Concrete repairs
Cracks, spalling, worn joints and pitted patches do not stay hidden once a new floor goes over them. They come back through the surface, telegraph through a coating and become the weak points where a floor starts to fail. Repairing the concrete first is what turns a tired, damaged slab into a sound base, whether the floor is being coated with resin or simply made good in its own right.
Surface Specialists arranges concrete repairs as part of preparing a floor and as standalone work. We match your project to the right repair and arrange the work by experienced specialist contractors, so the slab is sound before anything is laid over it. From survey onwards you deal with one specialist contractor. This page explains what concrete repairs cover, the common problems and how each is put right.
What are concrete repairs?
Concrete repairs are the work done to make a damaged or worn concrete floor sound again: filling and stabilising cracks, rebuilding spalled and pitted areas, repairing failed joints and reinstating a flat, solid surface. The aim is a sound, serviceable slab ready either to take a new floor finish or to carry on in service as repaired concrete. Repairs of this kind restore the surface and the joints; they do not add structural capacity, so a slab with a suspected structural problem needs an engineer’s assessment first.
On most projects, concrete repair is part of preparing a floor before a resin system goes on, because a coating is only as good as the slab beneath it. Repairs are also carried out as standalone work where a floor is breaking up, dusting or becoming a trip hazard and needs putting right. Either way the principle is the same: deal with the damage properly rather than coat over it and hope.
Common concrete floor problems
Most damage falls into a few recognisable types, each with its own cause and its own repair.
Cracks
Cracks range from fine surface crazing, which is usually cosmetic, to cracks that run through the slab and move under load. They are repaired according to whether the crack is dormant or still moving, because a dormant crack can be bonded back together while a moving one has to be given somewhere to move. Cracking that points to a structural problem with the slab is a matter for a structural engineer rather than a repair mortar.
Spalling and pitting
Spalling is where the surface breaks up and flakes away, leaving rough, pitted concrete, often from frost, impact, corrosion or a weak surface. The damaged area is cut back to sound concrete and rebuilt with a repair mortar to a flush, hard-wearing finish.
Failed joints
Movement and construction joints take a hammering from traffic and break down at the edges, or arris, leaving ragged, spalled joint lines. These are repaired and, where needed, fitted with the right joint detail so they stand up to continued trafficking.
Curling, delamination and weak surfaces
Curling at joint edges, a delaminated surface layer and weak, dusting concrete all leave a slab that will not carry a coating. The affected areas are ground back or cut out, made good and brought back to a sound, even surface ready for what goes on top.
How are concrete floors repaired?
The method is matched to the damage rather than a single fix applied to everything.
- Crack injection. Dormant cracks are injected with a rigid epoxy to bond the two sides back together, so the crack is held rather than just covered. A crack that is still moving is not injected rigidly, because it would re-crack alongside the repair. Depending on how much movement there is, it is either converted to an induced joint and sealed with a flexible filler or injected with a flexible polyurethane.
- Patch and mortar repair. Spalled, pitted and broken areas are cut back to sound concrete and rebuilt with a repair mortar to a flush, durable finish.
- Joint repair. Broken joint edges are reinstated and detailed so they take traffic without breaking down again.
- Resurfacing. Where the surface is generally worn or pitted rather than locally damaged, a resurfacing layer restores a sound, even finish across the floor. It relies on the base being strong enough to hold it and on the right preparation and bond coat. Any crack left untreated underneath will work its way back through.
The right combination is confirmed at survey, so the repair suits the slab and what is going on it rather than being more or less than the floor needs.
Where concrete repairs are needed
Damaged concrete turns up wherever a floor works hard and the repair is specified for the demands of the space. Common settings include:
- Warehouses and distribution centres. Forklift routes, turning areas and racking lines where joints and surfaces break down under constant traffic.
- Factories and workshops. Floors taking impact, point loads and spills that crack, spall and pit over time.
- Loading bays and ramps. Heavily trafficked edges and slopes where joints and arrises take the most punishment.
- Older and refurbished buildings. Tired slabs that are dusting, cracking or breaking up and need making sound before a new floor goes on.
Why repair concrete before coating?
A resin floor or coating bonds to the slab and follows its shape, so any damage left in the concrete becomes a flaw in the finished floor. A live crack reopens through the coating, a spalled patch shows as a weak, uneven spot and a broken joint keeps moving and breaks the surface above it. Very little of this can be cured by the coating on top. Crack-bridging systems do exist and have their place, but they are specified deliberately for known movement rather than used to cover damage, so the concrete is dealt with first.
Repairing the slab before coating is what gives the finished floor a sound base to bond to and it is one of the main reasons a floor lasts rather than failing along the lines of the damage that was painted over. Movement joints are the exception: they are carried through the finished floor rather than coated across, because a resin floor laid continuously over a moving joint will crack along it. It is the same principle that runs through all good floor preparation: the better the base, the better the chance the finish lasts.
What to know before you repair a floor
Find the cause. A repair only lasts if the cause is understood, so a moving crack or a corroding fixing is treated differently from simple wear. The damage is assessed at survey rather than just filled.
Repairs sit within preparation. On a floor being recoated, repairs are one step alongside grinding, screeding and, where moisture is an issue, an epoxy DPM. See our subfloor preparation services.
Downtime is planned. Repairs can usually be phased and fast-setting materials used where a floor has to come back into service quickly, so the work fits around how the floor is used.
Why choose Surface Specialists?
A repaired floor is only as good as the diagnosis behind it and the materials used and the result comes down to matching the right repair to the damage. That is what we arrange, matching the project to a specialist contractor who looks after it from start to finish.
- A specialist focus. We concentrate on resin and surface treatment, so the repair is specified for the slab and what is going on it rather than a one-size-fits-all answer.
- Experienced contractors. Repairs are carried out by established specialist contractors with the right materials for crack injection, patching and joint work.
- A sound base. The damage is diagnosed and put right so the floor has the best chance of lasting, whether it is recoated or left as repaired concrete.
- One point of contact. From survey through to a repaired, prepared floor, you deal with one specialist contractor.
Concrete repairs sit within our subfloor preparation work and underpin our commercial and industrial resin flooring. Learn more about Surface Specialists or explore the full range of resin flooring we cover.
Areas we cover
We arrange concrete repairs through experienced specialist contractors and are steadily extending the areas we cover. See our areas we cover hub for local detail, including resin flooring in Manchester with more local pages being added.
Get a quote
Tell us about your floor and the damage and we will arrange a free site survey and the contractor provides a written specification and quotation, typically within 48 hours. There is no obligation. Contact us to get started.
GET A FREE SITE SURVEY & QUOTATION
Frequently asked questions
What do concrete repairs cover?
Concrete repairs cover making a damaged floor sound again: filling and stabilising cracks, rebuilding spalled and pitted areas with a repair mortar, repairing failed joints and reinstating a flat, solid surface. They are done both to prepare a floor for a new finish and as standalone work on a slab that is breaking up.
How do you fix cracks in a concrete floor?
It depends on whether the crack is still moving. A dormant crack is cleaned out and either filled and sealed or, where it runs through the slab, injected with a rigid epoxy to bond the two sides back together. A live crack is not injected rigidly, because it would re-crack alongside the repair; it is converted to an induced joint or injected with a flexible polyurethane so the movement is accommodated rather than resisted. The crack is assessed first, because treating a moving crack as a static one just lets it return through the floor above.
What is spalling and can it be repaired?
Spalling is where the concrete surface breaks up and flakes away, leaving rough, pitted areas. It is repaired by cutting back to sound concrete and rebuilding with a repair mortar to a flush, hard-wearing finish. Treating the cause, such as frost or corrosion, is part of making the repair last.
Can you repair joints in an industrial floor?
Yes. Movement and construction joints that have spalled or broken at the edges are repaired and detailed so they take traffic again. Sound joints are essential on a trafficked floor, because a broken joint quickly damages the surface around it.
Can concrete repairs be done before a resin floor?
Yes and they usually are. Repairs are a standard part of preparing a slab for a coating, carried out alongside grinding, screeding and damp-proofing, so the resin floor goes on a sound base rather than over damage that would come back through it. Movement joints are the exception and are carried through the finished floor rather than coated across.
Which areas do you cover?
We work through a network of experienced specialist contractors and are extending the areas we cover. Contact us to confirm cover for your project.