Am I SCREWED? - Stairs & building code

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EricG

EricG

10 Year 15 Year
Joined
Jul 12, 2006
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Location
Colorado Springs, CO
I'm in the process of completing a largish (1400 ft^2) 2 story addition on my home. Don't even ask when the first permit was pulled - life intervened for awhile.

Anyway, I recently removed the window and wall from the existing house to make the entrance for the addition. There is a landing there that goes down one step into the 1st floor of the addition, and the steps to the 2nd floor go up from this landing also. I'll post a picture later.

Anyway, this landing and the stairs were done several years ago, and somehow I screwed up the height of the landing wrt the inside floor AND the first step :whoops:

Calling the landing height 0:
Height of interior hardwood flooring: 1 1/4"
Height to top of first stair: 8 1/8"
Height of other stair risers: 7 5/8"

So - to match the riser height on the first step to all the other risers, I only have room for 0.5" of flooring. PITA, but not impossible. But that will leave me 3/4" below the level of the interior floor :bang:

The building code is based on the 2003 International Building code (with ~140 pages of adjustments & exceptions). As I understand it, the max allowable deviation in riser height is 3/8" - so I could possibly get away with 7/8" of flooring and be left with only 3/8" height difference between the landing floor, and the floor of the existing house.

So - any suggestions? Any other loopholes I might be able to take advantage of?

Raising the stairs is not really an option - they are seriously tied into everything. Hardwood stairs also - so adding height on top of the treads isn't feasible either.

Will the difference in floor height be an issue - it will likely be somewhere between 1/2" and 3/4" and I can make that transition over approximately a 6" width.

Thanks!
 
Yep, I'll get on that. Posting from work at the moment and don't have my pics.
 
Here's a quick sketch...
stairs_sketch.webp
 
Unless you house is part of a multifamily complex, you are under the 03' IRC (with local amendments)not the IBC. The IBC has no regulations for single family dwellings.

What is the dimension on the top riser with flooring at the top landing? What type of floor finish do you plan for the bottom, top landing & treads? Your best bet is to limit the flooring thickness at the bottom landing to a max of 7/8". Make sure that no other risers are over 7-5/8" as this will dictate where the 3/8" rule applies.

There is no way around the 3/8" rule. The only way to do it right would be to rebuild the stairs.

Here is an excerpt form the 03 IRC, enjoy :D :

R311.5 Stairways.
R311.5.1Width. 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
shall be 10 inches (254 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). A nosing not less than 3/4 inch (19 mm) but
not more than 11/4 inch (32 mm) shall be provided on
stairways with solid risers. The greatest nosing projection
shall not exceed the smallest nosing projection by
more than 3/8 inch (9.5 mm) between two stories, including
the nosing at the level of floors and landings.
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. Anosing 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:Afloor or landing is not required at the top of
an interior flight of stairs, provided a door does not swing
over the stairs.
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).
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 riser of the flight to a point directly
above lowest riser of the flight. Handrail ends shall be returned
or shall terminate in newel posts or safety terminals.
Handrails adjacent to awall shall have a space of not
less than 11/2 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.
2. The use of a volute, turnout, starting easing or
starting 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 (160mm)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 (19mm)
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 (32mm)to a
maximum of 23/4 inches (70 mm). Edges shall have
a minimum radius of 0.01 inches (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. Circular stairways, spiral
stairways, winders and bulkhead enclosure 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.
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.
 
beaufort-fj60 said:
could you bump up your landing to the first step?
Click to expand...

Creating a landing that steps down 8-1/4" into the opening should work also (good idea) as this step would not be part of the flight of stairs. you need to to take the floorplan into account to make sure that this step create no other code violations.

Before you do anything, you should ask your inspector first. If they don't like your'e compliance methods they can make your job miserable. :rolleyes:
 
beaufort-fj60 said:
could you bump up your landing to the first step?
Click to expand...

Interesting idea, but I don't think it will work. In the sketch below the blue area is the entryway from the old house into the addition. So as you come through that doorway, you would have to step up onto the landing, and then 2 steps later, down into the addition.

Also, that entryway is just a standard door height - there wouldn't be enough clearance - at least not for me @ 6'3"
stairs_sketchb.webp
 
sixty said:
Unless you house is part of a multifamily complex, you are under the 03' IRC (with local amendments)not the IBC. The IBC has no regulations for single family dwellings.
Click to expand...

Yea, just realized this today when I got a copy of the IBC. Thanks for the quotes from the IRC below!

What is the dimension on the top riser with flooring at the top landing?
Click to expand...

I'll measure when I get home - but it should equal 7 5/8" with 3/4" of finish floor (hardwood) on top.

What type of floor finish do you plan for the bottom, top landing & treads?
Click to expand...

Top landing will be hardwood, treads are oak, bottom landing may be hardwood, or a hardwood border with slate tile inset.

Your best bet is to limit the flooring thickness at the bottom landing to a max of 7/8". Make sure that no other risers are over 7-5/8" as this will dictate where the 3/8" rule applies.
Click to expand...

Yea, that's the best I've come up with - take full advantage of the allowed 3/8" variance to get the lower landing floor as high as possible.

There is no way around the 3/8" rule. The only way to do it right would be to rebuild the stairs.

Here is an excerpt form the 03 IRC, enjoy :D :

R311.5 Stairways.
R311.5.1Width. 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
shall be 10 inches (254 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). A nosing not less than 3/4 inch (19 mm) but
not more than 11/4 inch (32 mm) shall be provided on
stairways with solid risers. The greatest nosing projection
shall not exceed the smallest nosing projection by
more than 3/8 inch (9.5 mm) between two stories, including
the nosing at the level of floors and landings.
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. Anosing 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:Afloor or landing is not required at the top of
an interior flight of stairs, provided a door does not swing
over the stairs.
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).
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 riser of the flight to a point directly
above lowest riser of the flight. Handrail ends shall be returned
or shall terminate in newel posts or safety terminals.
Handrails adjacent to awall shall have a space of not
less than 11/2 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.
2. The use of a volute, turnout, starting easing or
starting 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 (160mm)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 (19mm)
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 (32mm)to a
maximum of 23/4 inches (70 mm). Edges shall have
a minimum radius of 0.01 inches (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. Circular stairways, spiral
stairways, winders and bulkhead enclosure 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.
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.
Click to expand...
 
sixty said:
See section R311.5.5. You are limited to a 1:48 slope on landings.
Click to expand...

The area where I'll need to make this slope is adjacent to the landing, in the entryway (blue in picture). As I read it, the landing is defined as an area the width of the stairs, extending 36" in the direction of travel. This sloped area would be just outside of the width of the stairs.

It will make more sense when I get a picture up.

And yes, I plan to consult with the inspector before doing anything here.
 
A raised landing will work, except the min. head clearance is in the IRC 6'-8".

I think a hardwood bottom landing with a tapered transition strip (maybe 3-6" wide, but located somewhere to provide continuity) from the landing area to the adjacent finish floor would work out & not look too out of place. Just make sure the tapered strip is not located in the code required landing area. Be sure & check the IRC ammendments for your area to make sure they haven't ammended something beyond what is required by the IRC ( I have seen some pretty strange ammendements!).

Edit: the above info was posted prior to reading you last post :D
 
Here's a picture finally. The area outlined in blue is where I propose to make the 3/8" -> 3/4" transition ramp.
landing_stairs_b.webp
 
sixty said:
The transition strip should look fine. I would try to make it the width of the opening but that will alot more work than thin steeply tapered strip.
Click to expand...

I don't think it will be that hard to make a full width transition. I have a 12" planer, so I'll just make a jig that holds one edge of the board 3/8" higher then the other. Then run it through the planer, stepping down the thicknes until you get a full width pass.
 
i dont know how big the landing is and how it is attached to the floor but maybe you could take out the top plywood subfloor and put something thinner. This allows a level area and you could split the difference between the riser and the threshold opening in the entrance to the room. You could put 2x(4,6,8,etc) widthwise underneath the new thinner subfloor to prevent flexing. Maybe forget the thin subfloor and build the finished floor directly on solid wood if the inspector/codes allows it. Just throw ideas around.
 
beaufort-fj60 said:
so, what did you do?
Click to expand...

I'm going to make the final decision this weekend when I set the height for the landing step.

But I think I will make the first step as short as possible, taking full advantage of the allowed 3/8" variance. Then I'll make up the difference (between 1/4" and 3/8") between the inside floor and the landing floor by making a sloped piece for the transition through the doorway.

Not perfect, but not to bad.
 
Three thoughts come to mind on several projects when I am dealing with building officials.

First one, whip out my PE seal and they don't question it (this ain't gonna help you here)

Second, get with the building official and see what he (or she) can come up with. You might be able to get a written exception. The main issue with consulting them on it is the fact that - if you ask the question, it begs an answer.

Third, it is easier to ask for forgiveness than for permission. Not necessarily the best approach and could cost you some money in the end.

I would try and slim the landing hardwood down as much as possible and you might be okay. Could you plane the boards down a bit and use thinner pieces there? More than likely, you could get it close and it would pass inspection with flying colors :grinpimp:

bk
 
archie said:
i dont know how big the landing is and how it is attached to the floor but maybe you could take out the top plywood subfloor and put something thinner. This allows a level area and you could split the difference between the riser and the threshold opening in the entrance to the room. You could put 2x(4,6,8,etc) widthwise underneath the new thinner subfloor to prevent flexing. Maybe forget the thin subfloor and build the finished floor directly on solid wood if the inspector/codes allows it. Just throw ideas around.
Click to expand...

What he said. If you pull the OSB and put the 1 1/4 hardwood right on the framing it should put you where you need to be. you could put cleats and reset the OSB between the framing flush with the top.


Kevin
 
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