Hampshire · England
Dean Window Mastic
We cover Dean for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly.
- Whistling draughts around closed windows
- Gaps where the sill meets the wall
- White mastic on grey or black frames
Common questions in Dean
Will you come out to Dean?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near Botley station?
Yes, we work for letting agents and landlords. Just call 0345 464 0079 or email us and tell us about the property, and we’ll give you a clear quote.
Are you an approved applicator?
Yes. We are approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint before we leave.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. Once we have agreed the job, you don’t need to watch us work.
Will it make a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
Do you have sealant for grey or black windows?
Yes. Anthracite grey, black, brown and white cover most frames, with clear as an option.
How we handle window mastic in Dean
If you can feel air around a shut window, the gap is often at the frame. A new joint stops the air getting through and quietens the whistle on windy days. If the draught is through the window seals instead, we will tell you. If you are dealing with whistling draughts around closed windows and gaps where the sill meets the wall, we can help.
Around Dean, many homes face open ground, so their windows and doors take the full weather. Exposed frames and sills lose their mastic sooner than sheltered ones.
You get a one-year guarantee, the same in Dean as everywhere else we work.
- Location
- Dean (SO32)
- Region
- Hampshire
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
So the new joints stay in good condition:
- Check the mastic once a year
- Wipe condensation off the frames
- Clear any debris from frame drain holes
- Clean frames with a soft cloth and soapy water
A yearly look round the frames is enough. Cracks and lifting edges are easy to spot early, and if anything looks wrong, just phone 0345 464 0079 or send us an email.
Wet, windy weather is when failed mastic shows itself, but sealant goes on best when frames and walls are dry. Sorting cracked mastic early means the joint is sound before the bad weather.
What we are called out for in Dean
A lot of older mastic was never designed to stay flexible. Once it has hardened, the frame’s movement tears it from the wall, leaving a hairline gap down one side.
The problems people usually mention when they call include:
- Gaps where the sill meets the wall
- Black, perished sealant on frames
- Sealant in the wrong colour for the frame
- Gaps left after new windows were fitted
If you live in an older home near Church of St Peter, the joint between an old wall and a newer frame is normally the first place rain gets in.
Questions to ask before booking
- Is the old sealant removed completely?
- What insurance they hold
- How long the guarantee is
- When the joint can take water or movement
Dean homes and the weather
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.
Rented homes near Botley station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. Managing a site like Bishops Waltham Infant School? Then the mastic around its windows and doors needs looking after like any other building’s.
Dean is about 6 miles north-east of Hedge End, in Hampshire. Whether you are in the middle of Dean or further out, window mastic is available for homes and businesses alike. 683 places in Hampshire are on our list, from the larger towns to small villages. For nearby work, see our Southampton page (9 miles or so).
We cover every part of SO32 for window mastic. That includes homes and businesses on Dean Lane, Little Ashton Lane and Limekiln Lane and the roads around them. If you’re just outside Dean, we cover The Hangers (1 mile east), Upper Swanmore (2 miles south-east), Swanmore (2 miles south), Hill Grove (2 miles south-east) and Droxford (3 miles east). We also work in nearby towns such as Winchester (8 miles north-west), Gosport (12 miles south), Havant (12 miles south-east), Eastleigh (6 miles west), Fareham (8 miles south) and Horndean (9 miles south-east).
Around Dean
In Dean, that means homes and buildings near Swanmore College of Technology and the streets around them. The closest station to Dean is Botley station, roughly 4.6 miles south-west. Nearby you’ll also find Bishop's Waltham Museum (1.4 miles south-west). Not far away are Bishops Waltham Branch LNR and Beacon Hill.
Landlord and commercial work in Dean
If you manage several properties in or around Dean, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs.
We also work for property managers and facilities teams in Dean and across Hampshire. We can quote a run of properties together, and we’re fully insured for the work.
How the visit works
On the day, we look over the joints with you first. Surfaces next to the work are protected before work begins. Most jobs take anything from an hour or two to a full day, depending on how many frames there are. In a small place like Dean, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- We clear up and check every joint is fully closed.
Getting ready for the visit
- Let us know about stairs, lifts or work at height
- For business premises, tell us about site rules or sign-in
- Keep children and pets away from the work area
How to get 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’s easy.
Read more
Towns and villages near Dean
Also in Dean
What the job involves on each surface
Timber windows & doors
Where timber has rotted at the joint, it needs repairing first. If we find rot, we’ll tell you before going ahead, as a joiner will need to deal with it.
Patio & French doors
Patio and French doors have the longest joints on most houses. The threshold and the bottom corners take the most water, so they get particular care.
Why deal with it now?
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished, and it’s easier while the walls are being worked on anyway. Older cottages and farmhouses around Dean can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
We don’t show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
Why choose Mr Mastic in Dean
- Full insurance on every job
- Old sealant always removed completely
- Colour picked to suit the job
- 180+ five-star Google reviews
Read our cost guide and our reviews.
DIY sealant or a professional job?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is.