West Sussex · England
Coolham Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homeowners, landlords and businesses in Coolham. Fully insured, ARBOMaster approved and guaranteed for a year.
- Cracked mastic round a front door frame
- Gaps where the frame meets the masonry
- Tired mastic found when preparing windows for paint
Sand mastic for homes and businesses in Coolham
Sand mastic suits most period window surrounds. Newer frames generally get a flexible sealant instead and we will explain which is best for yours. We’re often asked to deal with tired mastic found when preparing windows for paint and wind and rain getting in round a sash window, on tenement windows, sash and case windows and stone surrounds.
Homes in small places like Coolham often stand in the open, with little to shelter their windows from wind and rain. That exposure dries out and cracks the mastic around frames and sills faster.
Each job carries a 12-month guarantee, large or small.
- Place
- Coolham (RH13)
- Wider area
- West Sussex
- Guarantee
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Coolham homes and the weather
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Letting a property close to Billingshurst station? Then any sash windows need sound mastic to keep draughts and rain out. For site and facilities teams at buildings such as William Penn School, larger buildings have plenty of frames, and the mastic around each one ages.
Coolham is about 6 miles south-west of Horsham, in West Sussex. From the centre of Coolham to the outskirts, we cover sand mastic for every kind of property. Across West Sussex, we cover 371 places, Coolham among them. There’s also a page for Crawley, about 12 miles away.
We cover every part of the RH13 postcode area for sand mastic and the streets around it. We cover properties on Coolham Road and West Chiltington Lane and the roads around them. If you’re just outside Coolham, we cover Goose Green (3 miles south), Gay Street (3 miles south-west), Adversane (3 miles west), North Heath (3 miles west) and West Chiltington (3 miles south-west). We also work in nearby towns such as Crawley (12 miles north-east), Horsham (6 miles north-east), Worthing (12 miles south), Haywards Heath (13 miles east), Burgess Hill (12 miles east) and Littlehampton (14 miles south-west).
Local landmarks in Coolham
Locally, jobs take us to homes and businesses close to The Selsey Arms Public House, among other places. For rail, the closest station is Billingshurst station, roughly 2.4 miles north-west of the centre. Other landmarks nearby include Christs Hospital School Museum (3.9 miles north-east). Not far away are Knepp Wildland.
Looking after it afterwards
Good habits help new joints last longer. A few tips:
- Leave the new mastic unpainted
- Check with your local planning authority if your home is listed
- Plan mastic work ahead of painting
- Look over the window mastic once a year
Keep gutters and sills clear so water runs away from the surround. Water sitting against the mastic shortens its life.
Sound mastic protects the frame. Failed mastic lets water reach the timber and timber that stays wet can rot.
What else we do in Coolham
For landlords and businesses
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we’ll give you a quote.
From a single let to a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Leave it or put it right?
Draughts round a sash window aren’t always the sashes. Gaps between the frame and the wall can be just as bad, and renewing the mastic closes them. Where a wall is exposed, as many are in small places like Coolham, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
What you get with us
- Trusted Arbo and Everbuild sealants
- We never seal over old sealant
- Homes, businesses and hotels
- Tidy, careful work
See how sealant jobs are priced and our reviews.
When it isn’t the sealant
We’ll always be straight with you, so here’s what new sealant won’t do:
- Timber that has rotted
- Cracked or broken glass
- Sashes that need overhauling
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
Joints and surfaces we work on
- Stone surrounds
- Brick reveals
- Period & listed homes
- Timber door frames
- Sash and case windows
- Tenement windows
How the visit works
Before we leave, we go over the finished joints with you and tell you how long to leave it. The visit itself usually takes anything from a few hours to a full day, depending on how many windows, depending on the size of the job. For a village or hamlet like Coolham, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
- Tell us about any previous sealing or DIY attempts
Get a quote
Need a quote? Please phone 0345 464 0079 or email us and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Read more
Surface by surface
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. We renew it the same way as on windows.
Sash and case windows
Most of our sand mastic work is on sash windows. Each joint round the box is raked out and renewed.
Common questions in Coolham
Is Coolham in your area for sand mastic?
Yes. Our work covers London and the South East, and Coolham is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Will you come out to Coolham?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can I paint the new mastic?
It’s traditionally left unpainted, as guidance on traditional windows advises. Ask us before decorating.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done and we’ll quote it together.
Is the work guaranteed?
Every job comes with our 12-month guarantee.
Can you match the sealant colour?
We’ll suggest a colour to suit the surroundings. The product needed can limit the range.
Do you remove the old sealant?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
What’s sand mastic made of?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
Signs you need sand mastic in Coolham
Decorating can disturb tired mastic. Many people find it crumbling when they prepare the windows.
These are the problems we are asked about most:
- Tired mastic found when preparing windows for paint
- Open joints round the window box
- Draughty sash windows at the surround
- Cracked mastic round a front door frame
If you live in an older home near St Mary's Mission Church, the joint between an old wall and a newer frame is generally the first place rain gets in.
What your quote should include
- Whether they’re fully insured
- When the joint can take water or movement
- How the surfaces are prepared before sealing
- Which sealant they’ll use, and why