West Sussex · England
Rock Sand Mastic
Sand mastic for Rock and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Gaps round a timber door in stone or brick
- A silicone bead on a sash window that spoils the look
- Draughty sash windows at the surround
Work for landlords, hotels and businesses
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we’ll give you a quote.
How we handle sand mastic in Rock
Old sand mastic cracks, crumbles and falls out over time and gaps open up round the frame. We rake it out and renew it so the surround looks right again. We work on sash and case windows, period & listed homes and brick reveals, and people most often call us about old sand mastic that has cracked, crumbled or fallen out and failed mastic on an exposed elevation.
Outdoor sealant needs dry, clean surfaces, so work on frames around Rock is planned for dry weather. Let us know about access to all the frames, upstairs ones included.
Every job comes with a 12-month guarantee.
- Place
- Rock (RH20)
- Region
- West Sussex
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
How it works
Before we leave, we go over the finished joints with you. The visit itself normally takes a few hours for a single window, longer for several, depending on the size of the job. Somewhere like Rock needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each surround and agreeing the joints to renew.
- We rake out the old mastic and clean the joint.
- We pack any deep gaps so the mastic sits at the right depth.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The mastic is finished to sit tidily against the stone or brick.
Preparing for the visit
- Keep children and pets away from the work area
- Tell us if parking is tricky
- Let us know about stairs, lifts or work at height
Ask for a quote
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job.
Read more
Towns and villages near Rock
What else we do in Rock
DIY versus a professional finish
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
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 doesn’t work out, we can still put it right.
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Look over the window mastic once a year
- Avoid patching sand mastic with silicone
- Keep sills and gutters clear so water drains away
- Have rotten timber repaired before new mastic goes in
Make sure water drains away from the window surround. Water sitting against the mastic shortens its life.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.
When something else is needed
New sealant can’t fix everything, and we’ll tell you before we start. It won’t solve:
- Timber that has rotted
- Broken panes
- Whether work needs listed building consent
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think.
Surfaces we seal
- Period & listed homes
- Stone surrounds
- Timber door frames
- Brick reveals
- Sash and case windows
- Tenement windows
Questions from Rock
Do you cover smaller places like Rock?
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 you do sand mastic in Rock?
Yes, Rock is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job, and we will give you a clear quote.
Can you match the sealant colour?
We’ll suggest a colour to suit the surroundings. The choice depends on the product the joint needs.
Where is Mr Mastic based?
We are a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Can new sealant go over the old?
No. New silicone won’t bond to old silicone, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
How long does the job take?
It depends on the size of the job, but as a guide it takes a few hours for a single window, longer for several. We’ll give you a better idea when we quote.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Is it possible to paint over sand mastic?
It’s traditionally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
How we quote for sand mastic
Every job gets its own quote. This is what makes a difference:
- The old material and how stubborn it is
- The product the joint needs
- How many areas need sealing
- The number and length of the joints
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please call 0345 464 0079 or send us an email.
Helping us quote
To make quoting easier, let us know:
- The rough size of the job
- Whether it has been sealed before
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
Call for a quick quote, or email us if that’s easier. Tell us about the joints that need doing and we will explain what’s involved and send you a clear quote.
Windows and doors in Rock
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 Parham House (about 3.9 miles west) nearby, there’s older building stock in the area around Rock as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
For site and facilities teams at buildings such as St Mary's CofE Primary School, the mastic around its windows and doors needs looking after like any other building’s. Homes close to The Parish Church of St Mary include some older properties, and the joint between an old wall and a newer frame is usually the first place rain gets in.
Rock is about 6 miles north of Worthing, in West Sussex. Homes, rented property, offices and hotels in Rock is covered for sand mastic. Every job comes with our 12-month guarantee. We cover 371 towns and villages across West Sussex, large and small. Brighton is on our list too, around 13 miles away.
Postcode districts we cover here for sand mastic: RH20. You will find streets such as Old London Road, London Road and Lamorna Close, all of which we cover. If you are just outside Rock, we cover Washington (1 mile south), Heath Common (1 mile north-west), Sullington (1 mile west), Warminghurst (2 miles north) and Storrington (2 miles west). Within a short drive, we also cover Horsham (11 miles north), Worthing (6 miles south), Bognor Regis (15 miles south-west), Haywards Heath (15 miles north-east), Burgess Hill (12 miles east) and Littlehampton (9 miles south-west).
Near you in Rock
Locally, jobs take us to homes and businesses close to Rydon Community College and The Frankland Arms Public House. Nearby you’ll also find The Storrington And District Museum (1.9 miles west). The countryside around Rock includes Chanctonbury Hill.
What the job involves on each surface
Brick reveals
We rake out the old mastic and pack deep voids before pointing.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.