Greater London · England
New-build mastic & snagging in Lee, Greater London
New build mastic for Lee and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Gaps behind new kitchen upstands
- Untidy sealant flagged on a snagging list
- Cracked caulk along new skirting
Why deal with it now?
The builder is generally the first port of call while the snagging or warranty period runs. If it keeps failing or is not dealt with, we can reseal it properly. In a flat in Lee, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part, and we will explain the quote if you ask.
Why choose Mr Mastic in Lee
- Sealant colour chosen to suit
- An ARBOMaster approved applicator
- Experience in homes, commercial sites and hotels
- 4.9 on Google from 180+ five-star reviews
Take a look at our cost guide or customer reviews.
New build mastic in Lee
Developers send us the plot schedule and we work through it. We seal bathrooms, kitchens, windows, doors and skirting so plots are ready to hand over with a sealant suited to each area. Typical jobs include internal frame sealant that has split and worktop and upstand sealant coming away, across bathrooms & en suites, plot handovers and kitchens.
London homes range from new-build flats to period conversions with new floors laid over old boards. Every joint between floor, skirting and threshold has to cope with some movement, in Lee as anywhere.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Lee (SE12, SE13, SE3)
- Wider area
- Greater London
- Cover
- One year on every job
- Quotes
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Your questions about new build mastic in Lee
Do you work for landlords with property near Lee station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
Is parking an issue for new build mastic in Lee?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly.
Will you just run a new bead over the existing one?
No. New silicone will not bond to old silicone, so it soon lifts and traps water. We cut the old bead out completely.
Where are you based?
Our base is in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so the joint is cleaned back first.
Will it make a mess?
Not at all. The area is protected while we work and cleaned up afterwards.
Is it normal for sealant to crack in a new home?
It’s common, and there are normally two reasons: the house moving as it dries, and sealant that never bonded properly. Cutting it out and resealing properly fixes both.
What information do you need?
Tell us what needs doing and where, plus pictures if you have them. We will ask anything else we need to know.
How it works
A visit follows a simple pattern: we look at the joints together, mask and protect the surrounding surfaces, do the work and clear up. Most jobs take a few hours in a single home. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We start by going through the snagging items or plot schedule with you.
- Every bit of the old builder’s sealant is cut out.
- Joints are vacuumed and cleaned of building dust.
- Primer goes on where the surface and product need it, then the new sealant.
- We tool every joint neatly and tell you when each area can be used.
Preparing for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Plan for the work area to be out of bounds to pets and children
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. Whenever you are ready, phone 0345 464 0079 or drop us an email.
Related advice
What the job involves on each surface
Skirting and floors
Where the floor meets a bath panel or kitchen plinth, the joint keeps mop water out. We seal them with a sealant suited to wet areas.
Show homes
We seal show-home bathrooms, kitchens and frames. Tell us when the home is open so we can plan around it.
For landlords and businesses
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can go on one quote.
What affects the cost of new build mastic
Every job gets its own quote. These are the things that affect it:
- Which sealant suits the joint
- Whether old sealant or filler has to be cut out
- The size of the job
- The number of rooms or windows
Doing several joints on one visit is normally more efficient than separate visits. You’ll get one clear quote for the whole job.
Asking for a quote
Photos help, but a description is a good start. Try to tell us:
- Any previous sealing or DIY work
- The type of property
- Roughly how big the job is
- A few photos by email, if you can
We do not publish a price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or send us an email.
Should I try it myself first?
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Other services in Lee
New build mastic in Lee: local notes
Many of London’s new homes are flats in bigger developments, where snagging may go through the developer or managing agent. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For new homes near Lee station, it’s worth checking the sealant early, while snags are still fresh.
Lee is about 2 miles south of Greenwich, in Greater London. From the centre of Lee to the outskirts, we cover new build mastic for every kind of property, from flats and houses to offices and hotels. Across Greater London, we cover 764 places, and Lee is one of them. There’s also a page for London, roughly 6 miles from Lee.
Work in SE12, SE13 and SE3 is quoted and booked the same way as anywhere else. If you need new build mastic at a property on Old Road, Manor Lane and Mallet Road or anywhere close by, we can help. We also cover the places around Lee: Hither Green (1 mile west), Horn Park (1 mile south-east), Lewisham (1 mile north-west), Ladywell (1 mile west) and Blackheath (1 mile north). Within a short drive, we also cover London (6 miles north-west), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (10 miles west), St Pancras (7 miles north-west) and Shoreditch (6 miles north-west).
Landmarks near Lee
In Lee, that means homes and buildings near Manor House Gardens, Trinity Church of England School and International Academy of Greenwich and the streets around them. Lee has its own railway station: Lee station. Well-known places in the area include Lewisham Shopping Centre (1.1 miles north-west) and Prefab Museum (1.3 miles south). Open spaces near Lee include Summer Hill and Birdbrook Road Nature Reserve.
What we are called out for in Lee
On many sites, sealant goes on in the final rush before handover. Joints are not always cleaned of dust or primed, so the bead never bonds properly.
The most common problems we see are:
- Untidy sealant flagged on a snagging list
- Kitchen sealant that has pulled off the wall
- Sealant work across a run of new homes
- Sealant applied over dusty or wet surfaces
Lee is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Comparing quotes
- Are they insured?
- Whether the sealant suits the joint
- What happens if the job turns out different
- When the joint can take water or movement