Greater London · England
Childs Hill Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Childs Hill, backed by a one-year guarantee. Ask us for a quote.
- Draughts and rain around sash boxes
- Old cement repairs round a window that have failed
- Old sand mastic that has cracked, crumbled or fallen out
The process
When we arrive, we start by going over the job with you, so you know exactly what we are doing. We protect the surfaces around the joints before any work starts. The work generally takes anything from a few hours to a full day, depending on how many windows. In a London area like Childs Hill, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Getting ready for the visit
- Tell us about any previous sealing or DIY attempts
- For indoor joints, keep the area dry beforehand if you can
- Keep pets and children clear of the area while we work
Get a quote
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we will talk you through the work.
Read more
About our sand mastic in Childs Hill
Fresh sand mastic forms a skin quite soon, but it takes longer to harden fully. Traditionally, sand mastic is left unpainted, so ask us before you decorate. If you have gaps between timber frames and stone or brick and cement or filler used on old window joints that has cracked, we can help, on period & listed homes, tenement windows and timber door frames alike.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
All of our work is guaranteed for twelve months, in Childs Hill and everywhere else we cover.
- Location
- Childs Hill (NW2, NW3, NW11)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
How to look after the new joints
To keep the joints looking good and working properly:
- Keep modern sealant off the mastic
- Take care around the mastic when scraping paint
- Leave the new mastic unpainted
- Have rotten timber repaired before new mastic goes in
Make sure water drains away from the window surround. Constant wetting wears the mastic faster.
It’s best to renew mastic before painting the windows. Painting over failed mastic hides the problem for a while.
Childs Hill questions
Is parking an issue for sand mastic in Childs Hill?
Parking in Childs Hill, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
I let a flat near Cricklewood station. Can you help?
Yes. We work for landlords and letting agents as well as householders. Just call 0345 464 0079 or email us with the address and what needs doing, and we will give you a clear price.
Which products do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We explain the product when we quote.
Can sand mastic be painted?
It’s traditionally left unpainted, as guidance on traditional windows advises. Talk to us before any painting near it.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area to suit the site.
Do you have insurance?
Yes. We’re fully insured.
What’s sand mastic made of?
Sand mastic is a traditional material for pointing round windows and doors. It’s made with sand and a linseed-oil-based binder.
Surface by surface
Period and listed homes
Materials matter on listed and conservation-area homes. Sand mastic is often the preferred finish.
Sash and case windows
On a sash window, the mastic joint shows on the outside so we finish it carefully.
Childs Hill homes and the weather
With historic houses such as Heath House (about 0.7 miles east) nearby, there’s older building stock in the area around Childs Hill as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Rented homes near Cricklewood station change hands often, and any sash windows need sound mastic to keep draughts and rain out. If you look after a building such as All Saints' CofE Primary School NW2, its window and door frames need their mastic kept sound, just like a home’s.
Childs Hill is about 1 mile north-west of West Hampstead, in Greater London. If you need sand mastic in Childs Hill, please ring 0345 464 0079 or drop us an email for a quick quote. We cover Greater London from our Crawley base. We cover 764 towns and villages across Greater London, from the larger towns to small villages. London is on our list too, about 6 miles from Childs Hill.
All of NW2, NW3 and NW11 is covered for sand mastic, from the main roads to the quietest streets. Whether your property is on Nant Road, Ridge Road and Garth Road or a nearby road, our applicators can take on the job. If you’re just outside Childs Hill, we cover Fortune Green (1 mile south), West Hampstead (1 mile south-east), Golders Green (1 mile north), North End (1 mile north-east) and Vale of Health (1 mile east). We also work in nearby towns such as London (6 miles south-east), City of Westminster (4 miles south-east), Marylebone (4 miles south-east), Kensington (4 miles south), St Pancras (4 miles south-east) and Shoreditch (6 miles south-east).
Around Childs Hill
In Childs Hill, that means homes and buildings near St Vedasts School For Boys, Hampstead School and The Old Bull and Bush pub. The closest station to Childs Hill is Cricklewood station, roughly 0.7 miles south-west. A little further out are O2 Centre (1.2 miles south-east) and New End Hospital (0.9 miles east). Green spaces nearby include Parliament Hill and Westbere Copse.
Why act early in Childs Hill
New sash windows are a major, costly change and on a listed home, consent may be needed. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
Doing several joints on one visit is normally more efficient than separate visits. You will get one clear quote for the whole job.
Why book with us
- Over 20 years’ experience
- Domestic, commercial and hotel work
- Sanitary silicone with an anti-fungal additive in wet areas
- Trusted Arbo and Everbuild sealants
Take a look at what affects the cost or customer reviews.
What affects the cost of sand mastic
You will get a clear quote before any work starts. It takes into account:
- How many areas need sealing
- The product the joint needs
- Mould in or behind the old joints
- The number and length of the joints
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we will explain what it covers.
What to tell us for a quote
You do not need to know the technical terms. Just tell us:
- Photos by email, if that’s easy
- Access, such as stairs, a lift or height
- Whether it’s a home or a business
- How many joints, rooms or windows are involved
Need a quote? Please ring 0345 464 0079 or send us an email with a few details. We’ll explain what we’d do and give you a clear price before any work starts.
When to call us in Childs Hill
Most of it is simply age. Even well-laid mastic needs renewing in time, depending on exposure and upkeep.
Most people get in touch after spotting something like this:
- Gaps where the frame meets the masonry
- Old cement repairs round a window that have failed
- Mastic worn away on windows facing the weather
- Tired mastic found when preparing windows for paint
For an older house near a landmark such as All Saints, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Before booking anyone
- What the quote includes, VAT included or not
- Are they insured?
- What the cure time is
- What product goes in the joint
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can go on one quote.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.