slight turn in ADA ramp

[Examiner]

I am looking at a plan that has an accessible ramp with a slight turn in the run. Maybe 5-degrees without a landing. How much of a trun can you have before a landing is required? I think that a slight change of cross slope or slope will occure at directional change.

 

[Builder Bob]

None if the clear width is provided and the cross slope remains less than 1 in 48 and the slope runs the same. No where in the ADA or in ANSI is there a section that requires consistency in the slopes or cross slopes.......

I do think that drastic changes in slopes would be bad and create tripping issues..... very gradual changes perhaps not. At least in hte building code, it has a section about consistency for stairs.....

 

[mark handler]

Ramps shall have landings at the top and the bottom of each ramp run. Landings shall comply with 405.7.

Advisory 405.7 Landings. Ramps that do not have level landings at changes in direction can create a compound slope that will not meet the requirements of this document. Circular or curved ramps continually change direction. Curvilinear ramps with small radii also can create compound cross slopes and cannot, by their nature, meet the requirements for accessible routes. A level landing is needed at the accessible door to permit maneuvering and simultaneously door operation.

405.7.4 Change in Direction. Ramps that change direction between runs at landings shall have a clear landing 60 inches (1525 mm) minimum by 60 inches (1525 mm) minimum

 

[ADAguy]

Hi MH, sounds like a dimensional tolerance issue, no? How much is too much, does it limit access? Tree trunk ot building in the way?

 

[Yikes]

Ramps shall have landings at the top and the bottom of each ramp run. Landings shall comply with 405.7. Advisory 405.7 Landings. Ramps that do not have level landings at changes in direction can create a compound slope that will not meet the requirements of this document. Circular or curved ramps continually change direction. Curvilinear ramps with small radii also can create compound cross slopes and cannot, by their nature, meet the requirements for accessible routes. A level landing is needed at the accessible door to permit maneuvering and simultaneously door operation.

405.7.4 Change in Direction. Ramps that change direction between runs at landings shall have a clear landing 60 inches (1525 mm) minimum by 60 inches (1525 mm) minimum

If I understand Mark correctly, the issue is not whether it curves or bends; the issue is whether the curve or bend happens to create a compound slope that is too steep.

Let me take a stab at the implications of this - - you would need to evaluate 2-3 things:

1. Check the slope at the tightest / shortest possible route (the inner radius or bend)

2. Check that the cross slope does not exceed 2%, or that any combination of forward + cross slopes exceed 8.33%.

Also, implied by the words "end of run": Check to make sure the curve or bend still allows a 4' wide path without requiring pivoting or sharply turning on the inside wheel or loss of momentum on one side of the chair (otherwise it might be considered an "end of the run" for that wheel or side).

Did I miss anything?

 

[mark handler]

If I understand Mark correctly, the issue is not whether it curves or bends; the issue is whether the curve or bend happens to create a compound slope that is too steep.Let me take a stab at the implications of this - - you would need to evaluate 2-3 things:

1. Check the slope at the tightest / shortest possible route (the inner radius or bend)

2. Check that the cross slope does not exceed 2%, or that any combination of forward + cross slopes exceed 8.33%.

Also, implied by the words "end of run": Check to make sure the curve or bend still allows a 4' wide path without requiring pivoting or sharply turning on the inside wheel or loss of momentum on one side of the chair (otherwise it might be considered an "end of the run" for that wheel or side).

Did I miss anything?

Basically yes

but the ADASAD also says if you change direction between runs at landings you shall have a clear landing 60 inches minimum by 60 inches minimum

 

[Yikes]

Basically yesbut the ADASAD also says if you change direction between runs at landings you shall have a clear landing 60 inches minimum by 60 inches minimum

I guess we've only been able to give an absolute answer to the O.P. regarding the term "change direction": if the direction on the ramp turns 1 degree, then we need an intermediate landing.

 

[mark handler]

I guess we've only been able to give an absolute answer to the O.P. regarding the term "change direction": if the direction on the ramp turns 1 degree, then we need an intermediate landing.

That is what the ADASAD says....

 

[Msradell]

That is what the ADASAD says....

Well, the code allows curved ramps as long as all of the slope requirements are met. What's the difference between a 5° curve and a 5° turn? As long as the slope requirements can be met I really don't see a problem with this application.

 

[mark handler]

Well, the code allows curved ramps as long as all of the slope requirements are met. What's the difference between a 5° curve and a 5° turn? As long as the slope requirements can be met I really don't see a problem with this application.

Yes, and the ADASAD Also says....."405.7.4 Change in Direction. Ramps that change direction between runs "at landings" shall have a clear landing 60 inches minimum by 60 inches minimum"

If you do not put in a landing you may not need the 60" sq.

 

[ADAguy]

Could the "turn" be viewed as a slight radius and therefore a single run between points, assuming that cross slopes comply?

 

[Examiner]

Thanks for the input. I too agree that a compound slope in direction and cross slope will occur and that a landing will be required due to the turn no matter how slight. The ramp's slope should be uniform in that part of the run of the ramp.

 

[JPohling]

That is correct.