Greater London · England
New-build mastic & snagging in South Harrow, Greater London
Our applicators work in South Harrow on plot mastic for developers and snagging failed sealant in new homes. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Joints pulling apart as timber shrinks
- Smeared, uneven beads picked up at snagging
- Leaking shower tray seals in a new home
How we handle new build mastic in South Harrow
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 using the right product for each joint. We work on skirting & floors, kitchens and plot handovers, and common reasons people get in touch are sealant applied over dusty or wet surfaces and second-fix sealing on new plots.
Across London, commercial floors have movement joints that break down under heavy foot traffic, and new homes need their plot mastic finished properly before handover, in South Harrow and beyond.
Each job carries a 12-month guarantee, large or small.
- Where
- South Harrow (HA2, HA1, UB5)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What sealant work cannot fix
In fairness, some problems need a different trade:
- Deciding who is responsible under a builder’s warranty
- A tray or bath that is not properly supported, until it’s fixed
- Leaks from pipes, valves or wastes, which need a plumber
If you are not sure, just phone 0345 464 0079 or send us an email and we will give you a straight answer before you book.
Surfaces we seal
- Windows & doors
- Plot handovers
- Bathrooms & en suites
- Skirting & floors
- Kitchens
- Show homes
Common questions in South Harrow
Do you work for landlords with property near Northolt Park station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Is parking an issue for new build mastic in South Harrow?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Why has my new-build shower seal failed already?
New homes dry out and move in their first couple of years, and sealant is often applied quickly onto dusty surfaces. Either can make it fail early.
Can you quote for more than one area?
Yes. Just list everything you need and you’ll get one quote.
Can you reseal over the builder’s sealant?
No. Fresh silicone doesn’t stick to the old layer, so it soon lifts and traps water. We cut the old bead out completely.
Do you work in South Harrow?
Yes, we do. South Harrow is part of the area we cover.
Will the old sealant be removed?
Yes. Sealing over old sealant is the main reason resealing fails early, so we never do it.
Are you ARBOMaster approved?
Yes. We’re approved under the ARBOMaster scheme, the approved applicator scheme for Arbo sealants.
Towns and villages near South Harrow
What else we do in South Harrow
Quotes for new build mastic in South Harrow
Every job gets its own quote. These are the things that affect it:
- Working hours on commercial sites
- The old material and how stubborn it is
- The product the joint needs
- Access and height
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
Helping us quote
To make quoting easier, let us know:
- Access, such as stairs, a lift or height
- The type of property
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is.
What new build mastic looks like in South Harrow
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. Much of London’s new housing is flats in larger developments, where snags may need reporting through the developer or the managing agent.
If you’ve bought a new home near Northolt Park station, the sealant around baths, showers and frames is worth checking in the first year or two.
South Harrow is about 1 mile south of Harrow, in Greater London. Our applicators cover new build mastic for homes and businesses in South Harrow. South Harrow is one of 764 towns and villages in Greater London where we work. There’s also a page for London, roughly 12 miles from South Harrow.
Postcode districts we cover here for new build mastic: HA2, HA1 and UB5. Whether your property is on Park Lane, Grange Road and Dudley Road or a nearby road, we can help. We also cover Roxeth (1 mile north-east), Harrow (1 mile north), Harrow on the Hill (1 mile east), Rayners Lane (1 mile north-west) and Northolt (1 mile south-west). We also work in nearby towns such as London (12 miles east), City of Westminster (9 miles east), Marylebone (9 miles east), Kensington (8 miles south-east), St Pancras (10 miles east) and Shoreditch (12 miles east).
Around South Harrow
In South Harrow, that means homes and buildings near Orley Farm School, Northwick Park and St Dominic's Sixth Form College and the streets around them. The nearest railway station is Northolt Park station, roughly 0.5 miles south-west. Other landmarks nearby include St. George's Shopping Centre (1.3 miles north-east) and Kodak Museum (2 miles north). Green spaces nearby include Middle Lake and Northala Fields.
Keeping the joints in good condition
After the cure time, these simple habits help:
- Ventilate bathrooms well, especially in the first year
- Wipe joints with warm soapy water
- Wait for the cure time before using a resealed shower
- Put sealant faults on your snagging list early
Watch the joints as the house settles. Small gaps can appear as the house dries.
A failed seal in a new home lets water into joists, plasterboard and ceilings. Catching it early keeps the fix to the sealant and protects the rest of the house.
What the job involves on each surface
Kitchens
Worktop, upstand and sink joints in new kitchens often get a hurried bead. We take it out and reseal neatly, colour-matched where it shows.
Windows and doors
External mastic around new windows and doors is sometimes rushed or missed. It’s resealed with an exterior sealant suited to the frame and wall.
DIY versus a professional finish
A DIY attempt does not rule out a professional job. We remove it and do the joint properly.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
How the visit works
Once we’re on site, we compare the joints with what we discussed. If we find something unexpected, we talk it through with you first. After that, the work takes anything from a few hours to several days, depending on the number of plots. In South Harrow, 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, the list of joints is agreed from your snagging sheet or plot schedule.
- The failed sealant is removed completely.
- We clean out the dust and grit left from the build.
- 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.
Getting ready for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Tell us if parking is tricky
- Mention if the joints have been sealed before
How to get a quote
For a quote, phone 0345 464 0079 or send us an email with the location and a short description of the problem. We’ll give you a clear price before any work starts.
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When to call us in South Harrow
Sealant applied onto damp surfaces does not bond well. Site programmes don’t always leave time for joints to dry first.
People usually contact us after spotting something like this:
- New-build shower sealant that has already split
- Kitchen sealant that has pulled off the wall
- Cracked sealant around new window and door frames
- Sealant that never bonded to the surface
South Harrow is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Before you book anyone
- Whether they’re fully insured
- What product goes in the joint
- When the joint can take water or movement
- Who does the work, and how experienced they are