Hampshire · England
Window & door mastic in Southwick, Hampshire
Window mastic in Southwick from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- A bead that does not match the frame
- Cracked sealant at the sill ends
- Draughts coming in around windows and doors
What window mastic looks like in Southwick
Southwick is within about 2 miles of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That is hard on the mastic around window and door frames, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you look after a building such as King Richard School, its window and door frames need their mastic kept sound, just like a home’s. In the older streets around Church of St James Without the Priory Gate, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Southwick is about 3 miles west of Purbrook, in Hampshire. Homes, rented property, offices and hotels in Southwick can book us for window mastic, old or new, large or small. The work is guaranteed for a year. Our Hampshire coverage runs to 683 places, and Southwick is one of them.
We cover every part of the PO17 postcode area for window mastic and the streets around it. Streets in the area include High Street, North Road West and Castle Road, and we cover them all. Neighbouring places we cover for window mastic include Boarhunt (1 mile west), North Boarhunt (2 miles north-west), Portchester (2 miles south), Hundred Acres (3 miles north-west) and North Fareham (3 miles west). Further out, we also cover Gosport (5 miles south), Havant (5 miles east), Eastleigh (12 miles north-west), Fareham (4 miles west), Horndean (5 miles north-east) and Chandler's Ford (14 miles north-west).
What’s near Southwick
Locally, jobs take us to homes and businesses close to Red Lion Inn. The nearest railway station is Portchester station, roughly 1.9 miles south. Other landmarks nearby include Portchester Castle (2.6 miles south) and Fareham Shopping Centre (3.2 miles south-west). Not far away are Portsdown Hill and St Clair's Meadow.
Window mastic in Southwick
If you can feel air around a shut window, the gap is often at the frame. Resealing that joint can make a room feel noticeably less draughty and quietens the whistle on windy days. If the draught is through the window seals instead, we’ll tell you. Typical jobs include gaps left after new windows were fitted and leaking joints at the ends of sills, on uPVC windows, aluminium frames and patio & French doors.
Outdoor sealant needs dry, clean surfaces, so work on frames around Southwick is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or drop us an email.
- Where
- Southwick (PO17)
- Region
- Hampshire
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Towns and villages near Southwick
More services for Southwick
When something else is needed
We will always be straight with you, so here’s what sealant can’t fix:
- Worn gaskets, brush seals or a door that has dropped
- Misting between the panes of a double-glazed unit (that needs a new unit)
- A frame that has rotted at the joint
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
Joints and surfaces we work on
- uPVC windows
- Aluminium frames
- Timber windows & doors
- Composite doors
- Patio & French doors
- Window sills
How the visit works
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. Most jobs then take most of a day for a typical house, less for a few frames. Somewhere as small as Southwick, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- Frame and wall are cleaned and must be dry before sealing, and primed where the sealant calls for it.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
Getting ready for the visit
- Mention any parking rules near the property
- Where the joints are inside, avoid wetting them before we arrive
- Mention any sign-in or site rules at work premises
Getting a quote
To get a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. You will have a clear quote before work begins.
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Quotes for window mastic in Southwick
The price is agreed before any work begins. It takes into account:
- Whether the work is at height
- The size of the job
- How many areas need sealing
- The old material and how stubborn it is
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What we need to know
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Whether it has been sealed before
- A few pictures by email, if you can
- If it’s domestic, commercial or a hotel
- How we’d reach the joints
Call for a quick quote, or email us if that is easier. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed 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 doesn’t work out, we can still put it right.
When to call us in Southwick
Joints that are too thin or too deep fail early. A skim of sealant over a wide gap soon tears, while a joint packed solid cannot stretch. Backing rod sets the right depth.
It’s worth asking for a quote if you see:
- Old mastic that has gone black or come away
- Cracked or shrunken mastic around the frame
- Damp patches on the reveal after heavy rain
- Draughts coming in around windows and doors
For landlords with property near Portchester station, renewing tired window mastic between tenants heads off draught and damp complaints.
What to look for in a quote
- What happens if they find a problem under the old sealant
- Are they insured?
- The length of the guarantee
- Whether the sealant suits the joint
What happens if it’s left?
Once mastic fails, rain can get between the frame and the wall. Left long enough, it can stain inside walls, spoil plaster and rot wooden frames. A reseal is a much smaller job. Where a wall is exposed, as many are in small places like Southwick, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
The cost depends on the amount of work, how much old material has to come out and access to the work. We give a clear quote before work begins, so you know where you stand.
Why choose Mr Mastic in Southwick
- Tidy, careful work
- Sanitary silicone with an anti-fungal additive in wet areas
- Quality sealants from Arbo and Everbuild
- Homes, businesses and hotels
Take a look at our cost guide or customer reviews.
How the job changes by surface
Composite doors
An exposed front door gets wind-driven rain. We pay most attention there.
Timber windows & doors
On period timber windows, traditional sand mastic is sometimes the better choice. We can talk through the options.
Your questions about window mastic in Southwick
Do you cover smaller places like Southwick?
Yes, Southwick is covered. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Does living near the coast affect window mastic in Southwick?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. Walls facing the sea are generally the first to need attention.
Are you ARBOMaster approved?
Yes. We are an ARBOMaster approved applicator, the approved applicator scheme for Arbo sealants.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Do you have insurance?
Yes. Full insurance covers our work.
Can tenants book the work?
Of course. Check with your landlord; we can send the quote to them too.
Do you have sealant for grey or black windows?
Yes. Grey and black frames get grey or black sealant, and wood-effect frames normally suit brown.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that normally means someone at home.