Planning & Development Linn County Code Linn County, IA Residential Guidelines

Building Division & Railings Page 1 of 4

Stairs & Railings

6' - 8 " Minimum Headroom

Applies to One & Two Family Dwellings

Ends of handrail returned to or terminated in newel post 34" - 38" to top of handrail

Handrails continuous to a point directly above the top and bottom riser

TREADS and RISERS: § Maximum riser is 7-3/4" and the minimum tread depth is 10". Risers and treads shall be uniform throughout flight. § The greatest riser height shall not exceed the smallest by more than 3/8". § The greatest tread shall not exceed the smallest by more than 3/8". § The minimum headroom in all parts of the stairway shall not be less than 6' - 8" measured from a sloped plane adjoining the tread nosings.

HANDRAILS:

§ Shall be continuous the full length of the stairs from a point directly above the top riser of a flight to a point directly above the lowest riser of the flight. § A handrail is required on at least one side of stairs with four or more risers. § The top of the handrail shall be placed not less than 34 inches and not more than 38 inches above the nosing of the treads. § Ends of handrails shall be returned to the wall or shall terminate in a newel post. Linn County Planning and Development Guidelines Page 2 of 4

Guards

Guards Required:

o , decks, , ramps or raised surfaces located more than 30 inches above the floor or grade below shall have guards not less than 36 inches in height. o Open sides of stairs with a total rise of more than 30 inches above the floor or grade below shall have guards not less than 34 inches in height measured vertically from the nosing of the treads.

Guard Opening Limitations:

o Required guards shall have intermediate rails or ornamental closures that do not allow passage of a sphere 4 inches in diameter.

Exceptions: o The triangular openings formed by the riser, tread, and bottom rail of a guard at the open side of a stairway are permitted to be of such a size that a sphere 6 inches in diameter cannot pass through. o Openings for required guards on the sides of stair treads shall not allow a sphere 4 - 3/8 inches to pass through.

4-3/8" 4"

Min. 36"

4"

Min. Walking Surface 3 4"

6" > 30"

Floor or grade below

Linn County Planning and Development Guidelines Page 3 of 4

Handrails

Continuity: Handrail Detail Winder Details Continuous handrail required Handrails allowed to be the full flight of the stairs interrrupted at landing Approved Handrail is not Min continuous Dn Dn Min. 36" 36" Min Not Approved 36" x 36" Width Landing

Newel post may interrupt handrails at turns Ends returned to wall

Winder Deta il Top of handrail 34" - 38" above nose of tread Up Up Min. 10" Up Up 31-1/2" 12" Min End terminated in 36" newel post Min. 6" Approved Handrail Shapes Clearance: 1-1/2" minimum Other shapes may be acceptable if they provide equivalent graspability between the handrail & wall 2-3/4" Max 1-1/4" Min 4-1/2" Max Projection x a n M i

" x " M 4 1-1/2" Min a 2 " / 4 " / 3 M 1 4 Clearance n - / i 1 3 - M n 1 i " 1

M

3/8" 2-3/4" Max 1-9/16"

x " /

a 4 n / " i 3 - 3 M 4 M 1 x n

" a io

6 t M c 1 "

/ e /4 S 9 1 - - s

1 2 s 5/16" ro C

Not Approved Shapes 2-3/4" Max

Flat 2 x 4 x " a

4 / " 3 M 4 n / 2" i 3 - M 1

n " i

3/8" 1 M " Max 6 4" 2-1/ tion 1 ec / S ross 7 C

Linn County Planning and Development Guidelines Page 4 of 4

Tread Detail

Treads & Risers shall be uniform throughout flight Maximum Minimum 10" Radius = 9/16" Tread Depth " 4 t / Nosing Required h 3 - g i 7

e Min. 3/4" m H

Max 1-1/4" u r e m i s i x R a

M Solid Riser

STAIR PROFILE: NOSING REQUIRED: § A nosing not less than 3/4" and not more than 1-1/4" shall be provided on stairs with solid risers. § The greatest nosing projection shall not exceed the smallest by more than 3/8 inch. § A nosing is not required where the tread depth is a minimum of 11 inches. RISERS: § Risers shall be solid or § May be open risers if the opening between treads does not permit the passage of a 4" diameter sphere.

www.linncounty.org/planning 935 2nd Street SW Cedar Rapids, IA 52404 Phone 319.892.5130 Fax 319.892.5155 Revised 7/17/20