West Sussex · England
Sand Mastic in Colwood
Our applicators work in Colwood 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 and a one-year guarantee.
- Old sand mastic that has cracked, crumbled or fallen out
- A silicone bead on a sash window that spoils the look
- Gaps between timber frames and stone or brick
Should I try it myself first?
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Sand mastic for homes and businesses in Colwood
We work across Colwood renewing sand mastic on sash windows and doors. Every joint is cleaned out and filled by hand, finished to suit the masonry. If you’re dealing with mastic worn away on windows facing the weather and draughty sash windows at the surround, we can put it right, on tenement windows, brick reveals and timber door frames alike.
Homes in small places like Colwood 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.
We guarantee the work for a year. If something isn’t right with it in that time, tell us and we’ll put it right.
- Location
- Colwood (RH17)
- Region
- West Sussex
- Guarantee
- 12 months on all our work
- Quote
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What we do, step by step
At the end, we look at the finished work together and tell you how long to leave it. The visit itself generally takes a few hours per window, depending on the condition of the joints, depending on the size of the job. Somewhere like Colwood needs a little journey planning: 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.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Clear the area around the work
- Try not to wet indoor joints just before the visit
Getting a quote
To get a quote, ring 0345 464 0079 or email us and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.
Related advice
Colwood homes and the weather
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Tyes Place (about 3.4 miles north-east) are a reminder that the area around Colwood has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
Historic houses such as Tyes Place, about 3.4 miles north-east, show how far back building around Colwood goes, and older homes nearby need a sealant that suits their walls.
Colwood is about 5 miles north-west of Burgess Hill, in West Sussex. Whether you are in the middle of Colwood or further out, we cover sand mastic for every kind of property. We cover 371 towns and villages across West Sussex, from the larger towns to small villages. Our Crawley page covers work nearby.
Every address in RH17 is within our area for sand mastic, from the main roads to the quietest streets. Whether your property is on Earwig Lane and Cross Colwood Lane or anywhere close by, we can help. If you’re just outside Colwood, we cover Crabtree (1 mile north-west), Lower Beeding (2 miles north-west), Slaugham (3 miles north), Plummers Plain (3 miles north) and Monk's Gate (3 miles north-west). Within a short drive, we also cover Crawley (8 miles north), Horsham (6 miles north-west), Worthing (15 miles south-west), Haywards Heath (6 miles east), Burgess Hill (5 miles south-east) and East Grinstead (13 miles north-east).
Near you in Colwood
Locally, jobs take us to homes and businesses close to Leonardslee and the streets around them. Other landmarks nearby include The Dene Hospital (3.8 miles south-east) and Cuckfield Museum (3.7 miles east). Open spaces near Colwood include Blunts Wood and Paiges Meadow.
Honest limits
To be straight with you, there are a few things sealant will not fix:
- Whether work needs listed building consent
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sash cords, weights and draught-proofing of the sashes
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think before booking.
Joints and surfaces we work on
- Timber door frames
- Brick reveals
- Stone surrounds
- Sash and case windows
- Period & listed homes
- Tenement windows
What the job involves on each surface
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. Sand mastic is shaped by hand to suit.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We can do one window or several.
Why act early in Colwood
If you are redecorating, renew the mastic first. Painting over failed mastic doesn’t seal it, and the new mastic is traditionally left unpainted. Older cottages and farmhouses around Colwood can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are unsure, call 0345 464 0079 or drop us an email and we will give you an honest view and a quote.
Why us?
- Any old sealant cut out fully, not covered over
- Neat joints and a tidy finish
- Fully insured
- Every job guaranteed for a year
Take a look at what affects the cost or customer reviews.
Landlords, agents and businesses in Colwood
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
If you manage several properties in or around Colwood, several properties can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
Your questions about sand mastic in Colwood
Is there a guarantee on sand mastic in Colwood?
Every job comes with our one-year guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Do you cover Colwood for sand mastic?
Yes. We work across London and the South East, and Colwood is part of that. Just phone 0345 464 0079 or send us an email with a few details of the job, and we will give you a clear quote.
I rent my home. Can I book you?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Which is right for my windows, sand mastic or modern sealant?
We’ll help you decide. Sand mastic suits many period homes, and modern sealants suit newer frames.
Is it messy?
We keep the work tidy. We protect what’s around the joints.
Where are you based?
Our base is Crawley, with over 20 years’ experience. We work across South East England, London and Scotland.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Do you offer different sealant colours?
We help you choose a colour that suits. The product needed can limit the range.
When to call us in Colwood
Shallow joints are a common cause. Mastic that is too thin cracks and drops out so we make sure the new mastic is the right thickness.
The most common problems we see are:
- Draughts and rain around sash boxes
- Old cement repairs round a window that have failed
- Open joints round the window box
- Silicone on a period window that looks wrong
In and around Colwood, as anywhere, good sand mastic starts with a clean, dry, properly prepared joint.
Questions to ask before you book
- How hidden problems are handled
- Is the old sealant removed completely?
- How the surfaces are prepared before sealing
- Are they insured?