Hampshire · England
Horndean Window Mastic
Mastic around window and door frames, sills and patio doors for Horndean, backed by a 12-month guarantee. Call for a quick quote.
- Hard, cracked sealant around windows
- Leaking joints at the ends of sills
- Draughts coming in around windows and doors
Horndean questions
Do you work for landlords with property near Rowlands Castle station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we will send you a clear quote.
Do you cover Horndean for window mastic?
Yes, Horndean is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Can you do several jobs on one visit?
Yes, we can. More than one area can be quoted together.
Do I need to be at home?
It depends on the job. For work indoors, someone needs to let us in.
How long should I leave it?
It depends on the product and the temperature. Before we leave, we will tell you the cure time.
Do you work on first-floor windows?
Yes, where they can be reached safely. Tell us about access when you get in touch and we’ll plan for it.
Can you match the sealant to my frames?
Yes, we choose a colour to suit the frame. Grey and black frames get grey or black sealant, and wood-effect frames normally suit brown.
Can you do the inside joint as well?
Yes. Draughts often come through the inside gap too, so sealing both is often worthwhile.
How we handle window mastic in Horndean
Over two decades of sealing frames has taught us which products suit which walls. We are ARBOMaster approved and fully insured, and we give a 12-month guarantee on the work. We work on timber windows & doors, aluminium frames and uPVC windows, and people most often call us about water coming in at the bottom corners of a door and a bead that doesn’t match the frame.
Around Horndean, many houses have gained conservatories, French doors or replacement windows over time. Each one adds more joints to look after, and those joints age at different rates. Sills, frame heads and glazing joints are where leaks normally start.
We guarantee the work for a year. If something is not right with it in that time, tell us and we will put it right.
- Place
- Horndean (PO8, PO7)
- Region
- Hampshire
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Horndean
Other services in Horndean
When to call us in Horndean
Frames are never completely still. Sun on a frame makes it expand, and it contracts again overnight, while the brick or render around it hardly moves. A sealant that can’t keep up eventually tears.
Any of these means the joints need attention:
- Cracked internal joints between frame and plaster
- Cracked sealant at the sill ends
- Rushed sealant from a window installation
- Mastic that’s falling out in pieces
Rented homes near Rowlands Castle station change hands often, and cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
What to look for in a quote
- What the cure time is
- Which sealant they’ll use, and why
- Who turns up on the day
- What happens if the job turns out different
Why it’s worth doing now in Horndean
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished. Draughts from a gap round a frame, damp under a sill or water behind a bath panel all start small, and early is when they’re cheapest and quickest to sort.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will explain what it covers.
Why Horndean clients choose us
- Sanitary silicone with an anti-fungal additive in wet areas
- 180+ five-star Google reviews
- Quality sealants from Arbo and Everbuild
- Fully insured
Take a look at our cost guide or what customers say.
What affects the cost of window mastic
You will get a clear quote before any work starts. It takes into account:
- The number and length of the joints
- The product the joint needs
- How easy the joints are to reach
- How many areas need sealing
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
What to tell us for a quote
You don’t need to know the technical terms. Just tell us:
- Whether it has been sealed before
- How we’d reach the joints
- Pictures of the joints, sent by email
- What’s wrong with the joints now
We quote each job on its own, so the first step is telling us about yours. Just ring 0345 464 0079 or drop us an email with the details, and pictures are welcome.
What we do, step by step
A visit follows a simple pattern: we check the joints, protect the area around them, carry out the job and clear up. Most jobs take a few hours for a few frames, or a day or more for a whole house. For a job in Horndean, we need access to where the work is and somewhere nearby to park. For outside work, let us know about side access, gates and any upper-floor joints.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- Deep gaps get closed-cell backing rod to set the depth.
- A flexible exterior sealant is applied in a colour to suit the frame.
- Every joint is tooled smooth and checked before we leave.
Getting ready for the visit
- Mention any parking rules near the property
- Mention any sign-in or site rules at work premises
- Move anything stored near the joints
Ask for a quote
Asking for a quote is easy: let us know what needs doing and where, and roughly how big it is. A few photos by email make the job easier to understand.
Advice
What window mastic looks like in Horndean
Historic houses like Warblington Castle (about 4.8 miles south-east) are a reminder that the area around Horndean 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 is traditional sand mastic. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you live in an older home near Saint Wilfrid's, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as Horndean Technology College, its window and door frames need their mastic kept sound, just like a home’s.
Horndean is about 7 miles north-east of Portsmouth, in Hampshire. We provide window mastic to householders, landlords and businesses in Horndean. Across Hampshire, we cover 683 places, and Horndean is one of them. We also work in Portsmouth, around 7 miles away.
Our applicators cover all of PO8 and PO7 for window mastic and the streets around it. Streets in the area include London Road, Kings Mede and Causeway Farm, and we cover them all. Horndean sits on or near the A3 and A3(M), which makes travel easy. Other places close to Horndean include Lovedean (1 mile west), Wecock Farm (1 mile south-west), Catherington (2 miles north), Anmore (2 miles west) and Denmead (2 miles west). We also work in nearby towns such as Gosport (9 miles south-west), Havant (3 miles south), Eastleigh (15 miles west), Fareham (9 miles south-west), Hedge End (13 miles west) and Petersfield (7 miles north-east). Horndean is one of the larger places we cover in Hampshire.
Landmarks near Horndean
We work in homes and buildings around Horndean Infant School and Red Lion Inn. The nearest railway station is Rowlands Castle station, roughly 2.6 miles south-east. Well-known places in the area include Havant War Memorial Hospital (3.8 miles south) and Clanfield Earthwork (3 miles north-east). Not far away are Windmill Hill and Southmoor Nature Reserve.
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
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 fails, we can still redo it.
Keeping the joints in good condition
Simple care keeps the joints in good condition. We recommend:
- Keep jet washers away from the mastic
- Keep paint off silicone joints
- Make sure the drainage slots are not blocked
- Air rooms to keep condensation down around windows
Most silicone sealants will not take paint, so if you’re planning to paint the frames or walls, tell us beforehand. We can use a paintable sealant where that matters.
On timber windows, water behind the joint can lead to rot. Rotten timber needs a joiner, not a sealant, so it pays to reseal before that happens.
Landlord and commercial work in Horndean
If you manage several properties in or around Horndean, several properties can go on one quote. Just tell us the addresses and what each one needs.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.