you take on second-fix sealing for builders?
Yes. Second-fix sealing in bathrooms, kitchens, frames and floors is part of what we do. Good preparation keeps snagging to a minimum.
Can landlords and businesses book you?
Yes, we do. Domestic, commercial and hotel work are all part of what we do.
Can you work from my snagging list?
Yes. Send us the sealant items on the list, with photos if you can and we’ll give you a quote. We will flag anything that needs another trade.
Where is Mr Mastic based?
We are a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
What sealant do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Do you use white or clear sealant?
The colour is chosen to suit the tiles, worktop or frame. Tell us what you’d like when you get a quote.
Are you fully insured?
Yes. We are fully insured, with over 20 years’ experience in sealant work.