Greater London · England
Haverstock Sand Mastic
Sand mastic across Haverstock and nearby, with old sealant always removed completely.
- Mastic that needs renewing before redecorating
- Old cement repairs round a window that have failed
- Gaps round a timber door in stone or brick
When to call us in Haverstock
Most of it is simply age. Sand mastic is a maintenance item like any pointing, depending on exposure and upkeep.
Common reasons people contact us include:
- Draughty sash windows at the surround
- Patchy fillers round a sash window
- Gaps between timber frames and stone or brick
- Failed mastic on an exposed elevation
If you let a flat or house near South Hampstead station, cracked sand mastic around sash windows lets in the draughts tenants complain about.
What to look for in a quote
- Whether they seal over old material or remove it
- Which sealant they’ll use, and why
- How long to leave it before use
- Whether VAT is included
About our sand mastic in Haverstock
Across Haverstock, we renew sand mastic around sash and case windows. Each joint is raked out, prepared and pointed by hand, finished to suit the masonry. Common call-outs are for gaps round a timber door in stone or brick and mastic that needs renewing before redecorating, on period & listed homes, tenement windows and brick reveals.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first.
Your job is guaranteed for a year, as with all our work.
- Where
- Haverstock (NW3, NW5, NW1)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
Also near Haverstock
Other services in Haverstock
Questions from Haverstock
Can you help a landlord with a rental near South Hampstead station?
Yes, we work for letting agents and landlords. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Can parking be tricky for a visit in Haverstock?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Will you leave a mess?
We keep the work tidy. Nearby surfaces are protected, and the area is left clean when we finish.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
How long does sand mastic take?
It depends on the size of the job, but as a guide it takes a few hours per window, depending on the condition of the joints. We will tell you when we quote.
Can sand mastic be painted?
Traditional guidance is not to paint over sand mastic. Ask us before you decorate around it and we’ll talk you through it.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done and we’ll quote it together.
How long does sand mastic take to go off?
Not right away. It skins first and hardens fully later, and we’ll tell you what to expect.
Why it’s worth doing now in Haverstock
Filling over old, loose mastic doesn’t last. Raking out and preparing the joint gives it a sound base so the new work lasts. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are not sure whether it needs doing, call 0345 464 0079 or send us an email for an honest opinion and a quote.
Why us?
- 4.9 on Google from 180+ five-star reviews
- Fully insured
- We never seal over old sealant
- Approved under the ARBOMaster scheme
Read our cost guide or customer reviews.
What happens on the day
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours per window, depending on the condition of the joints, and the area is left clean. In Haverstock, 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, we look at the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The finish is dressed so it sits neatly against the stone or brick.
Preparing for the visit
- For business premises, tell us about site rules or sign-in
- Where the joints are inside, avoid wetting them before we arrive
- Clear the area around the work
How to get a quote
Call for a quick quote, or email us if that is easier. Tell us about the joints that need doing and we’ll explain what’s involved before giving you a price.
Related advice
What sand mastic looks like in Haverstock
With historic houses such as Keats House (about 0.8 miles north) nearby, there’s older building stock in the area around Haverstock as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book.
In the older streets around Church of St Mary the Virgin, the joint between an old wall and a newer frame is usually the first place rain gets in. Haverstock is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Haverstock is about 1 mile south-east of Hampstead, in Greater London. Whether you are in the middle of Haverstock or further out, we cover sand mastic for every kind of property. Our Greater London coverage runs to 764 places, Haverstock among them.
All of NW3, NW5 and NW1 is within our area for sand mastic. That includes homes and businesses on Eton Road, Lawn Road and Ornan Road. Neighbouring places we cover for sand mastic include Belsize Park (1 mile north), Primrose Hill (1 mile south), South Hampstead (1 mile west), Swiss Cottage (1 mile west) and Chalk Farm (1 mile east). Within a short drive, we also cover London (4 miles south-east), Kensington (4 miles south-west), Shoreditch (4 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles east) and Whitechapel (4 miles south-east).
Local landmarks in Haverstock
We work in homes and buildings around Cecil Sharp House, Primrose Hill and St. Mary's Town and Country School. Nearby too are St Paul's Church of England Primary School (under half a mile south) and The Washington pub (less than half a mile north). For rail, the closest station is South Hampstead station, roughly 0.7 miles west of the centre. Well-known places in the area include Wellington Hospital (0.9 miles south-west) and Isokon Gallery (0.5 miles north). The countryside around Haverstock includes Adelaide Nature Reserve and Primrose Hill.
Landlord and commercial work in Haverstock
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
We also work for property managers and facilities teams. We can quote a run of properties together.
How we quote for sand mastic
Call for a quick quote. What matters most is:
- The product the joint needs
- Any working-time requirements on site
- The size of the job
- How many areas need sealing
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What to tell us for a quote
Photos help, but a description is a good start. Try to tell us:
- What’s wrong with the joints now
- Where the job is, and your postcode
- Access, such as stairs, a lift or height
- Whether it’s a home or a business
We don’t publish a price list. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or email us.
Looking after it afterwards
A little care helps the new joints last. Our advice:
- Look over the window mastic once a year
- Ask us before painting near the mastic
- Find out about consent before window work on a listed home
- Clear gutters so water doesn’t pour onto the windows
Leave the new mastic unpainted, as traditional guidance advises. Ask us before any decorating around it.
Small cracks are a sign the mastic is ageing. It’s easier to renew it before it drops out.