# Threshold Question



## NJDave (Sep 7, 2013)

Hello,

Are there any building codes that apply to the difference in height between the floors in two adjoining rooms or to the height of a threshold leading to the top of an interior staircase?

We are leveling the entire first floor of a home.  We can't jack up the floor, can't remove the existing plywood subfloor and can't afford to add the weight of SLC, so our approach will be to add sleepers on top of the existing plywood, then another layer of plywood, then hardwood.  We don't have any height issues with any of the exterior doors but at the threshold leading to the top of the stairs to the basement, we will be adding 2.5".  So, we are looking for a way to deal with the threshold that is compliant with building code and also cosmetically acceptable.

Thanks much for the help.

Dave


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## ICE (Sep 7, 2013)

That sounds like you are adding 2.5" to the riser at the top of the basement stairs.  If that is the case, that shouldn't be done.


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## NJDave (Sep 7, 2013)

To be more clear, we won't change the height of the top riser.  There's a "landing" at the top of the stairs and we will not raise the height of the landing but will be raising the height of the hallway floor on the other side of the door.  The threshold is between the floor in the hallway and the landing.


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## ICE (Sep 7, 2013)

That you can do.  The difference in floor heights will be a step.  There is no minimum step height and the maximum is 7.75"

That's IRC code.


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## fatboy (Sep 7, 2013)

I agree with the cold one.........

But it is not a good design to have a "step" in the doorway.

Welcome to the Forum!


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## ICE (Sep 7, 2013)

I agree with the corpulent one.....And no fatboy, that's not a military rank.


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## Rider Rick (Sep 7, 2013)

So you go up the stairs to the landing and trip as you go through the door. Sounds like a harry home owner design, to me.


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## ICE (Sep 7, 2013)

Rider Rick said:
			
		

> So you go up the stairs to the landing and trip as you go through the door. Sounds like a harry home owner design, to me.


Or you are headed to the basement and step wrong because you don't expect a drop.  Tumbling down the stairs you tear your meniscus.  On your fourth trip to the doctor's office, you are T-boned by a school bus. Ya see Dave, this stuff can be deadly.


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## cda (Sep 7, 2013)

Is tapering the end legal??


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## NJDave (Sep 7, 2013)

Rider Rick said:
			
		

> So you go up the stairs to the landing and trip as you go through the door. Sounds like a harry home owner design, to me.


Actually the project was designed by a structural engineer.  The design seemed like the least bad of a number of bad options.

I suppose we could remove the entire staircase to the basement and raise it 2.5" but that would be far too expensive.


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## Rider Rick (Sep 7, 2013)

NJDave said:
			
		

> Actually the project was designed by a structural engineer.  The design seemed like the least bad of a number of bad options.   I suppose we could remove the entire staircase to the basement and raise it 2.5" but that would be far too expensive.


As they say it cheaper to do it right the first time.

I would think the problem is having an engineer doing an architect's or DP job.


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## ICE (Sep 7, 2013)

Rider Rick said:
			
		

> As they say it cheaper to do it right the first time.I would think the problem is having an engineer doing an architect's or DP job.


This is a carpenters job.  There is the potential for a structural engineer to land the work but an architect wouldn't be able to keep a straight face.


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## mtlogcabin (Sep 8, 2013)

How long is the landing? Can it be sloped so the difference in elevation isn't as noticeable and eliminate the 2-1/2" step?


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## ICE (Sep 8, 2013)

mtlogcabin said:
			
		

> How long is the landing? Can it be sloped so the difference in elevation isn't as noticeable and eliminate the 2-1/2" step?


That might work as long as you keep the dogs balls off the landing.


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## Rider Rick (Sep 8, 2013)

ICE said:
			
		

> That might work as long as you keep the dogs balls off the landing.


Tiger,

Or you could get a girl dog.


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## NJDave (Sep 8, 2013)

mtlogcabin said:
			
		

> How long is the landing? Can it be sloped so the difference in elevation isn't as noticeable and eliminate the 2-1/2" step?


Yeah, I think that's about all that can be done is make it less noticeable with a saddle that is tapered.


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## ICE (Sep 8, 2013)

Mtlogcabin's idea is to eliminate most, if not all, of the step.  Leaving the step and making it less noticeable may not be the way to go.  Assuming a 3' landing gives a 13/16" slope per foot if the entire 2.5" is to be eliminated.  That might be worse than the step but then I haven't encountered such a landing so what do I know.

I would leave the step.  Most people are a little bit more careful when using basement stairs.  Trolls hang out in basements so we are always prepared to flee.


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## mtlogcabin (Sep 8, 2013)

That is a 5 to 6 percent slope. I believe under the IBC an existing building can have a 12% slope if it is not more than a 6" rise. There are ways to eliminate the step but what will be the safest for the occupants/users may need to have some careful thoughts, Age, physical limitations, how often will the basement be accessed are just a few thoughts.

We have a 10% short slope in our office hall. It is no problem for those of us that use it everyday. However I have seen and heard visitors taken by surprise at the sudden and abrupt change of elevation it creates. No trips or falls (yet) but it does not feel natural and can break up a stride


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## MtnArch (Sep 9, 2013)

Couldn't you just overframe the landing and stairs - that way you're not removing the existing framing and you're eliminating the engineer's trip hazard.  A little extra material, a little extra labor ....


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## Francis Vineyard (Sep 9, 2013)

Landings shall be level or sloped no steeper than 2-percent.

Francis


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