Hampshire · England
Test Valley Window Mastic
Mastic around window and door frames, sills and patio doors for Test Valley, backed by a 12-month guarantee. Call for a quick quote.
- Black, perished sealant on frames
- Cold air getting in at the frame edge
- Draughty joints inside around the window
How we handle window mastic in Test Valley
Every window and door frame has a gap around it, and mastic is what closes it. Once that seal fails, wind and rain find the gap. Our applicators cut it out and replace it with a flexible, weatherproof sealant. We are often asked to deal with cracked or shrunken mastic around the frame and leaking joints at the ends of sills, across patio & French doors, uPVC windows and timber windows & doors.
Outdoor sealant needs dry, clean surfaces, so work on frames around Test Valley is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
All of our work is guaranteed for twelve months.
- Location
- Test Valley (SP11)
- Region
- Hampshire
- Guarantee
- One year on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Surface by surface
Composite doors
Composite doors are normally hung in an uPVC-type frame, and the joint around it is sealed like a window. We match the colour to the frame.
uPVC windows
We clean the frame edge carefully so the plastic isn’t marked, then the new bead is laid against the frame and the wall.
How it works
Our applicators work methodically: protect, prepare, seal, tidy. For most jobs that takes a few hours for a few frames, or a day or more for a whole house and we leave things clean and tidy. Somewhere like Test Valley needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We start by checking each window and door with you.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- We clear up and check every joint is fully closed.
How to prepare
- Let us know about parking restrictions
- Let us know about earlier repairs to the joints
- Tell us about any water getting in
Ask for a quote
Every job is quoted individually. Simply call 0345 464 0079 or drop us an email and describe the job.
Advice
Places near Test Valley
Other services in Test Valley
Questions from Test Valley
Do you cover Test Valley for window mastic?
Yes, Test Valley is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or email us and tell us what needs doing, and we’ll give you a clear price.
Do you cover smaller places like Test Valley?
Yes. Test Valley is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
What does window mastic cost?
We don’t publish prices, because the cost depends on the job: its size, the old material, access and the product needed. You will get a clear quote before we start.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we’ll explain our choice.
Do you hold any approvals?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Is the new sealant paintable?
That depends on the product. Silicone isn’t paintable, but some hybrid sealants are. Mention any painting plans before we start.
Can you do upstairs windows?
Yes, where they can be reached safely. Let us know about access when you ask for a quote and we will plan for it.
Can you seal the gap between the frame and the plaster indoors?
Yes. Plenty of draughts come through the inside joint as well as the outside, so it can be worth sealing both.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Honest limits
We’d rather tell you now than do work that will not last, so here’s what sealant cannot put right:
- Damp problems in the wall away from the window
- A door that needs adjusting, rehanging or new seals
- Soft or decayed wood in the frame
If you are not sure, just call 0345 464 0079 or email us and we’ll give you a straight answer.
Surfaces we seal
- Composite doors
- Window sills
- Aluminium frames
- Patio & French doors
- Timber windows & doors
- uPVC windows
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Keep jet washers away from the mastic
- Keep timber frames painted
- Look round the frames every year or so
- Avoid harsh chemicals near the mastic
Clean the frames with mild soapy water, and avoid solvent cleaners on the sealant.
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.
Window mastic in Test Valley: local notes
Historic houses like Stargroves (about 2.7 miles north) are a reminder that the area around Test Valley has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you live in an older home near Church of St James, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Around Test Valley, as everywhere, window mastic is only as good as the preparation behind it.
Test Valley is about 7 miles north of Andover, in Hampshire. Anywhere in SP11, we can carry out window mastic at your property. Test Valley is one of 683 places in Hampshire we cover for window mastic. There’s also a page for Reading, about 22 miles away.
Every address in SP11 is within our area for window mastic, from the main roads to the quietest streets. Close by, we work in Ashmansworth (1 mile east), Vernham Street (3 miles west), Upper Green (4 miles north), Inkpen Common (5 miles north) and Hell Corner (5 miles north). Larger places within reach include Basingstoke (15 miles east), Andover (7 miles south), Tadley (13 miles east), Popley (15 miles east), Tidworth (11 miles south-west) and Kempshott (13 miles east).
Landmarks near Test Valley
For a walk, there’s Pilot Hill.
What affects the quote in Test Valley
Every job gets its own quote. These are the things that affect it:
- How many rooms, windows or areas are involved
- The number and length of the joints
- When we can work, for business premises
- How much old sealant there is and how hard it is to remove
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
What we need to know
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- Where the property is
- The rough size of the job
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.