Buckinghamshire · England
Gawcott External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Gawcott. Fully insured, ARBOMaster approved and guaranteed for a year.
- Joints pointed up with cement by mistake
- Sealant that has lost its bond to the brick or render
- Plants rooting in failed movement joints
External mastic in Gawcott, done properly
Short cuts in external joints show up within a season or two. New sealant over old, joints packed with mortar and beads with no backing rarely last long. We take the old material out and do it properly. We work on copings & trims, joints between brick and frames and concrete & block, and the jobs we see most are joints with sealant missing in places and damp patches traced to an open external joint.
Outside joints can only be sealed when they’re dry, so work in Gawcott is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
There’s a 12-month guarantee on every job, large or small.
- Place
- Gawcott (MK18)
- Wider area
- Buckinghamshire
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Work for landlords, hotels and businesses
If you manage several properties in or around Gawcott, several properties can go on one quote. Send us the addresses and the work at each, and pictures by email help.
We also work for property managers and facilities teams in Gawcott and across Buckinghamshire. Several sites can go on one quote, and we are fully insured for the work.
How the visit works
Before we leave, we go over the finished joints with you and tell you how long to leave it. The visit itself normally takes anything from a few hours to several days, depending on the building, depending on the size of the job. In a small place like Gawcott, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Clear the area around the work
- For indoor joints, keep the area dry beforehand if you can
- Mention any leaks or damp you’ve noticed
Getting a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll explain what’s involved and give you a clear price.
Related advice
Gawcott buildings and the weather
Historic houses like Stowe House (about 3.5 miles north) are a reminder that the area around Gawcott 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. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you live in an older home near Church of Holy Trinity, old and new materials meet at the roofline and walls, which is where sealant earns its keep. For site and facilities teams at buildings such as Roundwood Primary School, its movement joints, gutters and trims need looking after like any other building’s.
Gawcott is about 2 miles south-west of Buckingham, in Buckinghamshire. Across the MK18 area, we can carry out external mastic at your property. Gawcott is one of 263 places in Buckinghamshire we cover. You can also see our page for Oxford, about 18 miles away.
Every address in MK18 is covered for external mastic. That includes homes and businesses on Main Street, The Terrace and Oak Drive. Nearby, we also carry out external mastic in Tingewick (1 mile north-west), Preston Bissett (2 miles south-west), Hillesden (2 miles south), Finmere (3 miles west) and Twyford (4 miles south). Larger places within reach include Aylesbury (14 miles south-east), Elmhurst (14 miles south-east), Southcourt (15 miles south-east), Haydon Hill (13 miles south-east), Turnfurlong (15 miles south-east) and Haddenham (15 miles south).
Around Gawcott
We work in homes and buildings around Royal Latin School and The Cuckoo's Nest pub and the streets around them. Nearby you’ll also find Buckingham Movie Museum (1.7 miles north-east) and Buckingham Castle (1.5 miles north-east). For a walk, there’s Buckingham Sand Pit.
Honest limits
Honest advice matters more to us than a booking, so here’s what new sealant will not do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Render that is blown, hollow or coming away
- Cracking across the wall rather than at a joint
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Render & cladding joints
- Copings & trims
- Façade panels
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block
Surface by surface
Copings and trims
A failed coping joint lets water into the top of the wall. Resealing them is a small job that protects a lot.
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant in a colour to suit the brick.
Aftercare tips
Aftercare is simple:
- Never let anyone fill a movement joint with mortar
- Fix overflowing gutters above sealed joints
- Keep high-pressure jets off the joints
- Have failed joints looked at early
Don’t paint over the new sealant unless we’ve said the product is paintable. Many exterior sealants are not designed to be painted, and paint can crack as the joint moves.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established so early resealing is worth it.
Should I try it myself first?
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Nearby places to Gawcott
Other services in Gawcott
Why deal with it now?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. A stiffer product can damage the joint edge as it fails. Where a wall is exposed, as many are in small places like Gawcott, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Some things make a job bigger or smaller: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
What you get with us
- Full insurance on every job
- Domestic, commercial and hotel work
- 4.9 on Google from 180+ five-star reviews
- Arbo and Everbuild products
Read our cost guide or what customers say.
Common questions in Gawcott
Is Gawcott within the area you cover?
Yes. Gawcott 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.
Is Gawcott in your area for external mastic?
Yes, Gawcott is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job.
Can I add another job to the visit?
Yes, we can. Several rooms, windows or areas can go on one quote.
Why is there a gap in my brick wall?
Brickwork, render and cladding all move a little, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
Can you seal joints between render and window frames?
Yes. Where different materials meet is one of the most common joints we seal. The sealant is chosen to bond to both sides.
What colours does the sealant come in?
We aim for a joint that suits the wall rather than one that jumps out. Colour is agreed with you before we begin from the range available.
Should I try DIY first?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.
Do you take out the old sealant first?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.