Frequently Asked Questions

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What is concrete spalling and why does it happen?

Concrete spalling, often referred to as 'blown' concrete, occurs when the surface of the concrete cracks, breaks, or flakes off, exposing the aggregat...

Concrete Repair Structural Integrity Diagnosis & Testing

How do you repair a spalled concrete surface?

Repairing spalled concrete involves a strictly regulated process, typically governed by BS EN 1504 standards. First, the damaged concrete is broken ou...

Concrete Repair Standards Structural Integrity

What is carbonation in concrete?

Carbonation is a chemical process where carbon dioxide (CO2) from the atmosphere penetrates the concrete and reacts with calcium hydroxide to form cal...

Diagnosis & Testing Infrastructure Corrosion

What is the difference between structural and non-structural concrete repair?

Structural repair (BS EN 1504-3 Class R3 or R4) restores the load-bearing capacity of the concrete element. It uses high-strength materials and possib...

Concrete Repair Structural Integrity Maintenance

Why do you use polymer-modified mortars for repairs?

Polymer-modified mortars contain resins (such as acrylics or SBR) that significantly improve the performance of the cement. Unlike standard sand-and-c...

Concrete Repair Materials Maintenance

What is cathodic protection in concrete repair?

Cathodic protection (CP) is an electrochemical technique used to halt corrosion in reinforced concrete. It works by connecting the steel reinforcement...

Concrete Repair Infrastructure Corrosion

How deep should concrete cover be over rebar?

The 'cover depth' is critical for protecting steel rebar from carbonation and chloride attack. British Standards (BS 8500) typically recommend a minim...

Standards Construction Specialist Services

What is Chloride Attack in concrete?

Chloride attack occurs when chloride ions (from seawater, sea spray, or de-icing salts) penetrate the concrete cover and reach the steel reinforcement...

Diagnosis & Testing Infrastructure Corrosion

What is 'honeycombing' in concrete?

Honeycombing refers to areas of concrete where the mortar has failed to fill the spaces between coarse aggregates, leaving a coarse, stony surface wit...

Concrete Repair Structural Integrity Maintenance

What is BS EN 1504?

BS EN 1504 is the European and British Standard for 'Products and systems for the protection and repair of concrete structures.' It provides a compreh...

Concrete Repair Standards Quality Assurance

Can you repair concrete cracks without rebuilding?

Yes, most concrete cracks can be repaired without demolition using resin injection. For non-structural cracks causing leaks, we use flexible polyureth...

Concrete Repair Materials Crack Repair

What is the Pull-Off Test in concrete repair?

The Pull-Off Test is a Quality Assurance (QA) method used to measure the bond strength of a repair material or coating to the concrete substrate. A me...

Concrete Repair Materials Diagnosis & Testing

What is an anti-carbonation coating?

An anti-carbonation coating is a high-performance protective paint applied to concrete surfaces. It is designed to be permeable to water vapor (allowi...

Diagnosis & Testing Corrosion Concrete Repair

What is Alkali-Silica Reaction (ASR)?

Often called 'concrete cancer,' Alkali-Silica Reaction (ASR) is a chemical reaction between alkalis in the cement paste and reactive silica found in c...

Diagnosis & Testing Construction Specialist Services

How do you treat exposed rebar in damaged concrete?

Treating exposed rebar is the most critical step in concrete repair. First, we remove the concrete around the bar (often 15-20mm behind it) to ensure ...

Concrete Repair Maintenance Construction

What is a 'cold joint' in concrete?

A cold joint forms when a batch of concrete begins to set before the next batch is poured against it, preventing the two layers from intermixing. This...

Concrete Repair Joint Sealing Maintenance

Why is surface preparation important for concrete repair?

Surface preparation is the single most important factor in the longevity of a repair. If the substrate is dirty, smooth, or friable, the new repair mo...

Concrete Repair Surface Preparation Maintenance

What is 'laitance' and why remove it?

Laitance is a weak, milky layer of cement dust and fine aggregates that rises to the surface of over-wet concrete or during troweling. It has very poo...

Surface Preparation Construction Specialist Services

What is Flowable Micro-concrete?

Flowable micro-concrete is a specialized, high-strength repair material designed to be poured or pumped into formwork. It has high fluidity, allowing ...

Structural Integrity Construction Specialist Services

What is thermal shock in concrete?

Thermal shock occurs when concrete is exposed to rapid and extreme temperature changes (e.g., steam cleaning a cold floor or hot industrial spills). T...

Construction Specialist Services

What is BS 8102:2022?

BS 8102:2022 is the British Standard 'Code of practice for the protection of below ground structures against water ingress.' It categorizes waterproof...

Waterproofing Structural Integrity Standards

What is Type A waterproofing?

Type A waterproofing, often called 'Barrier Protection,' involves applying a waterproof material to the internal or external surfaces of the structure...

Waterproofing Protection Construction

What is Type B waterproofing?

Type B waterproofing is 'Structurally Integral Protection.' It relies on the design and materials of the structure itself to be water-resistant. This ...

Waterproofing Protection Construction

What is Type C waterproofing?

Type C waterproofing is 'Drained Protection.' Instead of trying to hold back massive hydrostatic pressure physically, it accepts that some water may p...

Waterproofing Protection Construction

What is 'tanking' a basement?

Tanking is a traditional term for applying a waterproof lining to a basement, effectively turning it into a watertight tank. It usually refers to Type...

Waterproofing Protection Construction

What is hydrostatic pressure?

Hydrostatic pressure is the pressure exerted by a fluid at equilibrium due to the force of gravity. In waterproofing terms, it is the weight of the gr...

Waterproofing Protection Construction

What is a Cavity Drain Membrane?

A Cavity Drain Membrane is a High-Density Polyethylene (HDPE) sheet with a studded profile. It is mechanically fixed to basement walls. The studs crea...

Waterproofing Protection Construction

Why do you need a sump and pump system?

In a Type C (Cavity Drain) system, the water collected behind the membrane must go somewhere. If gravity drainage (draining downhill to a sewer) isn't...

Waterproofing Materials Protection

What is a fillet seal?

A fillet seal is a wedge of high-strength waterproofing mortar formed at the junction where the wall meets the floor. This 90-degree internal angle is...

Waterproofing Protection Construction

What is positive vs negative side waterproofing?

Positive side waterproofing is applied to the side of the structure in direct contact with the water source (e.g., the outside of a basement wall befo...

Waterproofing Protection Construction

What is a waterstop or waterbar?

A waterstop (or waterbar) is a pre-formed strip embedded into concrete joints (construction or expansion joints) to act as a physical barrier to water...

Waterproofing Joint Sealing Protection

What is an injection hose system?

An injection hose is a perforated tube installed in concrete construction joints before the concrete is poured. If a leak occurs later, resin can be i...

Waterproofing Joint Sealing Protection

What is a gas membrane?

A gas membrane is a specialized barrier designed to prevent the ingress of harmful ground gases like Radon, Methane, and Carbon Dioxide, as well as mo...

Waterproofing Protection Construction

What is the difference between damp proofing and waterproofing?

Damp proofing generally refers to resisting ground moisture (dampness) that is not under pressure, such as rising damp in walls above ground. Waterpro...

Waterproofing Protection Construction

How do you waterproof a lift pit?

Lift pits are notoriously prone to leaks as they are the lowest point of a building, often sitting in the water table. Because they endure high vibrat...

Waterproofing Protection Construction

Can you waterproof a brick basement?

Yes, but brick is more porous and flexible than concrete, making it harder to seal. Type A (Tanking) can be used, but it requires the removal of all p...

Waterproofing Protection Construction

What is a 'Grade 3' basement environment?

Defined by BS 8102, a Grade 3 environment is a 'dry environment' with no water ingress and humidity control, suitable for residential living, offices,...

Waterproofing Standards Basements

What is 'combined protection' in waterproofing?

Combined protection involves using two or more types of waterproofing (Type A, B, or C) on a single structure. For example, building a basement with w...

Waterproofing Protection Construction

What causes damp patches on internal walls?

Damp patches are usually caused by one of three things: penetrating damp (water coming through the wall from outside defects), rising damp (groundwate...

Waterproofing Protection Construction

How long does structural waterproofing last?

The lifespan of waterproofing depends on the system. Cementitious tanking and waterproof concrete can last the lifetime of the structure if not subjec...

Waterproofing Structural Integrity Protection

What is Polyurethane (PU) resin injection?

Polyurethane (PU) resin injection is the primary method for stopping water leaks in concrete. PU resins are hydrophobic and react with water. When inj...

Waterproofing Materials Crack Repair

What is the difference between PU and Epoxy injection?

The main difference is purpose: PU (Polyurethane) is for *waterproofing*, while Epoxy is for *structural repair*. PU is flexible and expands to stop l...

Waterproofing Structural Integrity Materials

What are injection packers?

Injection packers are mechanical valves inserted into holes drilled at 45-degree angles to a crack. They provide a secure connection for the high-pres...

Materials Crack Repair Waterproofing

What is curtain injection?

Curtain injection is a technique used to waterproof a structure from the *outside* without excavation. We drill a grid of holes through the wall and i...

Waterproofing Protection Construction

What is a thixotropic resin?

A thixotropic resin is a material that is thick (viscous) at rest but becomes fluid when agitated or pumped. This property is crucial for overhead inj...

Concrete Repair Materials Crack Repair

How do you repair a leaking diaphragm wall?

Diaphragm walls (D-walls) often leak at the vertical joints between panels. Repairing them requires deep injection using long packers to reach the cen...

Waterproofing Protection Construction

What is crack bridging?

Crack bridging refers to the ability of a coating or resin to span across a crack and remain intact even if the crack widens or moves due to thermal e...

Concrete Repair Maintenance Construction

What is low viscosity resin?

Low viscosity resin flows like water. This property allows it to penetrate hairline cracks as narrow as 0.05mm. High viscosity resins are like treacle...

Concrete Repair Materials Crack Repair

How does hydrophobic resin differ from hydrophilic?

Hydrophobic resins repel water and do not mix with it; they are typically used to form rigid or semi-rigid seals once water flow has been stopped. Hyd...

Materials Crack Repair Waterproofing

What is piling injection?

Piling injection involves forcing resin into voids or defects within deep concrete foundation piles. Piles can suffer from 'necking' (narrowing) or so...

Concrete Repair Maintenance Construction

What causes expansion joint failure?

Expansion joints fail due to the degradation of the sealant material (from UV or age), 'compression set' (where the sealant loses its ability to bounc...

Joint Sealing Construction Specialist Services

What is a Hypalon bandage system?

A Hypalon bandage (such as the Sikadur-Combiflex system) is a high-performance sealing strip used over expansion joints and large cracks. It consists ...

Joint Sealing Construction Specialist Services

What is a backer rod and why is it used?

A backer rod is a foam cylinder inserted into a joint before applying sealant. It serves two purposes: it controls the depth of the sealant (preventin...

Joint Sealing Construction Specialist Services

How do you repair a damaged joint arris?

The 'arris' is the sharp edge of a concrete joint. Heavy traffic often breaks these edges (spalling). To repair them, we saw-cut the concrete to creat...

Concrete Repair Joint Sealing Structural Integrity

What is an elastomeric coating?

An elastomeric coating is a paint-like system that forms a rubbery, flexible membrane when dry. It can stretch (elongate) by several hundred percent w...

Construction Specialist Services

What is the difference between silicone and polyurethane sealants?

Silicone sealants offer excellent UV resistance and temperature stability, making them ideal for glazing and exposed facades. However, they are genera...

Materials Joint Sealing Construction

What is Shore Hardness in sealants?

Shore Hardness measures the resistance of a material to indentation. For joint sealants, we typically look at Shore A. A low Shore A (e.g., 20) is sof...

Joint Sealing Construction Specialist Services

What is 'overbanding' in road repair?

Overbanding is a surface repair technique for sealing cracks in asphalt or concrete roads. A strip of hot-applied bituminous or resin-based material i...

Concrete Repair Flooring & Car Parks Maintenance

Why do car park expansion joints leak?

Car park expansion joints leak due to the extreme dynamic loads they suffer. Vehicles braking and accelerating over the joint exert shear forces that ...

Waterproofing Flooring & Car Parks Joint Sealing

What is movement joint in construction?

A movement joint is a designed break in a structure to allow for expansion, contraction, or settlement without causing uncontrolled cracking. They div...

Structural Integrity Joint Sealing Construction

What is PMMA resin flooring?

PMMA (Polymethyl Methacrylate) is a rapid-curing resin system used for high-performance flooring and deck coatings. Its key advantage is speed: it cur...

Materials Flooring & Car Parks Crack Repair

What is a 'wearing course' in a car park?

The wearing course is the topmost layer of a car park deck coating system. It is the sacrificial layer that takes the physical abuse of tyres, braking...

Flooring & Car Parks Maintenance Protection

Why is dynamic crack bridging important for car parks?

Car parks are flexible structures; they vibrate and move as cars drive over them. 'Dynamic' crack bridging means the deck coating can stretch and reco...

Concrete Repair Waterproofing Flooring & Car Parks

What is SRV (Slip Resistance Value)?

SRV (Slip Resistance Value), often measured using a Pendulum Test, quantifies the grip of a floor surface. For public areas and car parks, achieving a...

Materials Flooring & Car Parks Crack Repair

What is anti-skid surfacing?

Anti-skid (or high friction) surfacing involves applying a resin binder seeded with calcined bauxite aggregate. It provides exceptional grip and is co...

Flooring & Car Parks Safety Construction

How do you repair a pothole in a concrete deck?

Repairing a pothole in a concrete deck requires more than just filling it. We square cut the edges (to avoid feather edging), break out the loose mate...

Flooring & Car Parks Safety Construction

What is 'ramp heating'?

Ramp heating involves embedded electrical cables or fluid pipes within the car park ramp structure that heat up to prevent ice and snow accumulation. ...

Flooring & Car Parks Safety Construction

Why use rapid cure resins for car parks?

Closing a car park costs money and causes disruption. Rapid cure resins, particularly PMMA, cure fully in under an hour, allowing us to repair a ramp,...

Materials Flooring & Car Parks Crack Repair

What is Concrete Surface Profile (CSP)?

Concrete Surface Profile (CSP) is a standardized measure of surface roughness, ranging from CSP 1 (smooth) to CSP 9 (very rough). Different repair mat...

Surface Preparation Construction Specialist Services

What is grit blasting?

Grit blasting (or abrasive blasting) involves firing abrasive particles at high speed against a concrete surface. It is used to clean steel rebar of r...

Surface Preparation Construction Specialist Services

What is scabbling?

Scabbling is a mechanical process using a machine with multiple pounding pistons (scabblers) to chip away the concrete surface. It is more aggressive ...

Surface Preparation Construction Specialist Services

What is a cover meter?

A cover meter is an electromagnetic device used to locate steel reinforcement bars inside concrete without drilling. It tells us the location, orienta...

Diagnosis & Testing Construction Specialist Services

What is a Schmidt Hammer test?

A Schmidt Hammer (or Rebound Hammer) is a non-destructive testing tool used to estimate the compressive strength of concrete. It fires a spring-loaded...

Diagnosis & Testing Construction Specialist Services

What is the Phenolphthalein Test?

The Phenolphthalein Test is the standard method for determining the depth of carbonation in concrete. We spray a solution of phenolphthalein onto a fr...

Diagnosis & Testing Corrosion Concrete Repair

Why is moisture content important for coatings?

Most resin coatings (Epoxy, PU) are moisture-sensitive. If applied to damp concrete, they will bubble, blister, or delaminate. We measure the moisture...

Surface Preparation Diagnosis & Testing Construction

What is the 'Dew Point' in coating application?

The Dew Point is the temperature at which moisture condenses from the air onto a surface. If the substrate temperature is at or below the dew point, a...

Diagnosis & Testing Construction Specialist Services

What is a substrate in concrete repair?

The substrate is the underlying surface onto which a repair material, coating, or membrane is applied. In our work, this is usually the original concr...

Concrete Repair Surface Preparation Maintenance

What is a penetration seal?

A penetration seal is a system used to seal the gaps where services (pipes, cables, ducts) pass through fire-rated walls or floors. These gaps breach ...

Waterproofing Fire Safety Protection

What is an intumescent material?

Intumescent materials are substances that swell up significantly when exposed to heat. In fire stopping, they are used in sealants, collars, and wraps...

Materials Fire Safety Protection

What are fire batts?

Fire batts are high-density mineral wool boards coated with an ablative fire-resistant paint. They are used to seal large openings in walls or floors ...

Fire Safety Protection Safety

What is an ablative coating?

An ablative coating works by absorbing the energy of a fire. When heated, the coating undergoes a chemical reaction that consumes heat energy (endothe...

Fire Safety Protection Safety

What is compartmentation in fire safety?

Compartmentation is the subdivision of a building into smaller fire-resistant 'boxes' or compartments using fire-rated walls and floors. The goal is t...

Fire Safety Protection Safety

What is a fire collar?

A fire collar is a metal band containing an intumescent liner that is fitted around plastic pipes where they pass through a wall or floor. In a fire, ...

Fire Safety Protection Safety

What is a soffit in concrete construction?

The soffit is the underside of any construction element, such as a concrete slab, beam, or staircase. In concrete repair, soffits are critical areas b...

Construction Specialist Services

What is an upstand in waterproofing?

An upstand is a vertical section of a roof or floor slab that turns up against a wall or parapet. In waterproofing, the upstand is a critical detail. ...

Waterproofing Protection Construction

What is a 'kicker' in concrete?

A kicker is a small concrete step (usually 50-100mm high) cast at the base of a wall or column before the main pour. It allows the formwork for the wa...

Waterproofing Joint Sealing Protection

What is a chase in construction?

A chase is a groove or channel cut into masonry or concrete. In waterproofing, we often cut a chase at the wall-floor junction to install a repair mor...

Waterproofing Protection Construction

What is grout in structural repair?

In structural repair, grout refers to a highly fluid mixture of cement, sand, and water (often with polymers/resins) used to fill voids, seal cracks, ...

Structural Integrity Materials Construction

What is a screed?

A screed is a layer of material (usually sand and cement) applied over a structural concrete base to create a smooth, level surface for the final floo...

Flooring & Car Parks Safety Construction

What is structural integrity?

Structural integrity is the ability of a building or infrastructure to support its designed loads (weight, wind, traffic) without collapsing or deform...

Concrete Repair Structural Integrity Maintenance

What does load bearing mean?

A load-bearing element (wall, column, beam) supports the weight of the structure above it. Damaging a load-bearing element can lead to catastrophic co...

Structural Integrity Management Best Practice

What is a retrofit?

Retrofit involves adding new technology or features to an existing building. In our context, it often means retrofitting a waterproofing system to a b...

Structural Integrity Construction Specialist Services

What is infrastructure maintenance?

Infrastructure maintenance involves the repair and protection of essential public structures like bridges, tunnels, aqueducts, and retaining walls. Th...

Infrastructure Construction Specialist Services

What is 'feather-edging' and why avoid it?

Feather-edging is the practice of troweling a repair mortar out to a super-thin layer (a feather edge) to blend it with the surrounding surface. This ...

Concrete Repair Maintenance Construction

What is a 'Form and Pour' repair?

Form and pour is a technique used for large volume concrete repairs. Instead of hand-applying mortar in layers, we build a shutter (formwork) around t...

Concrete Repair Maintenance Construction

What is concrete resurfacing?

Concrete resurfacing involves removing the top deteriorated layer of a concrete slab (using planing or scabbling) and replacing it with a new, high-st...

Concrete Repair Maintenance Construction

What is passivation of steel?

Passivation is the formation of a protective oxide film on the surface of steel rebar, created by the high alkalinity of fresh concrete. This film pre...

Infrastructure Construction Specialist Services

What is a bonding bridge?

A bonding bridge (or bonding agent) is a slurry applied to the prepared existing concrete surface immediately before applying the new repair mortar. I...

Materials Infrastructure Construction

What are the CDM Regulations?

The Construction (Design and Management) Regulations 2015 (CDM) are the main set of regulations for managing the health, safety, and welfare of constr...

Standards Management Best Practice

Do you provide warranties for waterproofing?

Yes. Waterproofing is a critical protection for a building, and clients need peace of mind. MPS Concrete provides long-term warranties for our install...

Waterproofing Protection Construction

What is a Method Statement?

A Method Statement is a detailed document that describes exactly *how* a specific task will be carried out safely. It covers the equipment used, the s...

Construction Specialist Services

What is consultancy in concrete repair?

Consultancy involves providing expert advice *before* the physical work begins. MPS offers consultancy services to survey defects, diagnose causes (e....

Concrete Repair Diagnosis & Testing Maintenance

What is a Grade 2 basement environment?

A Grade 2 basement (BS 8102) requires 'no water penetration,' but some dampness is tolerable depending on the use (e.g., plant rooms, workshops, retai...

Waterproofing Standards Basements

What is 'blowhole' filling?

Blowholes are small, pinhead-sized voids on the surface of concrete caused by trapped air bubbles against the shuttering during casting. While structu...

Concrete Repair Maintenance Construction

What is 'breakout' in concrete repair?

Breakout is the mechanical removal of defective concrete. It is the noisy, dusty first step of repair. We use percussive breakers or hydro-demolition ...

Concrete Repair Materials Maintenance

What is a 'sacrificial anode'?

A sacrificial anode is a block of active metal (usually zinc) wired to the steel rebar within a concrete repair. Because zinc is more electrochemicall...

Infrastructure Construction Specialist Services

What is the 'halo effect' in concrete repair?

The halo effect (incipient anode formation) happens when a patch repair is done *without* treating the surrounding steel. The new patch is highly alka...

Concrete Repair Infrastructure Maintenance

What is shotcrete or gunite?

Shotcrete (or Gunite) is concrete sprayed at high velocity onto a surface using compressed air. It compacts itself upon impact. It is used for large-s...

Concrete Repair Maintenance Construction

What is a fairing coat?

A fairing coat is a thin layer (1-3mm) of polymer-modified mortar applied over a repaired concrete surface. Its purpose is aesthetic and protective: i...

Concrete Repair Maintenance Construction

What is 'pot life' in resin injection?

Pot life is the time you have to use a mixed resin before it starts to harden. In injection work, this is critical. A fast-reacting PU resin might hav...

Materials Crack Repair Waterproofing

What is a slab soffit?

A slab soffit is the underside (bottom face) of a concrete slab. In multi-storey buildings and car parks, the soffit is the ceiling surface you see wh...

Concrete Repair Structural Integrity Construction

What is concrete repair mortar?

Concrete repair mortar is a pre-blended, polymer-modified cementitious mix designed specifically for restoring damaged concrete. Unlike standard cemen...

Concrete Repair Materials Construction

What is a column kicker in construction?

A column kicker is a short concrete stub (typically 50–150 mm high) cast on top of a floor slab to mark the exact position and alignment of a column b...

Waterproofing Joint Sealing Construction

What is a wear course in a car park?

A wear course is the top layer of a car park deck surfacing system — the surface that tyres drive on. It sits above the waterproofing membrane and is ...

Flooring & Car Parks Materials Construction

How much more does self-healing concrete cost?

Self-healing concrete typically carries a cost premium of 10–15% over conventional concrete, depending on the self-healing mechanism used. Bacterial (...

Materials Innovation Construction

How does basement tanking work and what does it cost?

Basement tanking involves applying a continuous waterproof barrier to the internal or external faces of basement walls and floors. The most common met...

Waterproofing Protection Construction

What is void grouting in concrete?

Void grouting is the process of injecting cementitious grout, resin, or polyurethane foam into voids beneath or within concrete structures. Voids can ...

Concrete Repair Specialist Services Infrastructure

What is PMMA floor coating?

PMMA (polymethyl methacrylate) is a rapid-curing resin system used for waterproofing and surfacing car park decks, balconies, walkways, and industrial...

Flooring & Car Parks Materials Construction

How do you choose the right concrete repair mortar?

Choosing the right repair mortar depends on five factors: repair depth (thin-layer vs structural), orientation (horizontal, vertical, or overhead), lo...

Concrete Repair Materials Construction

What causes concrete to spall?

The most common cause of concrete spalling is reinforcement corrosion. As steel rebar rusts, it expands up to seven times its original volume, generat...

Concrete Repair Structural Integrity Diagnosis & Testing

What is BS 8102 and what are the waterproofing grades?

BS 8102:2022 is the UK code of practice for protection of below-ground structures against water from the ground. It defines three types of waterproofi...

Waterproofing Standards Construction

What is involved in concrete floor repair?

Concrete floor repair typically involves four steps: assessment (identifying the type and extent of damage using visual inspection, hammer testing, an...

Concrete Repair Flooring & Car Parks Construction

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