Greater London · England
New Build Mastic in Sydenham Hill
Our applicators work in Sydenham Hill on plot mastic for developers and snagging failed sealant in new homes. Old sealant removed completely, joints prepared properly.
- Joints pulling apart as timber shrinks
- Gaps between new skirting and floors
- Sealant applied over dusty or wet surfaces
How to look after the new joints
No joint lasts for ever, but care makes a real difference. Our tips:
- Wait for the cure time before using a resealed shower
- Wipe joints with warm soapy water
- Ventilate bathrooms well, especially in the first year
- Check bath and shower seals every few months as the house settles
Avoid standing on the rim of the bath or the edge of the tray while the sealant cures. If a bath or tray moves when you stand in it, get it looked at.
A seal that splits early is often a sign of movement. Getting it resealed properly, and any movement checked, stops it recurring.
New build mastic for homes and businesses in Sydenham Hill
Our new-build work comes in two parts: plot mastic for developers, and putting right failed sealant for people who’ve bought a new home. Both get the same care over preparation since hurried prep is behind a lot of new-build failures. We’re often asked to deal with sealant work across a run of new homes and shower seals failing in the first year or two, on bathrooms & en suites, kitchens and show homes.
From brand-new flats to converted terraces with new flooring, London has every kind of floor. Every joint between floor, skirting and threshold has to cope with some movement.
Your job is guaranteed for a year, as with all our work.
- Location
- Sydenham Hill (SE26, SE23, SE21)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
How we quote for new build mastic
Your quote is based on your job. We take into account:
- The product the joint needs
- Access and height
- The number and length of the joints
- Whether there’s mould to deal with
The cost reflects the work involved, not guesswork. That’s why we ask a few questions first.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Pictures of the joints, sent by email
- Any access issues, like height or stairs
- What’s wrong with the joints now
- If it’s domestic, commercial or a hotel
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or drop us an email.
Why it’s worth doing now in Sydenham Hill
Resealing everything on a snagging list in one visit is usually simpler than chasing joints one at a time. You get one visit and one clear quote for the lot. In a flat in Sydenham Hill, 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.
Leaving a failed joint generally makes the job bigger, not smaller, because water and mould keep working on it. If you are unsure, phone 0345 464 0079 or send us an email for an honest opinion and a quote.
Why book with us
- ARBOMaster approved applicator
- Any old sealant cut out fully, not covered over
- Homes, businesses and hotels
- 4.9 on Google from 180+ five-star reviews
Take a look at what affects the cost and our reviews.
Common questions in Sydenham Hill
Can you do new build mastic in Sydenham Hill?
Yes, Sydenham Hill 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 let us know what needs doing, and we will send you a clear quote.
Can parking be tricky for a visit in Sydenham Hill?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We’ll tell you what we are using and why.
How long does the job take?
Most jobs take 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?
Yes, though it’s best to check with your landlord first. Landlords are often happy for the work to be arranged.
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. The old sealant always comes out first.
Do the sealants smell?
Sometimes, a little. Any smell clears as the sealant cures.
Why does sealant fail so quickly in new builds?
Lots of new homes see sealant crack early, because the house is drying and settling. Rushed application on dusty surfaces makes it worse.
What new build mastic looks like in Sydenham Hill
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. Many of London’s new homes are flats in bigger developments, where snags may need reporting through the developer or the managing agent.
If you’ve bought a new home near Sydenham Hill station, the sealant around baths, showers and frames is worth checking in the first year or two. As a London address, Sydenham Hill can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Sydenham Hill is about 1 mile east of West Norwood, in Greater London. From the centre of Sydenham Hill to the outskirts, we cover new build mastic for every kind of property. Our Greater London coverage runs to 764 places, and Sydenham Hill is one of them.
Jobs for new build mastic in SE26, SE23 and SE21 works the same way as everywhere else we cover. Local streets include Grange Lane, Dallas Road and Lyall Avenue, all of which we cover. Close by, we work in West Dulwich (1 mile west), Sydenham (1 mile south-east), Crystal Palace (1 mile south), Dulwich (1 mile north-west) and Gipsy Hill (1 mile south-west). Further out, we also cover London (5 miles north), City of Westminster (7 miles north-west), Marylebone (7 miles north-west), Kensington (7 miles north-west), St Pancras (7 miles north) and Shoreditch (6 miles north).
Landmarks near Sydenham Hill
In Sydenham Hill, that means homes and buildings near Long Meadow, The Wood House and Sydenham School and the streets around them. The closest station to Sydenham Hill is Sydenham Hill station, about 0.5 miles west of the centre. A little further out are Horniman Museum and Gardens (0.6 miles north-east) and Lewisham Shopping Centre (3.2 miles north-east). The countryside around Sydenham Hill includes Knight's Hill and Dulwich Upper Wood.
What the job involves on each surface
Show homes
We can refresh show-home sealant that has discoloured or been knocked. The old bead comes out and a clean new one goes in.
Windows and doors
On new builds, external frame sealant can be patchy. We reseal it with a weatherproof, flexible sealant.
When something else is needed
Sealant isn’t the answer to every problem, and we will tell you before we start. It will not solve:
- Structural cracks in walls or ceilings
- Cracked trays, tiles or worktops
- Movement caused by a poorly fitted tray or bath
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before booking.
Surfaces we seal
- Bathrooms & en suites
- Plot handovers
- Windows & doors
- Show homes
- Kitchens
- Skirting & floors
Work for landlords, hotels and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can be quoted together.
If you manage several properties in or around Sydenham Hill, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs, and photos by email help.
How the visit works
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the work takes a few hours for most snagging lists, longer for a run of plots for a typical job. In Sydenham Hill, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by going through the snagging items or plot schedule with you.
- The failed sealant is removed completely down to clean surfaces.
- 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.
Preparing for the visit
- Mention any tricky access
- Tell us if parking is tricky
- On commercial sites, let us know about site rules
Get a quote
Getting a quote is simple: tell us what needs doing and where, and roughly how big it is. A few photos by email make the job easier to understand, and we’ll take it from there.