Thread: Risers

I have a problem and I am trying to work out a solution.

I had a contractor work on my stairs. Long story short, failed inspection. I am trying to get a better understanding as to what he needs to accomplish so I don't have this problem again.

I believe the building code states that risers need to be less than 7" and no more than 3/8" variation.

Total stair height (top floor to bottom floor) = 136"

136"/18 risers = 7.55

Making the math to make changes, I can get all of my risers to be under 7" falling within the 3/8" variation. However, when I put my 1" tread on, they exceed 7" and are closer to the 7.55"

By default, am outside of code?


Mike

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Originally Posted by Mike Douglas

I have a problem and I am trying to work out a solution.

I had a contractor work on my stairs. Long story short, failed inspection. I am trying to get a better understanding as to what he needs to accomplish so I don't have this problem again.

I believe the building code states that risers need to be less than 7" and no more than 3/8" variation.

Total stair height (top floor to bottom floor) = 136"

136"/18 risers = 7.55

Making the math to make changes, I can get all of my risers to be under 7" falling within the 3/8" variation. However, when I put my 1" tread on, they exceed 7" and are closer to the 7.55"

By default, am outside of code?


Mike

You need to check with the person that failed the first inspection and findout exactly what he/she is wanting to see. You are under the FL building code; under the IRC which I think the FL code is based on you can have a max riser height of 7 3/4" with no more than 3/8" variation between the tallest and shortest riser.

If you can't get it to work then you might need to break up the stairs with a properly sized landing. This is one reason you see landings in the the middle of some stairs!

Originally Posted by Mike Douglas

I have a problem and I am trying to work out a solution.

I had a contractor work on my stairs. Long story short, failed inspection. I am trying to get a better understanding as to what he needs to accomplish so I don't have this problem again.

I believe the building code states that risers need to be less than 7" and no more than 3/8" variation.

Total stair height (top floor to bottom floor) = 136"

136"/18 risers = 7.55

Making the math to make changes, I can get all of my risers to be under 7" falling within the 3/8" variation. However, when I put my 1" tread on, they exceed 7" and are closer to the 7.55"

By default, am outside of code?


Mike

#1. IRC is 7.75" max. riser, UBC is 8".

#2. Correct me if I am wrong, but doesn't every rise increase by the thickness of the tread? Meaning only the top and bottom steps change total rise height.

The problem / solution is going to be difficult for me to "blame" the appropriate party.

Just moved into a new home. Prior to having work done, the stairs were to code.

I had a new railing installed. Got a permit and it was installed to code.
Simultaneously, had wood flooring company install new risers and treads.


Because of the railing and how it was installed (brackets securing the posts) it forced the wood flooring company to change the riser heights with plywood in some instances to cover the Medal L brackets used to secure the post.


Some significant changes are going to happen and thus far neither party is taking responsibility.


I've been calling the building department for 2 days, left messages, emails and yet to get a response. I want to know exactly, what the code is.

Can you tell me from PBC Building Code Standards

where the code is written?

I asked the inspector where he was here and he said its in black and white however, I haven't found it and I've been through it several times.

How can I find out if its IRC or UBC?

Mike

Scott

BTW, thank you for your timely reply and explanation. Thats been a rarity for me the past few days with my issue.

Mike

Originally Posted by Mike Douglas

Scott

BTW, thank you for your timely reply and explanation. Thats been a rarity for me the past few days with my issue.

Mike

You're welcome.. Most on this discussion board you will find are helpful, you just caught me at the computer doing some research on an issue I'm working on that happens to involve a set of stairs!

When dealing with a building/codes department phone calls are not the best way.. I have found that an in person visit works best, and usually the best time is late in the afternoon or just as they open the doors in the morning.

IRC 311.5.3.1

UBC 1003.3.3.3

Mike,

Its FBC, (Florida Building Code) not IRC or UBC



R311.5 Stairways.

R311.5.1 Width. Stairways shall not be less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Handrails shall not project more than 4.5 inches (114 mm) on either side of the stairway and the minimum clear width of the stairway at and below the handrail height, including treads and landings, shall not be less than 31.5 inches (787 mm) where a handrail is installed on one side and 27 inches (698 mm) where handrails are provided on both sides.

Exception: The width of spiral stairways shall be in accordance with Section R311.5.8.

R311.5.2 Headroom. The minimum headroom in all parts of the stairway shall not be less than 6 feet 8 inches (2036 mm) measured vertically from the sloped plane adjoining the tread nosing or from the floor surface of the landing or platform.

R311.5.3 Stair treads and risers.

R311.5.3.1 Riser height. The maximum riser height shall be 73/4 inches (196 mm). The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm).

R311.5.3.2 Tread depth. The minimum tread depth, exclusive of nosing, shall be not less than 9 inches (229 mm). Treads and risers of stairs shall be permitted to be so proportioned that the sum of two risers and a tread, exclusive of projection of nosing, is not less than 24 inches (610 mm) nor more than 25 inches (635 mm). The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread's leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm). Winder treads shall have a minimum tread depth of 10 inches (254 mm) measured as above at a point 12 inches (305) mm from the side where the treads are narrower. Winder treads shall have a minimum tread depth of 6 inches (152 mm) at any point. Within any flight of stairs, the greatest winder tread depth at the 12 inch (305 mm) walk line shall not exceed the smallest by more than 3/8 inch (9.5 mm).

R311.5.3.3 Profile. The radius of curvature at the leading edge of the tread shall be no greater than 9/16 inch (14.3 mm). Every tread less than 10 inches (254 mm) wide shall have a nosing or effective projection of approximately 1 inch (25 mm) over the level immediately below that tread. Beveling of nosing shall not exceed 1/2 inch (12.7 mm). Risers shall be vertical or sloped from the underside of the leading edge of the tread above at an angle not more than 30 (0.51 rad) degrees from the vertical. Open risers are permitted, provided that the opening between treads does not permit the passage of a 4-inch diameter (102 mm) sphere.

Exceptions:

1. A nosing is not required where the tread depth is a minimum of 11 inches (279 mm).

2. The opening between adjacent treads is not limited on stairs with a total rise of 30 inches (762 mm) or less.

R311.5.4 Landings for stairways. There shall be a floor or landing at the top and bottom of each stairway.

Exception: A door at the top of a stair shall be permitted to open directly at a stair, provided the door does not swing over the stair.

A flight of stairs shall not have a vertical rise greater than 12 feet (3658 mm) between floor levels or landings.

The width of each landing shall not be less than the stairway served. Every landing shall have a minimum dimension of 36 inches (914 mm) measured in the direction of travel.

R311.5.5 Stairway walking surface. The walking surface of treads and landings of stairways shall be sloped no steeper than one unit vertical in 48 inches horizontal (2-percent slope).

R311.5.6 Handrails. Handrails shall be provided on at least one side of each continuous run of treads or flight with four or more risers.

R311.5.6.1 Height. Handrail height, measured vertically from the sloped plane adjoining the tread nosing, or finish surface of ramp slope, shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm).

Exception: When fittings are used to provide transition between flights, transition from handrail to guardrail, or used at the start of a stair, the handrail height at the fitting shall be permitted to exceed the maximum height.

R311.5.6.2 Continuity. Handrails for stairways shall be continuous for the full length of the flight, from a point directly above the top nosing edge of the flight to a point directly above the lowest nosing edge of the flight. Handrail ends shall be returned or shall terminate in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of no less than 1-1/2 inch (38 mm) between the wall and the handrails.

Exceptions:

1. Handrails shall be permitted to be interrupted by a newel post at the turn and at the top of the flight.

2. The use of a volute, turnout, starting easing or newel shall be allowed over the lowest tread.

R311.5.6.3 Handrail grip size. All required handrails shall be of one of the following types or provide equivalent graspability.

1. Type I. Handrails with a circular cross section shall have an outside diameter of at least 11/4 inches (32 mm) and not greater than 2 inches (51 mm). If the handrail is not circular it shall have a perimeter dimension of at least 4 inches (102 mm) and not greater than 61/4 inches (160 mm) with a maximum cross section of dimension of 21/4 inches (57 mm).

2. Type II. Handrails with a perimeter greater than 61/4 inches (160 mm) shall provide a graspable finger recess area on both sides of the profile. The finger recess shall begin within a distance of 3/4 inch (19 mm) measured vertically from the tallest portion of the profile and achieve a depth of at least 5/16 inch (8 mm) within 7/8 inch (22 mm) below the widest portion of the profile. This required depth shall continue for at least 3/8 inch (10 mm) to a level that is not less than 13/4 inches (45 mm) below the tallest portion of the profile. The minimum width of the handrail above the recess shall be 11/4 inches (32 mm) to a maximum of 23/4 inches (70 mm). Edges shall have a minimum radius of 0.01 inch (0.25 mm).

R311.5.7 Illumination. All stairs shall be provided with illumination in accordance with Section R303.6.

R311.5.8 Special stairways. Spiral stairways, bulkhead enclosure stairways, and circular stairways shall comply with all requirements of Section R311.5 except as specified below..

R311.5.8.1 Spiral stairways. Spiral stairways are permitted, provided the minimum width shall be 26 inches (660 mm) with each tread having a 71/2-inches (190 mm) minimum tread depth at 12 inches from the narrower edge. All treads shall be identical, and the rise shall be no more than 91/2 inches (241 mm). A minimum headroom of 6 feet 6 inches (1982 mm) shall be provided. Handrails shall be provided on one side.

R311.5.8.2 Bulkhead enclosure stairways. Stairways serving bulkhead enclosures, not part of the required building egress, providing access from the outside grade level to the basement shall be exempt from the requirements of Sections R311.4.3 and R311.5 where the maximum height from the basement finished floor level to grade adjacent to the stairway does not exceed 8 feet (2438 mm), and the grade level opening to the stairway is covered by a bulkhead enclosure with hinged doors or other approved means.

R311.5.8.3 Circular stairways. Circular stairs may have a minimum tread depth of 9 inches (229 mm) with 1 inch (25.4 mm) of nosing, and the smaller radius may be less than twice the width of the stairway.


Dom.

Thanks Dom.

Keep your eyes glued to the post. Meeting with both contractors tomorrow.


Mike

Originally Posted by Mike Douglas

I have a problem and I am trying to work out a solution.

I had a contractor work on my stairs. Long story short, failed inspection. I am trying to get a better understanding as to what he needs to accomplish so I don't have this problem again.

I believe the building code states that risers need to be less than 7" and no more than 3/8" variation.

Total stair height (top floor to bottom floor) = 136"

136"/18 risers = 7.55

Making the math to make changes, I can get all of my risers to be under 7" falling within the 3/8" variation. However, when I put my 1" tread on, they exceed 7" and are closer to the 7.55"

By default, am outside of code?


Mike

"However, when I put my 1" tread on"

That's the part where you begin to lose me.

The stringers will all be cut to 7.55" (make it 7-9/16", or 7.5625", 7.5625 X 18 = 136.125, or 1/8" over at the top riser), the tread will go one the stringers and match up all the way up.

The only compensations you need to make will be for the first riser to allow for the finish floor thickness if less than the tread thickness or if more than the finish floor thickness, and, at the top riser for the finish floor thickness there too.

If you forget to compensate for the top and bottom, or one or the other, you will end up wrong at either or both risers - and you are only allowed a maximum variation from the tallest riser to the shortest riser of 3/8".

The stairs are really easy to do ... unless the first and/or last risers are not compensated for the finish floor heights if different than the tread thickness - those are the two areas where most mistakes in riser heights are made.

Added with edit: I did not include this at first because it is in the code Dom posted, but I just want to repeat it: the allowable maximum riser height is 7-3/4".

Mike,
Are you just laminating over existing stairs?
It sounds like the flooring guy changed the elevations on you. First, it does not sound right that the rail contaractor used brackets for the knewel posts and they needed to add plywood to cover the brackets. They are typically notched into the nosing and fastened through the post into the riser or if its an intermediate post at a upper floor balcony you drill a dowel in the bottom of the intermediate posts and then into the floor and glue it in place and then the two angles of the handrail lock it in.

When you make stairs, you measure from first level finish floor to second level finish floor(with bullnose) as you have and mark and cut the run and rise out. with that completed, you cut the thickness of the tread off the heal of the bottom of the stringers that supports the treads.This way when you measure each risers, they are the same.So say I cut the riser measurments at 71/2"inches, my first riser cut before the 1" tread is installed is 6 1/2' inches, then as I install each tread i will get 71/2"

In millwork when a house is built, the stair company would of asked what the finish floor was going to be and adjusted accordingly and the carpenter would of set the stairs and shimmed the bottom 1/2",3/4" or 1" inch, what ever the finish floor was to be, carpet, tile or hardwood.

When the flooring contractor installed the flooring on the first tread and top tread you were in trouble unless you raise the first floor and second floor elevations to match, if I am reading you correct.