Crack assessment checklist: what to measure and photograph

Before you start

This checklist is for documentation only. It cannot tell you whether a crack is cosmetic or structural, and nothing here is a diagnosis. Print it, fill it in, and share it with a structural engineer or a contractor in your area.

Stop and call for help first if you see any of these: a wall or ceiling that is visibly leaning or sagging, a door frame pulling away from the wall, a gas smell, or water near electrical panels or outlets. For a gas smell, leave the house and call the gas utility or 911 from outside.

Why the record matters: a single look cannot show whether a crack is moving. FPA notes that most slabs are built a little out of level, so even one elevation survey with no baseline cannot prove the slab has moved^[1]. Dated measurements over time are the baseline you can create yourself.

What you need

• A crack width gauge card (a clear plastic card printed with lines of known widths, sold at hardware stores and online)
• A tape measure
• A pencil or fine marker
• A phone camera with date stamps turned on
• A 2 to 4 foot level
• Painter's tape and a notebook or this printout

Part 1: For each crack

Give each crack a number and fill in one block per crack.

Item	What to record	Reading 1 (date)	Reading 2 (date)	Reading 3 (date)
Location	Room, wall or slab area, distance from a corner
Material	Concrete slab, brick, block, drywall, tile, stucco
Width, widest point	Match to the gauge card line
Width, narrowest point	Is one end wider than the other?
Length	End to end, in inches or feet
Direction	Vertical, horizontal, diagonal, stair-step, random web
Vertical offset	Is one side higher than the other? Measure the step
End marks	Pencil line and date at each end. Has the crack grown past it?
Filled or patched before?	Has old filler cracked again?
Water	Damp, stained or leaking at the crack?

Notes on reading the gauge: concrete and masonry cracks usually become noticeable at about 0.04 inch (1.0 mm), and drywall or stucco cracks at about 0.02 inch (0.5 mm)^[1]. Noticeable does not mean serious. Do not use width alone to judge a crack. See the crack width guide for why.

Part 2: Photos

• One wide photo showing where the crack is in the room or on the house
• One close photo of the widest point with the gauge card or a tape measure held flat against it
• One photo of each end mark with its date written beside it
• A side-angle photo if one side of the crack sits higher than the other
• The same angle and the same spot each time you re-measure
• Photos of any water stains, efflorescence (white powder) or rust at the crack

Part 3: Doors, windows and floors

Check	Yes / No	Notes and date
Doors that stick, will not latch, or swing open or shut on their own
Gaps at the top of a door that are wider on one side
Windows that stick or will not lock
Floors that feel sloped. Lay the level in a few spots and note which way the bubble goes
Tile cracks running in a line across several tiles
Gaps between baseboards or cabinets and the floor
Countertops that seem tilted

FPA classes sticking doors and windows, noticeable floor slopes and tilted countertops as functional problems, a step beyond cosmetic cracks^[1]. NAHB guidance says cracks become more likely to signal a structural concern when they come with this kind of distress, and cracks with significant vertical displacement may indicate a structural concern^[4].

Some things look like foundation damage but often are not. FPA lists nail pops and crown molding gaps from wood shrinkage, doors binding from loose hinges, and brick cracks at garage jambs from car impact^[2]. Note them anyway, and let the engineer sort them out.

Part 4: Outside the house

Check	Yes / No	Notes
Soil slopes away from the house on every side
Downspouts discharge well away from the foundation
Water pools near the foundation after rain
Gaps between the soil and the slab edge in dry weather
Large trees or shrubs close to the house (note distance)
Sprinklers or soaker hoses spraying the foundation
Cracks in brick veneer, including stair-step patterns
Gaps around exterior door and window frames

FPA says keeping soil moisture steady around the foundation and directing stormwater away are key to good performance, and that constantly saturated soil harms foundations^[5].

Part 5: Plumbing clues

Check	Yes / No	Notes
Water bill higher than usual with no new use
Water meter moves with all fixtures off
Warm spots on the floor
Damp carpet or flooring with no visible source
Slow drains or sewer smells

Plumbing leaks under a slab can drive foundation movement^[5]. A licensed plumber can test the lines.

Part 6: Repeat and compare

• Re-measure every crack monthly, on about the same date
• Re-measure after very wet and very dry spells
• Note the weather and season beside each reading
• Flag any crack that has grown past its end mark or widened since the last reading

NRMCA advises getting professional advice on active cracks that are widening with time^[3]. NAHB notes that shrinkage cracks in concrete slabs are expected and common and do not compromise structural integrity^[4]. Your readings over time help tell the two apart.

When to call a pro

• Any crack with one side higher than the other, or one that keeps widening between readings.
• Cracks that appear along with sticking doors, sloping floors or tilted counters.
• Horizontal cracks with a bowing or leaning wall, which NAHB guidance calls cause for concern^[4].
• Before you hire anyone for a repair, so an engineer can review this record and do an elevation survey.