Hertfordshire · England
Sand mastic for sash & case windows in Gravesend, Hertfordshire
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Gravesend, backed by a 12-month guarantee. Ask us for a quote.
- Tired mastic found when preparing windows for paint
- Gaps round a timber door in stone or brick
- A silicone bead on a sash window that spoils the look
DIY versus a professional finish
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Sand mastic in Gravesend
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditionally, sand mastic is left unpainted and we will advise if you’re redecorating. We work on stone surrounds, period & listed homes and tenement windows, and people most often call us about open joints round the window box and draughts and rain around sash boxes.
Outdoor sealant needs dry, clean surfaces, so work on frames around Gravesend is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
There’s a 12-month guarantee on every job, whatever its size.
- Place
- Gravesend (SG11)
- Wider area
- Hertfordshire
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What affects the cost of sand mastic
Call for a quick quote. The main things that affect it are:
- Whether the work is at height
- The type of sealant required
- The size of the job
- Mould in or behind the old joints
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
What to tell us for a quote
To make quoting easier, let us know:
- How many joints, rooms or windows are involved
- The address or postcode of the job
- What’s wrong with the joints now
- Pictures of the joints, sent by email
We do not publish a price list. Instead, we send you a clear quote for your job. To get started, phone 0345 464 0079 or drop us an email.
Frames and glazing around Gravesend
With historic houses such as Much Hadham Palace (about 3.6 miles south) nearby, there’s older building stock in the area around Gravesend 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. Rainfall in the South East is lower than in much of the UK, 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 Mary, the joint between an old wall and a newer frame is normally the first place rain gets in. If you let a flat or house near Bishops Stortford station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Gravesend is about 4 miles north-west of Bishop's Stortford, in Hertfordshire. For sand mastic in and around Gravesend, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Hertfordshire. We cover 381 towns and villages across Hertfordshire, from the larger towns to small villages. We also work in Chelmsford, about 21 miles from Gravesend.
Here we cover the SG11 postcode area for sand mastic. Close by, we work in Albury (1 mile west), Clapgate (1 mile south-east), Furneux Pelham (2 miles north), Braughing (3 miles west) and Hay Street (3 miles west). Larger places within reach include Stevenage (12 miles west), Bishop's Stortford (4 miles south-east), Welwyn Garden City (14 miles south-west), Hoddesdon (12 miles south-west), Cheshunt (15 miles south-west) and Hertford (11 miles south-west).
Landmarks near Gravesend
Typical jobs here are in homes near The Catherine Wheel pub. Gravesend’s nearest station is Bishops Stortford station, about 4.2 miles south-east. Nearby you’ll also find Herts and Essex Hospital (4.6 miles south-east) and Bishops Stortford Local History Museum (3.1 miles south-east).
How the job changes by surface
Sash and case windows
The mastic round a sash window is on show, so a neat, even finish matters.
Brick reveals
An open joint at a brick reveal lets weather in. New mastic seals the gap.
Why it’s worth doing now in Gravesend
An open joint round the frame lets weather in. Water can get to the frame and the masonry so renewing it early protects the window. In a small place like Gravesend, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
The cost reflects the work involved, not guesswork. That’s why we ask about the job first.
Why us?
- Over 20 years’ experience
- Arbo and Everbuild products
- Experience in homes, commercial sites and hotels
- We never seal over old sealant
Take a look at what affects the cost or what customers say.
More services for Gravesend
Signs you need sand mastic in Gravesend
Sand mastic slowly weathers. It dries out, cracks and loses its grip on the stone or timber.
These are the problems we are asked about most:
- Mastic round period door frames that has failed
- Wind and rain getting in round a sash window
- Gaps between timber frames and stone or brick
- Crumbling sand mastic round a window
For site and facilities teams at buildings such as Albury Church of England Voluntary Aided Primary School, the mastic around its windows and doors needs looking after like any other building’s.
What your quote should include
- Is VAT in the price?
- Whether they seal over old material or remove it
- Whether the sealant suits the joint
- Whether they’re fully insured
Gravesend: your questions answered
Do you cover Gravesend for sand mastic?
Yes. We work across London and the South East, and Gravesend is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job.
I let a flat near Bishops Stortford station. Can you help?
Yes, we work for landlords and letting agents. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Do you work for hotels and businesses?
Yes, regularly. We can plan bigger jobs in stages.
Do you offer different sealant colours?
Yes. Sealants come in white, clear, grey and other colours for many products, and we will agree it with you first.
Are you fully insured?
Yes, we’re fully insured for domestic and commercial work.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Gravesend.
Can I add another job to the visit?
Yes. Several rooms, windows or areas can go on one quote.
The process
We keep the work tidy and contained to the joints we are treating, so you can get on with your day. The job usually takes a few hours per window, depending on the condition of the joints, and we explain the cure time before we leave. In a small place like Gravesend, access is usually the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic isn’t too thick.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Preparing for the visit
- Tell us about any water getting in
- Clear items away from the joints we’re working on
- Mention any tricky access
Getting a quote
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we will explain what’s involved and send you a clear quote.
Related advice
Looking after it afterwards
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Look over the window mastic once a year
- Make sure water runs off the sill
- Do not run silicone over sand mastic
- Renew mastic before redecorating the windows
Leave the new mastic alone while it firms up. It forms a skin fairly soon, but takes longer to harden fully.
Crumbling mastic lets rain into the joint. It can soak into the frame and the surrounding masonry so early renewal protects both.