Surrey · England
Window Mastic in Knaphill
Mastic around window and door frames, sills and patio doors for Knaphill, backed by a one-year guarantee. Call for a quick quote.
- Damp patches on the reveal after heavy rain
- Gaps between the frame and the inside reveal
- Untidy mastic left by window fitters
Common questions in Knaphill
I let a flat near Brookwood station. Can you help?
Yes. We work for landlords and letting agents as well as householders, and several properties can be quoted together. You can ring 0345 464 0079 or email us with the details for a clear quote.
Is Knaphill within the area you cover?
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.
Is there any odour?
Some sealants have a smell while they cure. Ventilation helps.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
Can I add another job to the visit?
Yes. Just list everything you need and we’ll quote it together.
Can you do the inside joint as well?
Yes. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Is it worth trying it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
Can new window sealant be painted?
It depends on the sealant. Some hybrid sealants can be painted; silicone cannot. Mention any painting plans before work begins.
About our window mastic in Knaphill
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. Where the air is getting in through the window itself, we will say so. We are often asked to deal with cracked internal joints between frame and plaster and water coming in at the bottom corners of a door, on aluminium frames, patio & French doors and timber windows & doors.
In a smaller place like Knaphill, some walls face open ground and catch the full force of the weather, so exposed windows and doors face the weather head on. That’s hard on the mastic around frames and sills.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Place
- Knaphill (GU21, GU24)
- Wider area
- Surrey
- Cover
- One year on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Looking after it afterwards
So the new joints stay in good condition:
- Keep jet washers away from the mastic
- Don’t paint over the silicone
- Clear any debris from frame drain holes
- Avoid harsh chemicals near the mastic
Check the drainage slots in the frames aren’t blocked, so rain drains out rather than building up at the sealant.
Signs to watch for: split or missing mastic, gaps, damp patches inside or black mould on the reveal. If you notice one, it’s time to get the joint looked at.
How the visit works
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours for a handful of frames, longer for a whole house. In a smaller place like Knaphill, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away, along with any loose debris.
- 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.
- The joint is shaped to shed water and the area tidied.
Getting ready for the visit
- Let us know about parking restrictions
- Where the joints are inside, avoid wetting them before we arrive
- Move anything stored near the joints
Get a quote
For window mastic in Knaphill, phone 0345 464 0079 or send us an email. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
Related advice
Knaphill homes and the weather
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
In the older streets around St Hugh of Lincoln's Church, the joint between an old wall and a newer frame is usually the first place rain gets in. For site and facilities teams at buildings such as Knaphill School, its window and door frames need their mastic kept sound, just like a home’s. Letting a property close to Brookwood station? Then cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Knaphill is about 2 miles west of Woking, in Surrey. Across the GU21 area, our applicators can take on window mastic. Our area takes in 395 places across Surrey, from the larger towns to small villages. You can also see our page for Reading, about 18 miles away.
Work in GU21 and GU24 works the same way as everywhere else we cover. Streets in the area include Wood Lane, High Street and Barnby Road, and we cover them all. We also cover Bisley (1 mile north-west), Sheet's Heath (1 mile south-west), Castle Green (1 mile north), Brookwood (1 mile south-west) and Penny Pot (1 mile north). We also work in nearby towns such as Guildford (5 miles south), Camberley (5 miles west), Epsom (15 miles east), Farnham (11 miles south-west), Egham (8 miles north) and Walton-on-Thames (10 miles north-east).
Around Knaphill
Around Knaphill, our work takes us to homes and buildings near Anchor Inn, The Winston Churchill School A Specialist Sports College and Brookwood Lye. The closest station to Knaphill is Brookwood station, roughly 1.4 miles south-west of the centre. A little further out are The Peacocks (2.5 miles east) and Brookwood Hospital (less than half a mile south). Green spaces nearby include Brookwood Lye.
What the job involves on each surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A tidy bead in anthracite grey, black or a matching colour suits the frame.
Timber windows & doors
Older timber windows in stone or brick can suit sand mastic rather than modern sealant. We can talk through the options.
Towns and villages near Knaphill
More services for Knaphill
What affects the cost of window mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The old material and how stubborn it is
- When we can work, for business premises
- Mould in or behind the old joints
- How easy the joints are to reach
Doing several joints on one visit is generally more efficient than separate visits, so tell us about everything that needs sealing. You will get one clear quote for the whole job.
What to tell us for a quote
When you contact us, it’s useful to know:
- If it’s domestic, commercial or a hotel
- Photos by email, if that is easy
- The address or postcode of the job
- How many joints, rooms or windows are involved
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Why it’s worth doing now in Knaphill
Running fresh sealant over the old joint is tempting, but it won’t grip old, dirty sealant. It soon lifts and the leak carries on behind it. The old mastic has to come out. In an older home around Knaphill, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs. Ask us for a quote and we’ll explain what it covers.
Why Knaphill clients choose us
- Approved under the ARBOMaster scheme
- Domestic, commercial and hotel work
- Any old sealant cut out fully, not covered over
- White, clear, grey or coloured to suit, where the product allows
Take a look at how sealant jobs are priced and customer reviews.
What we cannot put right
To be straight with you, there are a few things sealant will not fix:
- Rotten timber, which needs a joiner first
- A sash or casement that will not close properly
- Condensation trapped between the panes
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Where we work in Knaphill
- Timber windows & doors
- Composite doors
- uPVC windows
- Patio & French doors
- Aluminium frames
- Window sills
Can I do it myself?
A DIY attempt does not rule out a professional job. We cut it out and start again.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.