Greater London · England
Sand mastic for sash & case windows in Coldharbour, Greater London
Problem with your window and door surrounds in Coldharbour? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Gaps round a timber door in stone or brick
- Mastic worn away on windows facing the weather
- A silicone bead on a sash window that spoils the look
How we handle sand mastic in Coldharbour
Our applicators renew the sand mastic around sash and case windows and doors set in stone or brick. Out comes the old, loose mastic, the joint is prepared and new mastic is shaped by hand. If you have gaps round a timber door in stone or brick and draughty sash windows at the surround, we can help.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, letting in draughts and water.
You are covered for a year from the day we finish. If anything isn’t right with it, call 0345 464 0079 or drop us an email.
- Place
- Coldharbour (E14, SE10, E22)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Quotes for sand mastic in Coldharbour
Call for a quick quote. The main things that affect it are:
- When we can work, for business premises
- Whether the work is at height
- The number and length of the joints
- Whether old sealant or filler has to be cut out
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed. Ask us for a quote and we’ll explain what it covers.
Asking for a quote
There’s no need for technical detail. Just tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- The type of property
- Any previous sealing or DIY work
- Where the job is, and your postcode
Getting a quote is simple: let us know what needs doing and where and its rough size. Photos by email help us understand the job.
How to look after the new joints
A little care helps the new joints last. Our advice:
- Have rotten timber repaired before new mastic goes in
- Ask us before painting near the mastic
- Plan mastic work ahead of painting
- Inspect the joints round the windows every year or so
Keep gutters and sills clear so water runs away from the surround. Constant wetting wears the mastic faster.
Renewing mastic before redecorating saves doing it twice. Painting over failed mastic hides the problem for a while.
For landlords and businesses
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 that we can handle for you.
We also work for property managers and facilities teams. Several sites can go on one quote, and we’re fully insured.
Why it’s worth doing now in Coldharbour
Not every filler suits an old window surround. Sand mastic is the like-for-like choice and that can be important for listed homes. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why us?
- Quality sealants from Arbo and Everbuild
- ARBOMaster approved applicator
- Over 20 years’ experience
- Homes, businesses and hotels
Read how sealant jobs are priced or our reviews.
What we are called out for in Coldharbour
Water gets into small cracks in the mastic and pushes it out. Windows facing the weather tend to go first.
People generally contact us after spotting one of these:
- Gaps round a timber door in stone or brick
- Gaps where the frame meets the masonry
- Draughty sash windows at the surround
- Modern sealant on a period surround
As a London address, Coldharbour can be tricky for parking: let us know about parking bays, permits or a driveway.
What your quote should include
- How the colour is chosen
- Whether they seal over old material or remove it
- What happens if the job turns out different
- Whether they’re fully insured
Also near Coldharbour
Also in Coldharbour
How the visit works
We bring everything the job needs with us. Once we’ve agreed what’s being done, we protect the area and start. Most jobs take a few hours for a single window, longer for several. In Coldharbour, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
How to prepare
- Tell us about any water getting in
- Mention any sign-in or site rules at work premises
- Clear items away from the joints we’re working on
Getting a quote
For a quote, phone 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We’ll give you a clear quote before any work starts.
Advice
Your questions about sand mastic in Coldharbour
Is parking an issue for sand mastic in Coldharbour?
Parking in Coldharbour, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Do you cover Coldharbour for sand mastic?
Yes, Coldharbour is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or send us an email and let us know what needs doing.
What’s sand mastic made of?
It’s the traditional filler for the joint round timber windows and doors. It’s made with sand and a linseed-oil-based binder.
Which products do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Is it possible to take out silicone and use sand mastic instead?
Yes. The silicone is cut out and the joint cleaned before the sand mastic goes in.
Is there any odour?
There can be a smell while the sealant cures, which fades as it sets. Opening a window helps.
How long will you be here?
It depends on the size of the job, but most jobs take a few hours for a single window, longer for several. We’ll give you a better idea when we quote.
Can you quote for more than one area?
Yes, we can. Several rooms, windows or areas can go on one quote.
Frames and glazing around Coldharbour
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Rented homes near Canary Wharf station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out. In the older streets around All Saints Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Coldharbour is about 2 miles north of Greenwich, in Greater London. Homes, rented property, offices and hotels in Coldharbour can book us for sand mastic, old or new, large or small. Every job comes with our one-year guarantee. Our Greater London coverage runs to 764 places, and Coldharbour is one of them.
We work across E14, SE10 and E22 for sand mastic. You will find streets such as Canada Square, Simpson's Road and Amsterdam Road. Coldharbour sits on or near the A1206 and A1261, which makes travel easy. Nearby, we also carry out sand mastic in Blackwall (1 mile north-east), London Docklands (1 mile west), Poplar (1 mile north-west), Canary Wharf (1 mile west) and Heron Quays (1 mile west). Further out, we also cover London (4 miles west), City of Westminster (6 miles west), Marylebone (6 miles west), Kensington (8 miles west), St Pancras (5 miles west) and Shoreditch (3 miles north-west).
Landmarks near Coldharbour
We work in homes and buildings around Canary Wharf College 3, Mudchute Park and Farm and Tower Hamlets College. The closest station to Coldharbour is Canary Wharf station, roughly 0.5 miles north-west of the centre. Other landmarks nearby include Old Royal Naval College (1.3 miles south) and Poplar Hospital (0.6 miles north). For a walk, there’s Tower Hill and Lavender Pond.
Surface by surface
Timber door frames
Doors face weather and wear, so their mastic can fail sooner. We rake it out and renew it.
Tenement and terrace windows
Upper-floor windows need access planning. Let us know the floor and we’ll confirm access.