Portsmouth · England
Sand mastic for sash & case windows in Copnor, Portsmouth
Professional sand mastic in and around Copnor, with every bit of old sealant taken out first and a 12-month guarantee.
- Mastic dropping out of the joint
- Patchy fillers round a sash window
- A silicone bead on a sash window that spoils the look
Sand mastic for homes and businesses in Copnor
Our applicators renew the sand mastic around sash and case windows and doors in stone and brick. Out comes the old, loose mastic, the joint is prepared and new mastic is shaped by hand. If you have failed mastic on an exposed elevation and draughty sash windows at the surround, we can help, whatever the surface.
In smaller places like Copnor, homes range from older cottages to newer houses, with windows to match: timber, uPVC and aluminium. Each frame material needs the right sealant against the right wall.
All of our work is guaranteed for twelve months, and the guarantee is the same wherever you are.
- Place
- Copnor (PO3, PO2, PO1)
- Wider area
- Portsmouth
- Guarantee
- A year, on every job
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
When to call us in Copnor
Previous repairs in cement or silicone often trap water or crack away. They don’t move with the timber and we normally remove them.
Any of these means the joints need attention:
- Silicone on a period window that looks wrong
- Weathered mastic on the most exposed windows
- Gaps where the frame meets the masonry
- Mastic that needs renewing before redecorating
For landlords with property near Fratton station, any sash windows need sound mastic to keep draughts and rain out.
What your quote should include
- How much experience the applicator has
- Whether the sealant suits the joint
- How the surfaces are prepared before sealing
- Are they insured?
Copnor homes and the weather
Copnor is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on the mastic around older windows and doors, which can dry out and crack sooner where a building faces the weather. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
In the older streets around Church of St Alban, the joint between an old wall and a newer frame is usually the first place rain gets in. Managing a site like Westover Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Copnor is about 1 mile east of Portsmouth, in Portsmouth. Every kind of property in Copnor is covered for sand mastic. The work is guaranteed for a year. Copnor is one of 19 places in Portsmouth where we work.
We cover every part of PO3, PO2 and PO1 for sand mastic and the streets around it. Streets in the area include New Road, Lynn Road and Byron Road, and we cover them all. Copnor sits on or near the A288. Other places close to Copnor include Baffins (1 mile south-east), Kingston (1 mile south), Portsmouth (1 mile west), Fratton (1 mile south-west) and North End (1 mile north-west).
Near you in Copnor
Locally, jobs take us to homes and businesses close to The Jolly Taxpayer pub, Alexandra Park and St Edmund's Catholic School and the streets around them. Copnor’s nearest station is Fratton station, roughly 1.1 miles south-west. Other landmarks nearby include The Bridge Shopping Centre (1.1 miles south-west) and St Mary's Hospital (0.7 miles south). Not far away are Milton Locks and Portsdown Hill.
Other services in Copnor
The process
We keep the work tidy and contained to the area we’re working on. Expect the work to take a few hours for a single window, longer for several, and we explain the cure time before we leave. For a job in Copnor, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We check each window surround and the condition of the joint.
- 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
- Try not to wet indoor joints just before the visit
- Let us know about earlier repairs to the joints
- Tell us about any water getting in
Get a quote
If you’re in Copnor and need sand mastic, phone 0345 464 0079 or send us an email. Tell us what the problem is and where, and we’ll agree the price before any work begins.
Related advice
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.
Hotels need rooms back in use, so the work can be planned room by room. We have worked in hotels as well as homes and businesses.
DIY versus a professional finish
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What affects the cost of sand mastic
We don’t publish a price list. The quote depends on:
- How easy the joints are to reach
- How much old sealant there is and how hard it is to remove
- Which sealant suits the joint
- How many rooms, windows or areas are involved
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or email us and we will talk you through it.
Helping us quote
Photos help, but a description is a good start. Try to tell us:
- Where the property is
- Whether it’s a home or a business
- Any previous sealing or DIY work
- What’s wrong with the joints now
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is.
What the job involves on each surface
Sash and case windows
On a sash window, the mastic joint shows on the outside so we finish it carefully.
Brick reveals
Gaps between frame and brick let in rain and draughts. New mastic seals the gap.
Copnor: your questions answered
I let a flat near Fratton station. Can you help?
Yes, landlords and agents are among the people we work for. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Does the coastal weather in Copnor affect outside sealant?
Near the sea, outside joints face more wind, rain and salt than they would inland, so preparation and the right sealant matter all the more. Walls facing the sea are normally the first to need attention.
Do you take out the old sealant first?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Do you hold any approvals?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
How long does sand mastic take to go off?
It skins over fairly quickly but takes longer to harden fully. We will tell you what to expect for your job.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done and we’ll quote it together.
Do you work in Copnor?
Yes. From our base in Crawley, we cover South East England, London and all of Scotland, Copnor included.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that usually means someone at home.
Honest limits
New sealant can’t fix everything, and we’d rather say so up front. It won’t solve:
- Damaged stone surrounds
- Broken panes
- Timber that has rotted
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
Surfaces we seal
- Tenement windows
- Sash and case windows
- Timber door frames
- Stone surrounds
- Brick reveals
- Period & listed homes