Slough · England
Sand Mastic in Colnbrook
Our applicators work in Colnbrook on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- Mastic that needs renewing before redecorating
- Old sand mastic that has cracked, crumbled or fallen out
- Silicone on a period window that looks wrong
Sand mastic in Colnbrook
We renew sand mastic around sash windows and doors set in stone or brick. Out comes the old, loose mastic, and new mastic is applied and shaped by hand. If you have silicone on a period window that looks wrong and gaps round a timber door in stone or brick, we can help, on stone surrounds, brick reveals and timber door frames alike.
Outdoor sealant needs dry, clean surfaces, so work on frames around Colnbrook is planned for dry weather. Let us know about access to all the frames, upstairs ones included.
You’re covered for a year from the day we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Where
- Colnbrook (SL3)
- Region
- Slough
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Signs you need sand mastic in Colnbrook
Water gets into small cracks in the mastic and loosens it further. Windows facing the weather tend to go first.
These are the problems we are asked about most:
- Old sand mastic that has cracked, crumbled or fallen out
- Mastic worn away on windows facing the weather
- A silicone bead on a sash window that spoils the look
- Draughty sash windows at the surround
Managing a site like Colnbrook Church of England Primary School? Then the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- How long the guarantee is
- How the surfaces are prepared before sealing
- Whether they’re fully insured
- What product goes in the joint
Work for landlords, hotels and businesses
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
Failed sealant is one of the commonest items on a check-out report. Several properties can go on one quote.
How the visit works
On the day, we start by going over the job with you, so you know exactly what we are doing. Surfaces next to the work are protected before we start. The work normally takes a few hours per window, depending on the condition of the joints. Somewhere like Colnbrook needs a little journey planning: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- First, we look at the surrounds with you and agree what needs doing.
- Old, loose mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The mastic is finished to sit tidily against the stone or brick.
How to prepare
- Try not to wet indoor joints just before the visit
- On commercial sites, let us know about site rules
- Let us know about parking restrictions
Getting a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that is easy.
Advice
How to look after the new joints
Looking after new joints is easy, and it makes a real difference:
- Ask a joiner to look at soft timber first
- Do not run silicone over sand mastic
- Make sure water runs off the sill
- Take care around the mastic when scraping paint
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at before trying a quick fix.
Fine cracks show the mastic is starting to fail. Renewing it then is simpler than waiting until it falls out.
Colnbrook homes and the weather
With historic houses such as Frogmore House (about 3 miles west) nearby, there’s older building stock in the area around Colnbrook as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
For an older house near a landmark such as Church of St Thomas, the joint between an old wall and a newer frame is generally the first place rain gets in. Rented homes near Sunnymeads station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Colnbrook is about 4 miles north of Staines-upon-Thames, in Slough. If you need sand mastic in Colnbrook, please phone 0345 464 0079 or email us for a quick quote. We cover Slough from our Crawley base, Colnbrook included. Colnbrook is one of 31 towns and villages in Slough where we work for sand mastic. You can also see our page for London, roughly 19 miles from Colnbrook.
Work in SL3 is quoted and booked the same way as anywhere else. If you need sand mastic at a property on High Street, Rayners Close and Drift Way or anywhere close by, we can help. We also cover Poyle (1 mile south-east), Brands Hill (1 mile west), Horton (1 mile south-west), Stanwell Moor (2 miles south-east) and Ditton (2 miles west). Larger places within reach include Slough (4 miles north-west), Cippenham (5 miles north-west), Chalvey (4 miles north-west), Britwell (5 miles north-west), Upton (3 miles north-west) and Burnham (7 miles north-west).
Landmarks near Colnbrook
Locally, jobs take us to homes and businesses close to Arthur Jacob Nature Reserve, The Red Lion Public House and Langley Grammar School, among other places. For rail, the closest station is Sunnymeads station, roughly 1.7 miles south-west. Well-known places in the area include Windsor Castle (3.4 miles west) and Upton Hospital (3.2 miles north-west). Not far away are Uxbridge Moor and Staines Reservoirs.
Surface by surface
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Period and listed homes
On a listed home or in a conservation area, the right material matters. Sand mastic is often the preferred finish.
Questions from Colnbrook
Is Colnbrook in your area for sand mastic?
Yes, Colnbrook is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we’ll send you a clear quote.
Will you come out to Colnbrook?
Yes, Colnbrook is covered. We work across London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Can you do several jobs on one visit?
Yes, we can. More than one area can be quoted together.
I’m a tenant. Can you help?
Yes, but check with your landlord or agent first. Landlords are often happy for the work to be arranged.
Do I need permission for sand mastic on a listed building?
Your local planning authority is the one to ask. They decide whether consent is needed for work to your windows.
What guarantee comes with the work?
There’s a 12-month guarantee on every job.
Can you replace silicone on a period window with sand mastic?
In most cases. The silicone is cut out and the joint cleaned before the sand mastic goes in.
What do you need from me for a quote?
Where the job is, what the problem is and roughly how big it is. If you can, email a few pictures.
Quotes for sand mastic in Colnbrook
For a quick quote, just ask. The main things that affect it are:
- The old material and how stubborn it is
- The number of rooms or windows
- How easy the joints are to reach
- The type of sealant required
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
What we need to know
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Whether it has been sealed before
- Photos by email, if that’s easy
- Access, such as stairs, a lift or height
- Where the property is
We quote each job on its own, so the first step is telling us about yours. Simply call 0345 464 0079 or send us an email and describe the job and send pictures if you have them.
Towns and villages near Colnbrook
What else we do in Colnbrook
Should I try it myself first?
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.