Hampshire · England
Window & door mastic in Longstock, Hampshire
Our applicators work in Longstock on mastic around window and door frames, sills and patio doors. Old material cut out, joints cleaned and sealed neatly and a 12-month guarantee.
- A bead that doesn’t match the frame
- Damp patches on the reveal after heavy rain
- Cold air getting in at the frame edge
Frames and glazing around Longstock
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Test Valley School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
Longstock is about 5 miles south of Andover, in Hampshire. From the centre of Longstock to the outskirts, we cover window mastic for every kind of property. Our Hampshire coverage runs to 683 places, and Longstock is one of them. You can also see our page for Southampton, about 15 miles away.
Every address in SO20 is covered for window mastic, from the main roads to the quietest streets. Other places close to Longstock include Leckford (1 mile east), Stockbridge (1 mile south), Fullerton (2 miles north-east), Cottonworth (2 miles north-east) and Chilbolton (3 miles north-east). We also work in nearby towns such as Winchester (9 miles south-east), Eastleigh (13 miles south-east), Andover (5 miles north), Totton (15 miles south), Chandler's Ford (11 miles south-east) and Romsey (10 miles south).
What’s near Longstock
In Longstock, that means homes and buildings near Longstock Park and The Peat Spade Public House. A little further out are Andover War Memorial Hospital (5.8 miles north). Not far away are Mill Lake.
Window mastic in Longstock, done properly
There are two joints on most windows. The external joint is the weather seal; inside, the joint between frame and plaster stops draughts and tidies the reveal. Either or both can be done. Common call-outs are for leaking joints at the ends of sills and draughts coming in around windows and doors, across window sills, timber windows & doors and patio & French doors.
In a village or hamlet like Longstock, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, and sometimes a traditional sand mastic is the better choice.
There’s a 12-month guarantee on every job.
- Place
- Longstock (SO20)
- Region
- Hampshire
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Towns and villages near Longstock
More services for Longstock
The process
We keep the work tidy and contained to the area we are working on, so you can carry on as normal. The job usually takes anything from an hour or two to a full day, depending on how many frames there are, and we tell you how long to leave it before we go. In a small place like Longstock, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away, along with any loose debris.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Backing rod fills deep voids and the sealant goes in on top.
- We tool the joint so water runs off, then clear up.
Preparing for the visit
- On commercial sites, let us know about site rules
- Keep pets and children clear of the area while we work
- Mention any tricky access
Get a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved and send you a clear quote.
Related advice
For landlords and businesses
We work for landlords and agents as well as householders. Resealing between tenancies keeps a property looking cared for.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Aftercare tips
To keep the joints looking good and working properly:
- Repaint timber before it’s bare
- Wipe condensation off the frames
- Make sure the drainage slots aren’t blocked
- Avoid harsh chemicals near the mastic
Keep sill grooves and drainage slots clear, so water can run away instead of sitting against the joint.
A failed joint lets water into the wall a little at a time. You might not see it until plaster blows or a damp patch appears inside. Catching it early keeps the fix to a reseal.
When it is not the sealant
Sealant isn’t the answer to every problem, and we’ll tell you before any work starts. It won’t solve:
- Worn gaskets, brush seals or a door that has dropped
- Rotten timber, which needs a joiner first
- A sash or casement that will not close properly
If in doubt, call 0345 464 0079 or email us and we will say what we think before you book.
Joints and surfaces we work on
- Window sills
- uPVC windows
- Composite doors
- Patio & French doors
- Aluminium frames
- Timber windows & doors
DIY versus a professional finish
If you are set on DIY, put the effort into 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.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
When to call us in Longstock
On timber frames, paint and putty build up around the joint. Mastic painted over many times cracks with the paint, and the wood moves with damp as well as heat.
The problems people normally mention when they call include:
- Damp patches on the reveal after heavy rain
- Cracked internal joints between frame and plaster
- Cold air getting in at the frame edge
- Gaps left after new windows were fitted
In the older streets around Church of St Mary, the joint between an old wall and a newer frame is generally the first place rain gets in.
Before booking anyone
- What happens if they find a problem under the old sealant
- Whether all the old sealant comes out first
- Are they insured?
- How much experience the applicator has
Longstock questions
Will you come out to Longstock?
Yes, Longstock is covered. We work across London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
What guarantee comes with window mastic in Longstock?
All our work, in Longstock and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned before resealing.
Can new sealant go over the old?
No. Fresh sealant doesn’t stick to old sealant, and it traps any mould or water underneath. It all has to come out first.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. For inside work, that normally means someone being in.
What sealant do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We’ll tell you what we’re using and why.
Do you have insurance?
Yes. We are fully insured, and we can confirm the details when we quote.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Different surfaces, different methods
Window sills
Every drop off the glass ends up on the sill, so the joints at each end and underneath matter. Each is cleaned out and resealed.
Timber windows & doors
Soft or rotten wood can’t be sealed successfully. If we find rot, we’ll tell you before going ahead, as a joiner will need to deal with it.