must or may

[sunyaer]

This is a quiz question about Ontario Building Code:
---------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------

It looks to me that a tactile attention indicator shall be installed only when both condition (a) and (b) are satisficed. If a platform (the exit passageway) is not higher than 250 mm above the finished floor, even there is no guards installed, tactile attention indicator is still not required.

So, my opinion is that the word "must" in the question should be "may", please comment.

 

[bill1952]

If it says "may" than it simply means those thing are permitted but none of them is required. I don't like the term "must" in codes and standards. Clearer to say is required.

 

[sunyaer]

If it says "may" than it simply means those thing are permitted but none of them is required. I don't like the term "must" in codes and standards. Clearer to say is required.

What I am trying to say is that the tactile attention indicator is required only when the platform is more than 250 mm higher than finished floor or ground. So, the “must” in the quiz question is not appropriate, rather “may be taken”.

Am I correct?

 

[bill1952]

Or there needs to be a none of the above answer.

Could be the question writer got confused by the slope aspect and thought 1 in 4 was greater than 1 in 3, a common error. That would make it all correct.

 

[tmurray]

I can understand where you are coming from, but the question is worded correctly. Think about the difference like this:

The contractor "may" choose a compliant option. - Implies that the contractor can choose an option, but also can choose to do nothing. Used typically when if something is done, it must be done a certain way, but they are not actually required to do it in the first place.
The contractor "must" choose a compliant option. - Implies that the contractor must choose from one of the options. They cannot choose to do nothing.

The question is striking e as odd though...

The specific code section says:

(1) A tactile attention indicator conforming to Article 3.8.3.18. shall be installed along the edge of any platform that is,
(a) not protected by a guard, and
(b) higher than 250 mm above finished floor or ground or sloped steeper than 1 in 3.

In our case, the question is silent on the difference in elevation between the passageway and the adjacent ground, so we would assume it is level.

There is a sloping grade, but at only 1 in 4, it is not steep enough to trigger this clause since it only applies in 1 in 3 or steeper.

In this case, it would need neither a guard or a tactile indicator. This is a bad question.

 

[wwhitney]

The first sentence in the test question is worded imprecisely. I expect the question writer is making assumptions equivalent to the following rewording:

"A level exterior exit passageway is constructed of concrete and is located above an adjacent sloped surface of 1 in 4."

Then if the passageway is at least 1m long, a reasonable expectation for anything called a passageway, since it is above the adjacent surface it will be at least 250 mm above that surface at some point, given the 1 in 4 grade difference.

Cheers, Wayne

 

[bill1952]

The first sentence in the test question is worded imprecisely. I expect the question writer is making assumptions equivalent to the following rewording:

"A level exterior exit passageway is constructed of concrete and is located above an adjacent sloped surface of 1 in 4."

Then if the passageway is at least 1m long, a reasonable expectation for anything called a passageway, since it is above the adjacent surface it will be at least 250 mm above that surface at some point, given the 1 in 4 grade difference.

Cheers, Wayne

I thought the slope was perpendicular to the ramp but it seems you think it's in the direction of travel on the ramp. You could be right. Both the question and answers as well as the code is not clearly written.

 

[tmurray]

I thought the slope was perpendicular to the ramp but it seems you think it's in the direction of travel on the ramp. You could be right. Both the question and answers as well as the code is not clearly written.

You are correct. Guards under Canadian codes are required under two situations. One is a difference in elevation and the other is the slope of grade.