Defect Atlas — Historic Concrete

A network of fine, interconnected surface cracks across a concrete face.

Polygonal or random pattern of fine cracks, sometimes more visible when the surface is damp or under raking light.

Plastic shrinkage, drying shrinkage, surface treatments and matrix-related processes can be associated.

• extent of the cracked area
• approximate crack width range where visible
• whether cracks appear confined to the surface or extend deeper
• any associated staining at the crack lines

“Map cracking was recorded across the south elevation panel, with a fine polygonal pattern most visible following light rainfall.”

Short, often parallel cracks that may have formed during early curing of the concrete.

Short, discontinuous cracks of broadly similar orientation, sometimes most visible on horizontal or formed surfaces.

Early-age moisture loss during placement and curing can be associated.

• orientation and spacing of cracks
• length of typical cracks
• any associated surface irregularities
• whether cracks coincide with placement features

“Cracking consistent with plastic shrinkage was recorded across the slab soffit, with short parallel cracks of broadly similar orientation.”

Cracks that may be associated with longer-term drying of the concrete.

Fine to moderate cracks, often broadly evenly spaced on long unrestrained elements, sometimes terminating at joints or openings.

Restraint to drying movement and original mix characteristics can be associated.

• spacing and length of cracks
• relationship to joints, openings or restraints
• whether cracks pass through the full thickness where visible
• any associated staining or efflorescence

“Cracking consistent with drying shrinkage was recorded along the parapet, with fine cracks at broadly regular spacing between movement joints.”

Cracks of pattern, location or width that may indicate structural action, where engineering assessment would be required.

Cracks following lines of stress — diagonal at supports, vertical at mid-span on the tension face, or stepped at openings — sometimes with measurable opening.

Loading, support conditions, movement of supporting structure and embedded fixings can be associated; visual observation alone is not sufficient to confirm cause.

• location, orientation and length of cracks
• approximate width and any taper along length
• presence of associated displacement or step
• whether cracks appear active where comparison is possible

“Cracking consistent with possible structural action was recorded at the support of the beam, with a diagonal crack extending approximately 450 mm and a width up to 1 mm at its widest point.”

A crack or opening at the line of an original construction joint between concrete pours.

Linear discontinuity following the joint line, sometimes with associated staining, efflorescence or water tracking.

Movement, original joint preparation and water penetration at the joint can be associated.

• location and length of joint affected
• approximate opening where visible
• evidence of water movement through the joint
• any associated displacement between pours

“Cracking was recorded at the horizontal construction joint of the wall, with an opening up to 0.5 mm and associated staining on the lower pour.”

Cracking or distress at or adjacent to a designed movement joint.

Cracks parallel to or radiating from a movement joint, sometimes with associated edge loss, debris or sealant failure.

Joint width, sealant condition and accommodated movement can be associated.

• location of distress relative to the joint
• condition of any sealant or filler
• presence of debris within the joint
• evidence of differential movement across the joint

“Cracking was recorded adjacent to the vertical movement joint, with edge loss to the concrete arris and failed sealant within the joint.”

Cracks radiating from or surrounding an embedded fixing, bolt, pipe or other item.

Cracks emerging from the perimeter of the embedded item, sometimes with associated staining or spalling.

Corrosion of the embedded item, loading at the fixing and inadequate cover can be associated.

• type and location of the embedded item
• extent and orientation of associated cracks
• presence of corrosion staining at the cracks
• whether the fixing remains secure where assessable

“Cracking was recorded around the embedded bracket fixing, with radial cracks extending approximately 60 mm and associated rust-coloured staining.”

Brown or orange staining on the concrete surface that may indicate corrosion of embedded reinforcement or fixings.

Rust-coloured stain on the concrete face, sometimes following the line of reinforcement, sometimes localised at a crack or spall.

Possible corrosion of embedded steel, ferrous fixings or earlier ferrous repair materials can be associated; confirmation requires investigation.

• extent, intensity and pattern of staining
• whether the stain follows the apparent line of reinforcement
• presence of associated cracking, spalling or efflorescence
• location relative to cover, joints and exposure

“Rust-coloured staining was recorded across the soffit, broadly following the apparent line of reinforcement at approximately 200 mm centres.”

Cracking that broadly follows the apparent line of embedded reinforcement.

Linear cracks of broadly regular spacing parallel to one or more directions, sometimes with associated staining or surface lift.

Possible expansion of corroding reinforcement and inadequate cover can be associated; confirmation requires cover survey and testing.

• orientation, spacing and length of cracks
• whether cracks coincide with rust-coloured staining
• presence of associated surface lift or spalling
• approximate cover at adjacent intact areas if measurable

“Cracking broadly following the apparent line of reinforcement was recorded across the parapet face, with associated rust-coloured staining at several crack lines.”

Loss of the concrete cover layer exposing or partially exposing embedded reinforcement.

Recessed area with exposed or partially exposed reinforcement, often with rust-coloured staining and detached fragments nearby.

Possible reinforcement corrosion, inadequate cover, freeze–thaw action and impact can be associated.

• size and depth of spalled area
• extent of reinforcement exposed
• apparent condition of the exposed steel
• presence of further spalls or detached fragments nearby

“Cover spalling was recorded on the underside of the canopy, with a loss approximately 250 by 120 mm exposing two reinforcement bars with visible corrosion product.”

Reinforcement bars visible at the concrete face with little or no remaining cover.

Bars visible at the surface, sometimes with corrosion product, sometimes with reduced section where measurable.

Original low cover, surface loss and earlier damage can be associated.

• length of bar exposed
• apparent diameter and condition of exposed steel
• presence and extent of corrosion product
• any apparent loss of section

“Exposed reinforcement was recorded at the lower edge of the panel, with approximately 300 mm of bar visible and surface corrosion product across its length.”

Hollow-sounding or visibly lifted concrete cover that may detach in due course.

Surface that sounds hollow on light tapping, sometimes with fine cracking around the perimeter, sometimes with associated staining.

Possible reinforcement corrosion or internal delamination can be associated.

• extent of hollow-sounding areas where light tapping is appropriate
• presence of perimeter cracking
• any associated rust-coloured staining
• location relative to overhead or publicly accessible areas

“Incipient spalling was recorded on the soffit, with an area approximately 400 by 300 mm sounding hollow on light tapping and showing fine perimeter cracking.”

Rust-coloured staining concentrated at a joint, crack or other discontinuity.

Stain emerging from a linear feature and washed across the surface, sometimes with associated efflorescence.

Possible water and chloride ingress to embedded steel at the discontinuity can be associated.

• location and extent of staining
• association with a specific joint, crack or feature
• presence of associated efflorescence or salt deposits
• exposure of the area to rainwater run-off

“Corrosion staining was recorded emerging from the horizontal construction joint, with a brown stain extending approximately 400 mm down the wall face.”

Loss of a discrete piece of the concrete surface leaving a recessed area.

Localised cavity with relatively fresh-looking exposed aggregate or matrix; sometimes with detached fragment nearby.

Frost action, impact, reinforcement corrosion and salt activity can be associated.

• size and depth of spalled area
• whether reinforcement is exposed at the spall
• presence of associated cracking
• any detached fragments retained nearby

“Surface spalling was recorded at the cill, with a loss approximately 120 mm across and 25 mm deep at the front arris.”

Loss of thin surface layers across an area, exposing the underlying matrix or aggregate.

Roughened, recessed surface with loss of the original finish; sometimes with detached scales nearby.

Freeze–thaw action, salt activity and weak surface zones can be associated.

• extent of scaled area
• approximate depth of loss
• comparison with sheltered or intact areas
• presence of associated cracking or salts

“Surface scaling was recorded across the horizontal coping, with loss of the original finish and exposure of the underlying matrix across approximately 0.5 m².”

Separation of a surface layer from the underlying concrete along an internal plane.

Hollow-sounding areas on light tapping, sometimes with visible lifting at edges, sometimes with stepped loss where layers have come away.

Possible reinforcement corrosion, weak surface zones, freeze–thaw action and earlier surface treatments can be associated.

• extent of delaminated area
• depth of separation where visible
• presence of associated cracking, staining or repairs
• location relative to embedded reinforcement where known

“Delamination was recorded on the rendered concrete face, with an area approximately 0.8 m² sounding hollow on light tapping and partial lifting at the lower edge.”

Loss of the cement-rich outer layer exposing aggregate beneath.

Roughened surface with exposed aggregate, loss of original tooling or formed finish; smoother in sheltered areas.

Long-term weathering, rainwater run-off and exposure orientation can be associated.

• extent of eroded surface relative to sheltered areas
• approximate depth of cement matrix lost
• loss of original surface treatment or finish
• comparison with adjacent more sheltered surfaces

“Erosion of the cement-rich surface was recorded across the exposed upper face, with aggregate now visible where original tooling marks survive in sheltered areas.”

Loss of material at the edges or arrises of concrete elements.

Rounded, broken or missing arrises; loss extending back from the original edge; sometimes with associated cracking.

Impact, frost action, water shedding and traffic can be associated.

• length of arris affected and approximate depth of loss
• exposure of the affected edge
• any associated cracking running from the edge
• evidence of repeated impact

“Edge and arris loss was recorded along the lower edge of the panel, with loss extending up to 30 mm back from the original arris over approximately 1.2 m.”

Localised surface loss around a fixing, bolt, pipe or other penetration through the concrete.

Recessed area around the penetration, sometimes with corrosion staining and detached fragments.

Possible corrosion of the embedded item, water ingress around the penetration and original detailing can be associated.

• size and depth of loss around the item
• condition of the fixing or penetration where assessable
• presence of associated staining and corrosion
• evidence of water tracking at the penetration

“Loss at the fixing was recorded around the embedded bolt, with a recessed area approximately 80 mm across and associated rust-coloured staining.”

Surface conditions that, alongside other evidence, may be associated with carbonation advance, where testing would be required for confirmation.

Reduced surface alkalinity is not directly visible; associated conditions may include line cracking, rust-coloured staining and cover spalling on otherwise dry, well-detailed elements.

Atmospheric exposure, original cover, mix porosity and surface protection history can be associated; confirmation requires phenolphthalein testing on freshly broken or drilled surfaces.

• elements and exposures where indicators are concentrated
• approximate age and exposure history of the element
• presence of associated reinforcement corrosion indicators
• areas suitable for sampling or test breakouts where appropriate

“Visual indicators that may be consistent with carbonation advance were recorded across the sheltered cover panel, with associated rust-coloured staining at the line of reinforcement; carbonation depth testing would be required for confirmation.”

Surface conditions that, alongside exposure history, may be associated with chloride ingress, where sampling and testing would be required for confirmation.

No directly visible feature is specific to chlorides; associated conditions may include intense localised corrosion staining, pitting at exposed reinforcement, and damage concentrated at splash zones, traffic surfaces or de-iced areas.

Possible exposure to de-icing salts, marine environments, retained chloride contamination from original mix or earlier treatments can be associated; confirmation requires chloride profile testing.

• exposure history of the element including any de-icing salt use
• concentration of indicators at splash zones or traffic surfaces
• presence of intense localised corrosion staining or pitting
• areas suitable for chloride sampling at depth where appropriate

“Visual indicators that may be associated with chloride exposure were recorded at the splash zone of the retaining wall, with intense localised rust staining and pitted spalling adjacent to de-iced access steps; chloride profile testing would be required for confirmation.”

Visible features that may suggest low or variable cover to embedded reinforcement.

Surface markings broadly following apparent reinforcement positions; clustered spalls or stains on particular faces; reinforcement visible at very shallow depth where surface loss has occurred.

Original construction tolerances, formwork detailing and earlier surface treatments can be associated.

• areas where reinforcement appears to be at shallow depth
• consistency of spacing between visible indicators
• comparison between different elements or pours
• areas suitable for cover survey using non-destructive testing

“Cover-related indicators were recorded across the soffit, with parallel staining at broadly regular spacing suggesting reinforcement at relatively shallow depth in this zone; cover survey would be appropriate to assess actual cover.”

White or pale crystalline deposits on the concrete surface associated with water movement through the fabric.

White, fluffy or crystalline deposits on the surface, sometimes most prominent at joints, cracks or run-off pathways.

Water movement through the concrete carrying soluble compounds to the surface can be associated.

• extent and location of efflorescence
• association with joints, cracks or run-off pathways
• evidence of repeated occurrence after cleaning
• presence of any associated etching of the surface

“Efflorescence was recorded along the underside of the cantilever, with white crystalline deposits emerging from a horizontal crack and washed across the soffit.”

Mineral deposits associated with water passing through the concrete, sometimes forming stalactites at soffits or cracks.

Hard, white or pale deposits at the underside of cracks or joints, sometimes forming pendant stalactite-like features.

Sustained water movement through cracks or joints can be associated.

• size and extent of deposits
• location relative to cracks, joints or drainage features
• evidence of active water movement
• any associated efflorescence elsewhere on the element

“Lime leaching with stalactite formation was recorded at the underside of the slab, with deposits up to 30 mm long emerging from a crack across the soffit.”

Linear staining associated with rainwater run-off across the concrete face.

Dark or pale streaks running down the face from cills, projections, joints or drainage features.

Drainage detailing, surface roughness, atmospheric deposition and water shedding can be associated.

• location of run-off pathways
• intensity and extent of staining
• association with specific drainage features or projections
• presence of differential weathering between stained and sheltered areas

“Run-off staining was recorded below the projecting cornice, with dark streaks extending the full height of the elevation and concentrated at the joints between panels.”

Variation in surface darkening across the concrete face.

Darker areas in sheltered zones with paler, weathered zones in exposed positions, or vice versa where soiling has been washed by rainfall.

Atmospheric pollution, rainwater wash patterns and surface texture can be associated.

• pattern of soiling relative to exposure
• extent of contrast between dark and pale areas
• any association with overhanging features or drainage
• whether soiling obscures other condition observations

“Differential soiling was recorded across the elevation, with dark deposits in sheltered upper zones and paler, washed surfaces in exposed areas below cills.”

Colonisation of the concrete surface by algae, lichen, moss or higher plants.

Green, black or coloured patches; lichen colonies; moss in textured or sheltered areas; plant growth in joints or cracks.

Moisture retention, surface texture, shading and proximity to vegetation can be associated.

• type of growth where identifiable
• extent and location
• association with damp areas or water shedding features
• any apparent physical effect on the substrate

“Biological growth was recorded across the north-facing wall, with algal staining across the lower 1.5 m and moss colonising debris in the horizontal joint.”

Evidence of water passing through the concrete, visible on the inner or hidden face.

Damp patches, staining, efflorescence or active dripping on the rear or soffit of a wet element.

Cracking, joint failure, deteriorated waterproofing and drainage failure can be associated.

• location of damp patches and any active water
• association with cracks or joints on the wet face
• extent of internal staining or salt deposits
• any effect on adjacent fabric or finishes

“Water tracking through the fabric was recorded on the rear of the retaining wall, with active damp patches and efflorescence corresponding to a horizontal crack on the earth-retaining face.”

Loss of the cement-rich surface exposing the underlying aggregate.

Aggregate visible at the surface where matrix has weathered back; surface texture rougher than original where formed finish survives in sheltered areas.

Long-term weathering of the cement matrix and rainwater run-off can be associated.

• extent of aggregate exposure relative to original finish
• approximate depth of matrix lost where measurable
• comparison with sheltered areas retaining original finish
• any associated loss of arrises or detailing

“Aggregate exposure from weathering was recorded across the exposed upper face of the parapet, with the original board-marked finish surviving only in sheltered zones beneath the coping.”

Small conical losses from the surface associated with individual aggregate particles.

Small craters in the surface, often with a fragment of aggregate at or near the base; typically scattered rather than aligned.

Possible reactive or moisture-sensitive aggregate particles and freeze–thaw action can be associated.

• density and distribution of pop-outs
• approximate size range
• presence of aggregate particles at the base of craters
• concentration on particular faces or exposures

“Pop-outs were recorded across the south elevation, with scattered conical losses 8–15 mm across and aggregate particles visible at the base of several craters.”

Fine cracking patterns that may be associated with internal expansion within the matrix or aggregate, where confirmation requires petrographic examination.

Map cracking, fine pattern cracking sometimes with associated gel exudation or staining; may be more visible when damp.

Possible alkali–aggregate reaction, internal sulfate attack or other matrix-related processes can be associated; confirmation requires laboratory examination.

• pattern, spacing and width of cracks
• presence of any gel-like exudation
• areas suitable for petrographic sampling where appropriate
• comparison between different elements or pours

“Matrix-related cracking was recorded across the plinth panel, with a fine map crack pattern most visible when damp; petrographic examination would be required to investigate possible cause.”

Voided areas in the concrete face where the mortar fraction did not fully fill around the coarse aggregate during placement.

Open, voided texture with exposed coarse aggregate and visible voids; usually associated with formed surfaces.

Original placement and compaction can be associated; the condition typically dates from construction rather than being progressive.

• location and extent of affected areas
• depth of voids where visible
• exposure of any reinforcement within the affected zone
• evidence of earlier repair or patching

“Honeycombing was recorded at the base of the column, with an open, voided texture extending up approximately 300 mm and exposing coarse aggregate.”

A weak, fine surface layer that may be friable or readily dislodged.

Dusty, chalky or readily abraded surface; loose fines visible on the surface or transferred to a finger when lightly touched where appropriate.

Original placement, finishing and curing of the surface can be associated.

• extent of friable surface
• presence of loose fines at the base or on ledges
• comparison with adjacent areas of sound surface
• implications for adhesion of any applied coatings

“Surface laitance and dusting were recorded on the slab, with a friable surface layer producing fine dust where the surface is disturbed.”

Earlier intervention comprising a localised repair of cementitious or polymer-modified material.

Discrete patch of different colour, texture or finish; visible perimeter line; sometimes with associated cracking around or within the repair.

Earlier spalling, reinforcement repair or cosmetic intervention can be associated.

• location, size and apparent age of patches
• condition of the patch material
• presence of cracking at the patch perimeter
• any new staining or spalling emerging at or around the patch

“A patch repair was recorded on the cill, comprising a darker cementitious patch approximately 200 mm long with hairline cracking visible at its perimeter.”

Cracking, opening or loss at the interface between an earlier patch and the surrounding concrete.

Perimeter cracks, lifting at the edges, water tracking at the joint between repair and substrate.

Differential movement between repair and substrate, bond failure and water ingress at the perimeter can be associated.

• extent of perimeter cracking or opening
• evidence of lifting or detachment
• any new staining emerging at the interface
• condition of the surrounding concrete

“Patch repair edge failure was recorded at the cantilever, with continuous perimeter cracking around the earlier patch and rust-coloured staining emerging at the interface.”

Visual indicators that an earlier repair mortar may differ in character from the surrounding original concrete.

Pronounced colour or texture mismatch; differential weathering between repair and substrate; concentrated cracking at or around the repair.

Differences in stiffness, porosity, shrinkage and surface characteristics between repair and substrate can be associated.

• extent of mismatched repairs across the element
• evidence of differential weathering
• association of cracking or staining with repair locations
• any earlier records of the repair programme

“Indicators consistent with repair mortar incompatibility were recorded across the panel, with multiple earlier patches showing pronounced colour mismatch and concentrated cracking at their perimeters.”

Visible ferrous fixings, brackets or pins associated with earlier repair or stabilisation interventions.

Visible bolt heads, brackets or pins, sometimes with associated corrosion staining and damage to the surrounding concrete.

Earlier repair, fixing or stabilisation works can be associated; possible corrosion of the fixing may now affect surrounding concrete.

• location and number of earlier fixings
• condition of visible fixings and any corrosion product
• presence of associated cracking or spalling at the fixing
• evidence of differential movement at the fixing

“Earlier ferrous repair fixings were recorded at the parapet, with two visible brackets showing surface corrosion and associated rust-coloured staining on the adjacent concrete.”

Patchy remains of an earlier applied coating, paint or surface treatment.

Discontinuous coating film, sometimes with lifting edges, sometimes with staining of the substrate where the coating has been lost.

Earlier protective, decorative or anti-graffiti treatments can be associated.

• extent of surviving coating across the element
• condition of remaining coating edges
• any apparent effect on the substrate beneath
• presence of multiple coating layers

“Earlier coating remnants were recorded across the column, with patchy remains of a paint film and lifting edges exposing differential soiling on the substrate.”

Loss of integrity of an applied coating or surface protection system.

Cracked, chalky, faded or thinning coating film; partial loss of finish; exposure of the underlying substrate in places.

Weathering, UV exposure, age and substrate movement can be associated.

• extent and type of breakdown
• exposure of the underlying substrate
• evidence of differential weathering between coated and exposed areas
• any earlier records of the coating system used

“Coating breakdown was recorded across the elevation, with chalking, fading and localised loss of the surface film exposing the substrate in several areas.”

Raised bubbles within a coating film, indicating loss of adhesion to the substrate.

Domed or raised areas in the coating, intact or broken, sometimes containing moisture, salts or substrate debris.

Moisture beneath the coating, salt activity and substrate contamination can be associated.

• size and distribution of blisters
• whether blisters are intact or broken
• any moisture or salt deposits within blisters
• condition of the substrate where exposed

“Coating blistering was recorded on the parapet, with intact and broken blisters across the upper face and salt deposits visible within several broken examples.”

Detachment of a coating in flakes or sheets, exposing the substrate.

Lifted, curled or detached coating fragments; exposed substrate of varying size and condition.

Underlying movement, substrate weakness, moisture and original adhesion can be associated.

• extent of flaking and loss
• size of detached areas
• condition of the exposed substrate
• evidence of progressive loss

“Coating flaking and loss were recorded across the lower face, with detached areas up to 200 mm across exposing differentially soiled substrate beneath.”

Change in colour or appearance of a coating across part or all of an element.

Patchy darkening, yellowing, bleaching or staining of the coating film, sometimes following exposure patterns.

UV exposure, atmospheric pollution, moisture and underlying staining can be associated.

• extent and pattern of discolouration
• association with exposure or run-off patterns
• evidence of staining originating beneath the coating
• comparison with sheltered or less exposed areas

“Coating discolouration was recorded across the elevation, with darkening concentrated below cills and projections in run-off pathways.”

Departure of a horizontal concrete element from its intended profile.

Visible sag or curvature in beams, slabs, balconies or canopies; departure from adjacent straight features; associated cracking on tension or compression faces.

Loading history, support conditions, long-term creep, reinforcement condition and earlier movement can be associated; visual observation alone is not sufficient to confirm cause.

• type and direction of deformation
• approximate magnitude where measurable
• presence of associated cracking
• comparison with adjacent unaffected elements

“Deflection of the cantilever was recorded across its full length, with visible sag of approximately 15 mm at the tip and a hairline crack across the upper face near the support.”

Departure of a vertical concrete element from plumb or from its intended alignment.

Visible lean, tilt or bow; opening or closing of joints on one side; departure from adjacent vertical features.

Ground movement, support conditions, loading and earlier disturbance can be associated.

• direction and approximate magnitude of displacement
• evidence of associated cracking at junctions or supports
• comparison with adjacent vertical features
• any history of past movement

“Displacement of the parapet was recorded across one bay, with an outward lean of approximately 20 mm at the top and associated cracking at the junction with the adjacent bay.”

Visible movement or displacement between adjacent concrete elements or between concrete and other materials.

Stepped or opened junctions, cracking at the interface, displaced finishes or sealants.

Differential thermal movement, settlement, support conditions and original detailing can be associated.

• location and extent of differential movement
• approximate magnitude of displacement
• condition of any sealant or filler at the junction
• evidence of repeated or progressive movement

“Differential movement at the junction was recorded between the concrete frame and the infill panel, with a step of approximately 3 mm and cracking extending up the interface.”

Out-of-plane curvature of a concrete panel or wall element.

Visible bow assessed against a straight edge or by comparison with adjacent elements; sometimes with associated cracking and joint distress.

Thermal movement, moisture gradients, reinforcement condition and original detailing can be associated.

• direction and approximate magnitude of bow
• comparison with adjacent panels
• presence of cracking on convex or concave face
• any associated joint movement

“Bowing of the panel was recorded across one elevation, with an outward bow of approximately 25 mm at mid-height assessed by string line.”

Surface conditions that may be associated with repeated freezing and thawing of moisture within the concrete.

Scaling, pitting and spalling concentrated at horizontal or upward-facing surfaces and water-retaining details; loss often more pronounced on exposed orientations.

Saturation, exposure to freezing cycles, mix characteristics and surface protection history can be associated.

• concentration of damage on particular faces or details
• association with water-retaining features
• extent of scaling, pitting and spalling
• comparison between exposed and sheltered surfaces

“Indicators consistent with freeze–thaw action were recorded on the upper face of the parapet, with concentrated scaling and pitting on the exposed horizontal surface.”

Physical damage from impact, abrasion or external loading.

Dents, gouges, fractured edges, missing fragments and exposed aggregate at impacted areas.

Vehicle contact, traffic, maintenance activity and accidental loading can be associated.

• type, location and extent of damage
• any exposure of reinforcement at impacted areas
• evidence of repeated impact
• implications for adjacent elements

“Impact damage was recorded on the lower corner of the column, with loss of approximately 80 mm of concrete and exposure of two reinforcement bars.”

Surface conditions that may be associated with exposure to fire or sustained high temperature.

Discolouration of the surface, spalling, exposed aggregate, fine cracking and possible loss of cover; sometimes with associated soot deposits.

Past fire exposure or sustained high temperature can be associated; assessment of residual capacity requires investigation.

• extent of affected area
• depth and character of any surface loss
• presence of associated cracking or delamination
• any history of fire or high-temperature exposure

“A fire-affected surface was recorded across the soffit, with pink discolouration, fine cracking and localised spalling consistent with the reported fire event.”

Accumulation of atmospheric deposits on the concrete surface.

Dark deposits, sometimes as discrete crusts or as general darkening; concentrated in sheltered zones.

Atmospheric pollution, exposure history, surface texture and cleaning history can be associated.

• extent and pattern of soiling
• concentration in sheltered or exposed zones
• whether deposits obscure other condition observations
• evidence of associated staining or etching

“Atmospheric soiling was recorded across the elevation, with dark crusts concentrated in sheltered zones beneath projections and paler, washed surfaces in exposed positions.”

Painted, sprayed or marked deposits applied to the concrete surface.

Painted lettering, tagging or marks on accessible surfaces; sometimes with associated staining where earlier removal has been attempted.

Accessibility and exposure can be associated; earlier removal attempts may have affected the substrate.

• extent, location and accessibility of graffiti
• evidence of earlier removal attempts
• any apparent effect of previous removal on the substrate
• presence of multiple layers of paint or marking

“Graffiti was recorded on the lower face of the wall, with sprayed lettering across approximately 1.5 m and faint shadow staining from an earlier removal attempt.”