Windsor and Maidenhead · England
Cookham External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Cookham and across Windsor and Maidenhead. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Rain getting behind render or cladding at a joint
- Movement joints with cracked, split or missing sealant
- Sealant pulling away from one side of the joint
External mastic in Cookham
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, and when it fails, the wall takes the strain and water finds a way in. Common call-outs are for joints with sealant missing in places and leaking joints around cladding and façade panels, across joints between brick and frames, façade panels and render & cladding joints.
Outbuildings, garages and conservatories around homes in places like Cookham add more joints to look after. Leaks normally start at a gutter end, a garage door frame or where an extension meets the house.
You’re covered for a year from the day we finish. If anything isn’t right with it, call 0345 464 0079 or email us.
- Location
- Cookham (SL6)
- Region
- Windsor and Maidenhead
- Guarantee
- A year, on every job
- Quote
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Quotes for external mastic in Cookham
Some jobs are bigger than they look, and some smaller. What affects the quote:
- When we can work, for business premises
- How much old sealant there is and how hard it is to remove
- The size of the job
- Whether there’s mould to deal with
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
What we need to know
When you call or email, it’s useful to know:
- Photos by email, if that is easy
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
We do not publish a price list, because every job is different. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or email us.
What we’re called out for in Cookham
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
People normally contact us after spotting one of these:
- Weeds or debris growing in open joints
- Cracked joints where brick meets render or frames
- Failed sealant between panels on a façade
- Old sealant gone brittle and cracked
Rented homes near Cookham station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
What your quote should include
- When the joint can take water or movement
- Which sealant they’ll use, and why
- Whether they seal over old material or remove it
- Whether you can choose the colour
Walls and rooflines in Cookham
Historic houses like Cliveden (about 1.7 miles east) are a reminder that the area around Cookham has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Managing a site like Cookham Rise Primary School? Then its movement joints, gutters and trims need looking after like any other building’s. In the older streets around Church of St John the Baptist, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Cookham is about 2 miles south-east of Marlow, in Windsor and Maidenhead. Cookham gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Cookham is one of 57 places in Windsor and Maidenhead we cover. You can also see our page for Reading, about 13 miles away.
Jobs for external mastic in SL6 works the same way as everywhere else we cover. You’ll find streets such as Station Road, Church Road and High Street, and we cover them all. Other places close to Cookham include Cookham Dean (1 mile west), Furze Platt (2 miles south), Coldmoorholme (2 miles north), Bourne End (2 miles north-east) and Cores End (2 miles north-east). Larger places within reach include Windsor (7 miles south-east), Boyn Hill (3 miles south), North Ascot (10 miles south), Dedworth (7 miles south-east), Broomhall (12 miles south) and South Ascot (11 miles south). Cookham is one of the larger places we cover in Windsor and Maidenhead.
Landmarks near Cookham
We work in homes and buildings around The Old Swan Uppers pub and Furze Platt Senior School, among other places. There’s a railway station in Cookham itself: Cookham station. Nearby you’ll also find Marlow Museum (2.2 miles west) and Marlow Community Hospital (2.1 miles north-west). Open spaces near Cookham include Warren Nature Reserve and Taplow Lake.
The process
A visit follows a simple pattern: we look at the joints together, protect the area around them, carry out the job and tidy away. It usually takes anything from a few hours to several days, depending on the building. For a job in Cookham, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Preparing for the visit
- Move anything stored near the joints
- Tell us about any water getting in
- For business premises, tell us about site rules or sign-in
Getting a quote
Call for a quick quote, or email us if that is easier. Describe what needs sealing and we will explain what’s involved.
Read more
FAQs for Cookham
Is Cookham within the area you cover?
Yes. Cookham is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do you cover Cookham for external mastic?
Yes. We work across London and the South East, and Cookham is part of that. Just call 0345 464 0079 or send us an email with a few details of the job.
Is it OK to fill a movement joint with cement?
No. Mortar locks the joint solid, so the movement cracks the wall elsewhere. It needs a flexible sealant over backing rod.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
Are you fully insured?
Yes. Mr Mastic is fully insured, and we’ve been doing sealant work for more than 20 years.
Will you leave a mess?
We keep the work tidy. Nearby surfaces are protected, and we clear up when we’re done.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you do not need to watch us work.
Landlord and commercial work in Cookham
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
Towns and villages near Cookham
Also in Cookham
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
Leave it or put it right?
An open joint keeps letting water into the wall with every downpour. In cold weather, frost can damage wet brick and render around the joint, so the damage spreads beyond the joint. In an older home around Cookham, damp from a failed joint can get into timber and plaster, and that is a much bigger job than renewing the sealant.
No two jobs are quite the same, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all play a part, and we will explain the quote if you ask.
Why book with us
- Every job guaranteed for a year
- 180+ five-star Google reviews
- Any old sealant cut out fully, not covered over
- Sealant colour chosen to suit
See what affects the cost or our reviews.
Honest limits
We’d rather tell you now than do work that won’t last, so these are the limits:
- Cracks in the bricks or render themselves, away from the joints
- Loose or hollow render, which needs re-rendering
- Movement that’s more than a sealant joint can take
If you are not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer.
Joints and surfaces we work on
- Render & cladding joints
- Joints between brick and frames
- Façade panels
- Brickwork movement joints
- Copings & trims
- Concrete & block