Surrey · England
New Build Mastic in Downside
New build mastic across Downside and nearby, with old sealant always removed completely and a 12-month guarantee.
- Internal frame sealant that has split
- Shower seals failing in the first year or two
- Kitchen sealant that has pulled off the wall
How we handle new build mastic in Downside
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. If you have sealant applied over dusty or wet surfaces and cracks appearing as a new home settles, we can help, whatever the surface.
Older homes in small places like Downside often have timber floors that move with the seasons, so skirting and threshold joints need a flexible sealant rather than a rigid filler.
There’s a 12-month guarantee on every job, large or small.
- Where
- Downside (KT11)
- Region
- Surrey
- Guarantee
- A year, on every job
- Quote
- A clear price before we start
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How we quote for new build mastic
Some jobs are bigger than they look, and some smaller. The main factors:
- The size of the job
- The old material and how stubborn it is
- Working hours on commercial sites
- Whether there’s mould to deal with
What it costs depends on the amount of work, how much old material has to come out and access to the work. You will have a clear quote before any work starts.
What we need to know
What to tell us when you ask for a quote:
- Where the job is, and your postcode
- Whether it’s a home or a business
- The rough size of the job
- Whether it has been sealed before
Want a quote for new build mastic? Please ring 0345 464 0079 or send us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Common problems we fix in Downside
Fresh sealant can be knocked or cut by trades finishing off. If it’s disturbed before curing, the joint can be left weak.
The most common problems we see are:
- Gaps behind new kitchen upstands
- Sealant work across a run of new homes
- Shower seals failing in the first year or two
- Internal frame sealant that has split
In and around Downside, as anywhere, good new build mastic starts with a clean, dry, properly prepared joint.
Comparing quotes
- Is the old sealant removed completely?
- What insurance they hold
- How the surfaces are prepared before sealing
- Who turns up on the day
Places near Downside
What else we do in Downside
Why it’s worth doing now in Downside
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. Around Downside, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote.
Why Downside clients choose us
- Trusted Arbo and Everbuild sealants
- We are fully insured
- An ARBOMaster approved applicator
- Over 20 years’ experience
Take a look at our cost guide and what customers say.
New build mastic in Downside: local notes
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For new homes near Cobham & Stoke Dabernon station, it’s worth checking the sealant early, while snags are still fresh.
Downside is about 4 miles west of Leatherhead, in Surrey. Jobs in Downside get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Our area takes in 395 places across Surrey, from the larger towns to small villages. You can also see our page for Crawley, roughly 17 miles from Downside.
We work across the KT11 postcode area for new build mastic. That includes homes and businesses on Downside Common, Downsview Close and Deacon Close and the roads around them. Close by, we work in Hatchford (1 mile west), Martyr's Green (1 mile south-west), Hatchford End (2 miles west), Whiteley Village (3 miles north) and Wisley (3 miles west). Further out, we also cover Guildford (8 miles south-west), Woking (7 miles west), Camberley (14 miles west), Epsom (6 miles east), Horley (14 miles south-east) and Redhill (12 miles south-east).
Near you in Downside
Around Downside, our work takes us to homes and buildings near The Plough Public House and Parkside School and the streets around them. For rail, the closest station is Cobham & Stoke Dabernon station, about 1 mile north-east. A little further out are Epsom Cottage Hospital (5.1 miles north-east) and Send and Ripley History Society Museum (3.8 miles west). Green spaces nearby include Jubilee Wood and Boldermere Lake.
Aftercare tips
After the cure time, these simple habits help:
- Check bath and shower seals every few months as the house settles
- Resist patching a failed seal with a tube from the DIY shop
- Record problems with dated photos
- Wait for the cure time before using a resealed shower
Watch the joints as the house settles. Small gaps can appear as the house dries and can be resealed later.
Don’t let the snagging period run out with sealant problems unreported. Once it ends, the repair may be down to you so report it promptly.
When it is not the sealant
We’d rather tell you now than do work that won’t last, so here’s what sealant can’t put right:
- Your warranty claim itself, which is between you and the builder
- Structural cracks in walls or ceilings
- Cracked trays, tiles or worktops
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we’ll tell you honestly.
Surfaces we seal
- Skirting & floors
- Bathrooms & en suites
- Plot handovers
- Windows & doors
- Show homes
- Kitchens
How the visit works
Good joint work is mostly preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours in a single home. In a small place like Downside, access is usually the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by going through the snagging items or plot schedule with you.
- The failed sealant is removed completely, 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.
Getting ready for the visit
- Clear items away from the joints we’re working on
- Let us know if you’ve seen damp or leaks
- Let us know about stairs, lifts or work at height
Ask for a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email pictures if that is easy.
Read more
Landlords, agents and businesses in Downside
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can be quoted together.
FAQs for Downside
Do you cover smaller places like Downside?
Yes, Downside is covered. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can you do new build mastic in Downside?
Yes, Downside is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job.
Do you do commercial work?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
How much does new build mastic cost in Downside?
We don’t publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Do you work for developers?
Yes. We take on second-fix sealant work across new plots. Good preparation keeps snagging to a minimum.
Can you reseal over the builder’s sealant?
No. Over-sealing traps mould and water and soon fails. We remove every bit of the old bead before resealing.
Where is Mr Mastic based?
We’re based in Crawley, and we work across South East England, London and Scotland.
Can you quote for more than one area?
Of course. Doing several areas at once is normally more efficient.