National Association of Certified Home Inspectors

InterNACHI’s advanced tips for inspecting stairways and sample reporting language.

Stairways are some of the most hazardous areas of a home and stair falls are often fatal. The following are some advanced tips (based largely on building codes) for inspecting a stairway followed by some suggested language (narratives) for report writing. This level of inspection is far beyond what an inspector would do on a general home inspection and far exceeds InterNACHI’s Standards of Practice.

The handrail:

Determine if the stairway should have a handrail. Any stairway of 4 or more risers should have a handrail on at least one side.
Measure the handrail height. The handrail height should be at least 34 inches and no more than 38 inches. Handrail height is measured vertically from the sloped plane adjoining the tread nosing. (Exception: When there is a continuous handrail transition between flights, the transition from handrail to guardrail, the handrail height at the transition can be greater than the maximum.)
Determine if it is continuous. The handrail should be continuous for the full length of the flight of stairs, measured from a point directly above the top riser to a point directly above the lowest riser of the flight. (The use of a volute, starting easing, or turnout can be installed over the lowest tread.)
Handrails should end at a newel post or a wall.
Handrails adjacent to a wall should have a space of not less than 1 and ½ inches between the wall and the handrails.
Check the handrail attached to the wall. The wall handrail should have attachment devices to transfer a concentrated load of 200 pounds applied in any direction to the structural wall.

The width of the stairway:

Measure the width of the stairway. Stairways should be at least 36 inches wide. This is measured at all points above the handrail height and below the required headroom height.
For spiral stairways, there should be a width of at least 26 inches measured at and below the handrail.
Measure handrail projections. Handrails should not project more than 4 and ½ inches on either side of the stairway.
Measure the width when there’s one handrail. Where a handrail is installed on one side, the minimum clear width of the stairway at and below the handrail height should not be less than 31 and ½ inches.
Measure the width when there are two handrails. Where handrails are installed on both sides, the minimum clear width of the stairway at and below the handrail height should not be less than 27 inches.
Do not be concerned about projections of 4 and ½ inches or less located below the level of the handrail, including treads, trim, stringers or other items. The width limitations are based upon the body’s movements as a person walks on a stairway.

The risers and treads:

Measure the risers and tread runs.
Make sure the riser height is at most 7 and ¾ inches. For spiral stairs, the maximum rise should be 9 and ½ inches.
Measure the difference between the riser heights. The greatest riser height within any flight of stairs should not exceed the smallest by more than 3/8 of an inch.
Make sure the riser height is at least 4 inches.
Make sure the tread depth is at least 10 inches.
For spiral stairs, all treads should be identical. And each tread should have at least a 7 and ½ inch tread depth at 12 inches from the narrower edge.
For winder stairs, treads should have a tread depth of at least 10 inches measured at a point 12 inches from the side where the treads are narrower. Winder treads should have a tread depth of at least 6 inches at any point.
Measure the difference between the tread depths. The greatest tread depth within any flight of stairs should not exceed the smallest by more than 3/8 of an inch. For winders, this is measured at the 12 inch walk line.
Check the slope. The walking surface of the stairway treads and landings should be sloped no steeper than ¼-inch vertical in 12 inches horizontal (a 2% slope).
Check for cracked, damaged or loose treads.

The nose:

On stairways with solid risers, there should be a nosing at least ¾ of an inch and not more than 1 and ¼ inches.
The radius of a nosing curve should be no greater than 9/16of an inch.
A nosing is not required when the tread depth is at least 11 inches.

The guards:

Inspect the guards. Guards should be constructed so that they prevent people from falling over them and prevent children from crawling through them.
Check for strength. The design strength of a guard should handle a 200-pound concentrated load applied at any point in any direction along the handrail or top of the guard.
Measure the height of the elevated floor level. All decks and porches, including those with insect screening, landings, balconies, ramps, or raised floor surfaces located more than 30 inches above the floor or ground below should have guards. A guard is necessary at those elevated floor areas, because a fall from that height can result in injury.
Measure the guard height at the elevated floor level. The height of the guard should be at least 36 inches.
Measure the total rise of the stairway. Open sides of stairways with a total rise of more than 30 inches above the floor or ground below should have guards not less than 34 inches in height. This is measured vertically from the nosing of the treads.
Intermediate rails or balusters should be able to withstand a horizontal load of 50 pounds on an area equal to one square foot.
Inspect for a common defect found at the guard that is a cracked, loose or missing intermediate rail.
Guards should not have horizontal or ornamental patterns that would provide a ladder effect for children.

The spheres:

Use the 4-inch sphere. Guards at open sides of stairways, raised floor areas, balconies and porches should have intermediate rails or ornamental enclosures that do not allow passage of a 4-inch diameter sphere.
Use the 4-inch sphere. Open risers should not allow the passage of a 4-inch diameter sphere. On stairs with a total rise of 30 inches or less, the size of the open riser is not limited.
Use the 6-inch sphere. The triangular area formed by a tread, riser and guard should not allow passage of a 6-inch diameter sphere.
Use the 4 and 3/8-inch sphere. The opening at guards on the sides of stair treads should not allow the passage of a 4 and 3/8-inch diameter sphere.

The handgrip:

Inspect the handgrip portion of the handrail. The handgrip can be a 2-inch circular handgrip or a non-circular handgrip.
A circular handgrip has a cross section minimum of 1 and ¼ inches and a maximum of 2 inches.
A non-circular handgrip with a perimeter minimum of 4 inches and a maximum of 6 ¼ inches should have a maximum cross section of 2 and ¼ inches.
A non-circular handgrip with a perimeter greater than 6 and ¼ inches should have a graspable finger recess on both sides.
All handrails should be equivalently graspable to the 2-inch circular handgrip. The handgrip shape should provide a graspable surface. It should allow the user to maintain a consistently secure natural grasp on the handrail without twisting the fingers or requiring release.

Above and below:

Inspect above the stairs, the headroom. The headroom in all parts of a stairway should not be less than 6 feet and 8 inches. It is measured vertically from the sloped plane adjoining the tread nosing or from the floor surface of the landing or platform. Spiral stairways should have headroom of at least 6 feet and 6 inches.
Inspect below the stairs. Enclosed accessible space under stairs should be protected on the enclosed side with 1/2-inch gypsum board.
At the bottom of the stair stringer boards, check for water damage.
Inspect below the stairs for mold and damage caused by insect infestation.

Landings:

Inspect the landings. A floor or landing is required at the top and bottom of a stairway. There is an exception: A floor or landing is not required at the top of an interior flight of stairs, including stairs in an enclosed garage, provided a door does not swing over the stairs.
Inspect the total rise of the stairway. A stairway should not have a vertical rise larger than 12 feet between floor levels or landings.
Inspect the width of the landing. Every landing should be at least 36 inches wide, measured in the direction of travel. The width of the landing should not be less than the width of the stairway.

Illumination:

Check for lighting at the stairs. All interior and exterior stairways should have a means to illuminate the stairs, including landings and treads.
Check for lighting at the landings. Interior stairways should have a light located at each landing, except when a light is installed directly over each stairway section.
Check for controls. Interior stairways with at least 6 risers require wall switches at each floor level, unless the lights are continuously illuminated or automatically controlled.
Exterior stairways should have a light located at the top of the stairway.
Exterior stairways from the outside ground level to a basement should have a light at the bottom of the stairway.
Lights at an exterior stairway should be controlled from inside the property.

Sample reporting language: