Expansion and movement joint sealing
Movement and expansion joints in brickwork, precast and cladding, car park decks and floors stripped and resealed using a product matched to the movement each joint has to take.
- Sealant split down the centre of a wide joint
- Joints that have peeled away from one side
- Grit, weeds or debris packed into open joints
Expansion and movement joint sealing: send details for a fixed quote
Send drawings, photos or a joint schedule, or tell us about the site, and we’ll come back with a fixed quote.
What expansion and movement joint sealing covers
Buildings move. Temperature changes, moisture, shrinkage of new concrete and loading all open and close the joints designed into walls, slabs and panels. A movement joint only works while the sealant in it can stretch and compress without tearing or letting go. Once it fails, water, grit and debris get in, joint edges start to break down, and leaks follow, often some way from the joint itself. We reseal movement joints in brick and block walls, precast and cladding panel facades, podiums, car park decks and ramps, and internal floors. The work starts with finding out why the old seal failed: whether the gap is wider than the sealant can cope with, whether the bead was too thin, or whether it was stuck to the base of the gap. Then we choose a product with a suitable movement capability and rebuild the joint properly.
We work across South East England, Greater London and all of Scotland. Our workmanship carries a 12-month guarantee, we’re CHAS accredited and a Constructionline member, and our applicators hold CSCS cards.
Problems we put right
- Sealant split down the centre of a wide joint
- Joints that have peeled away from one side
- Grit, weeds or debris packed into open joints
- Water tracking through joints into the structure or rooms below
- Joint edges breaking up under traffic
- Old mastic that has hardened and stopped moving
Joints and areas we seal
- Brickwork movement joints
- Blockwork control joints
- Precast concrete panel joints
- Cladding panel joints
- Car park decks and ramps
- Podiums and floor movement joints
At a glance
- Fixed quote, scope in writing
- CSCS-carded applicators
- CHAS accredited · Constructionline member
- £5m public liability insurance
- 12-month guarantee
How it works
- We inspect the joints, measure widths and note how the old sealant has failed.
- The old sealant and any degraded backing are cut out completely.
- Joint faces are cleaned back to sound, dry material and primed where the sealant manufacturer specifies it.
- Closed-cell backing rod is set to depth, or bond-breaker tape in shallow joints, so the sealant grips the two faces and nothing behind.
- Sealant of a suitable movement class is applied and tooled firmly onto both faces.
- Records of the work are kept, and we flag any joint edges that need repair.
Width, depth and the two-sided rule
The width of a movement joint must suit the movement expected and the sealant’s movement capability. Depth matters just as much: an overly deep bead resists flexing, and one that is too thin tears. For wider joints the width-to-depth ratio is often around 2:1, as the manufacturer advises. Backing rod controls that depth and keeps the sealant off the joint base, because three-sided adhesion is one of the commonest causes of early splitting.
Car park decks and ramps
Joints in car park decks and ramps take tyre loads, turning wheels and de-icing salts, and the water they let through can reach the structure below. They need a sealant suited to trafficked joints, often a polyurethane, and careful preparation of the edges. Where arrises have already spalled, we’ll tell you if the edges need repairing before resealing, so the new sealant has something sound to grip.
Brick and panel facades
On brick and block walls, movement joints are often filled with old mastic that hardened years ago and no longer gives, so cracks appear in the masonry nearby. On precast and cladding panels, the joints are the main line of defence against rain. Low-modulus sealants are commonly used on these facades because they stretch easily and put less stress on the panel edges.
Why it’s worth doing now
A movement joint that has split or hardened can’t take the movement it was built for. The building moves anyway, so the stress goes into the brickwork, panels or slab instead, and water gets into the gap. Resealing in time protects the structure and avoids much bigger repairs.
What affects the quote
We don’t publish set prices, because no two buildings are the same. Send details and we’ll give you a fixed quote before we start. The main things that affect it are:
- How many metres of joint there are, and how many areas, elevations or sites
- How much failed sealant has to come out, and how hard it is
- Joint size, depth and whether backing rod or primer is needed
- Access: height, scaffold or MEWP access arranged by others, occupied areas
- The product the joint needs (and colour, where it matters)
- Programme, phasing and site requirements such as permits and inductions
What a good quote includes
- All failed sealant removed, never sealed over
- The product named for each joint type
- What the 12-month guarantee covers
- When each area can be used again
- Who is doing the work, their CSCS cards and the insurance in place
- What site paperwork and records are included
Aftercare
Walk the elevations and car park decks once a year, and look closely at joints after very hot or very cold spells. Keep joints clear of debris, vegetation and stored materials, and avoid pressure-washing directly into the sealant.
Trusted. Accredited. Insured.
Expansion and movement joint sealing: common questions
Is an expansion joint the same as a movement joint?
The terms are often used interchangeably. Both are gaps built in so sections of a structure can shift without cracking; expansion joints are one kind of movement joint.
Is it OK to seal on top of the failed bead?
No. Fresh sealant won’t bond reliably to old sealant, so we remove the failed material and clean the faces back first.
Why does backing rod matter?
It controls how deep the bead sits and gives the sealant nothing to grip at the base, so it flexes between the two faces as designed.
Can car park joints be done while the car park stays open?
Usually in phases. Tell us your site hours and access windows and we’ll plan bays or levels so the rest stays in use.
Will cold weather stop the work?
It can. Sealant needs a dry joint and temperatures within the product’s range, so damp or frosty mornings may delay external work.
Do you give a fixed price before you start?
Yes. Send photos, drawings or a joint schedule, or we can visit, and we’ll give you a fixed quote with the scope in writing before any work starts.
Are you accredited and insured?
Yes. We’re CHAS accredited and a Constructionline member, our applicators hold CSCS cards, and we carry £5m public liability insurance.
Page updated 3 November 2026
Near you
Find expansion and movement joint sealing in your town:
- London
- Glasgow
- Edinburgh
- Aberdeen
- Dundee
- Southampton
- Portsmouth
- Brighton
- Reading
- Oxford
- Guildford
- Chelmsford
- Maidstone
- Milton Keynes
- Watford
- Basildon
Advice
- Why Expansion Joints Fail and How to Fix Them
- Car Park Expansion Joints: Sealing and Upkeep
- Sealant Joint Design: Width, Depth and Backing
- Backing Rod Explained: Why It Matters
- Sealing Precast Concrete and Cladding Joints