West Sussex · England
Sand mastic for sash & case windows in Crawley Down, West Sussex
Our applicators work in Crawley Down on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Old sand mastic that has cracked, crumbled or fallen out
- Draughty sash windows at the surround
- Window mastic to renew ahead of painting
How we handle sand mastic in Crawley Down
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditionally, sand mastic is left unpainted, so ask us before you decorate. If you’re dealing with cement or filler used on old window joints that has cracked and mastic round period door frames that has failed, we can help, whatever the surface.
Around Crawley Down, conservatories, garden rooms and patio doors are often part of the house. Those joints need the same attention as the main windows, and any older timber or sash windows need a sealant that suits them.
All of our work is guaranteed for twelve months.
- Place
- Crawley Down (RH10)
- Region
- West Sussex
- Cover
- One year on every job
- Quote
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
To keep the joints looking good and working properly:
- Take care around the mastic when scraping paint
- Plan mastic work ahead of painting
- Ask the planning authority about consent for listed or conservation-area homes
- Look over the window mastic once a year
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall so early renewal protects both.
Towns and villages near Crawley Down
What else we do in Crawley Down
Should I try it myself first?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
How the job changes by surface
Timber door frames
Doors face weather and wear and the mastic can crack early. We rake it out and renew it.
Brick reveals
An open joint at a brick reveal lets weather in. New mastic seals the gap.
What sand mastic looks like in Crawley Down
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Saint Hill Manor (about 2.4 miles south-east) nearby, there’s older building stock in the area around Crawley Down as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
Letting a property close to East Grinstead station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about. If you live in an older home near All Saints Parish Church, the joint between an old wall and a newer frame is generally the first place rain gets in.
Crawley Down is about 3 miles west of East Grinstead, in West Sussex. Wherever you are in the RH10 postcode area, we can carry out sand mastic at your property. Crawley Down is one of 371 towns and villages in West Sussex where we work.
Our applicators cover all of the RH10 postcode area for sand mastic. You’ll find streets such as Station Road, Forest Close and Burleigh Way. Other places close to Crawley Down include Furnace Wood (1 mile north), Snow Hill (1 mile north), Turners Hill (1 mile south), Domewood (1 mile north) and Felbridge (2 miles north-east). Further out, we also cover Crawley (5 miles west), Horsham (11 miles west), Haywards Heath (9 miles south), Burgess Hill (12 miles south), East Grinstead (3 miles east) and Broadfield (6 miles west).
Landmarks near Crawley Down
Around Crawley Down, our work takes us to homes and buildings near Imberhorne School and the streets around them. Crawley Down’s nearest station is East Grinstead station, about 2.5 miles east. Other landmarks nearby include Queen Victoria Hospital (3.5 miles east) and Effingham Park Motor Museum (1.4 miles north-west). The countryside around Crawley Down includes Hedgecourt Lake.
FAQs for Crawley Down
I let a flat near East Grinstead station. Can you help?
Yes. We work for letting agents and landlords as well as homeowners. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Is Crawley Down within the area you cover?
Yes, we do. We work across London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Do I need permission for sand mastic on a listed building?
Yes, it’s worth checking. Your local planning authority can say if consent is needed for work on a listed home or in a conservation area.
Do the sealants smell?
There can be a smell while the sealant cures. Ventilation helps.
Is it OK to seal over old sealant?
No. The old sealant always comes out first, so the new sealant bonds properly.
Can you quote for more than one area?
Yes. Just list everything you need and we’ll quote it together.
Where do you work from?
Our base is Crawley, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Can you match the sealant colour?
Generally, yes. White, clear and grey are common, and other colours are available, and we will agree it with you first.
Quotes for sand mastic in Crawley Down
We quote each job individually. These are the things that affect it:
- Mould in or behind the old joints
- The number of rooms or windows
- Whether old sealant or filler has to be cut out
- Whether the work is at height
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You will know the price before we begin.
What to tell us for a quote
Before you ask for a quote, have a think about:
- If someone has resealed it before
- The type of property
- How many joints, rooms or windows are involved
- The problem you’ve noticed
We don’t publish a price list. Instead, we send you a clear quote for your job. To get started, phone 0345 464 0079 or email us.
How the visit works
We work through the job in order: protect, prepare, seal, tidy. For most jobs that takes a few hours for a single window, longer for several, and the area is left clean. In a smaller place like Crawley Down, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- We start by checking each surround and agreeing the joints to renew.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Before we arrive
- Mention any sign-in or site rules at work premises
- Tell us about any previous sealing or DIY attempts
- Tell us about any water getting in
Getting a quote
For a quote, phone 0345 464 0079 or send us an email with the location and a short description of the problem. We will send you a clear quote before any work starts.
Related advice
What we can’t put right
A few problems are outside what sealant work can do:
- Decisions on consent for listed homes
- Putty and glazing repairs
- Sash cords, weights and draught-proofing of the sashes
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Sash and case windows
- Stone surrounds
- Period & listed homes
- Tenement windows
- Timber door frames
- Brick reveals
Leave it or put it right?
New mastic over crumbling mastic will not hold. Raking out and preparing the joint gives it a sound base so the new mastic stays put. In a smaller place like Crawley Down, wherever a wall is exposed, a failed outside joint is a real source of damp. Indoors, a failed seal lets water into floors and panels as it would anywhere.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Why book with us
- Fully insured
- Domestic, commercial and hotel work
- 4.9 on Google from 180+ five-star reviews
- Neat joints and a tidy finish
See what affects the cost or our reviews.