Wooden stairs with handrail dead load

[Cassidy G]

Good day, Engineers.

I'm design a 2 storey residential house. It has wooden stairs. Only a Draftsman draw the architectural plan and not an Architect.

I ask the draftman what kind of wooden stairs it is, for me to know or search the weight of it.

He replied, (Don't think about the weight of the stairs, it is made of wood. You can excluded it in your design.) hahahaha.

He is 58yrs old man, feeling know everything. Waiting for his retirement.

We always argue about his drawings. So I don't ask him anymore. I ask the client but the client keep telling me that I should ask the draftsman.

Anyone can give an idea what is the assume for the weight of wooden staits with handrails. Any link.


Thank you.

 

[Agent666]

Use your judgement here, you are an engineer after all. There is no right or wrong answer here.

It depends on the material, type of construction, so work out what you need structurally, work out the weight of this, and apply some superimposed load allowance for architectural rubbish. If there is uncertainty, use a conservative number. If there is uncertainty put your design assumptions regarding load/material on the drawings.

 

[Cassidy G]

Good day, Engr. Agent666.

Yes, I have the computed weight already base on my judgement.

I just want a second opinion or any advice.

Thank you.

 

[hotmailbox]

How couldn't you estimate the weight of the wooden stair yourself? You don't know what it is made of?

 

[jimstructures]

Cassidy G,

How hard can this be? You know the size of the treads, risers & stringers. You know the species of the wood that makes them up. Therefore you know the density of the wood. Therefore you know the weight per step. Count the steps. Multiply the number of steps times the weight per step, add 10% and you have the dead load of the steps or a reasonable approximation thereof. Maybe add some drywall weight in as well.

That should give you a reasonable approximation.

Maybe I don't understand something in the question.

Jim

 

[Cassidy G]

Hi, Sir hotmailbox and Sir jimstructures.

I only have floor plan and the stairs has no details, no section views, no sizes, etc.

Like I have said, I tried to ask the draftsman, he said "it is only a wooden stairs don't mind it. Design the concrete frame only."

Last time I ask him what kind of floor finish, he replied. "It is granite marble, don't mind it. Structural Engineers don't consider it, just design the concrete frame."

LOL

And that's when our fight started.

No Engineers will believe this kind of draftsman.

Afted that I made a call to my boss. I ask what kind of floor finish it is, because it is not indicate in the plan. He said ceramic tile.

 

[Cassidy G]

You're right Engineers. This is a very easy calculation.

But knowing only the density of the wood and not the sections, sizes of treads, handrail, etc. is very hard to imagine.

Thank you.

 

[hotmailbox]

If this is just a wooden stair in concrete structure, I think the draftman is correct. You're the engineer, you tell him the size of the treads, (make rough estimate of handrails but this is too small to care). The only thing you need from the architect is what the finish material of the treads is (wood or stones or something heavy).

If you have to design the stair then use 40psf dead load & 100psf live load (way conservative). To design the concrete frame, use the same loading and multiply it with tributary width.

 

[Cassidy G]

Nope, Sir hotmailbox, he is the draftsman and feeling architect.

I'm the engineer here and don't have the power to tell the size if treads. That is true.

Because of ego. I'm 27yrs old and he is 58yrs old.

But no age for professional. That's why I laugh hard hahaha.

He acts like a boss hahaha.

 

[Cassidy G]

Engr hotmailbox.

By the way, do you have reference code or book for the 40psf dead load and 100psf live load.

Thank you.

 

[BAretired]

Ha ha ha!

BA

 

[hotmailbox]

Sorry I can't help you any further.

 

[jimstructures]

Cassidy G,

If you are designing in the United States or using US based codes & standards you should use the appropriate version of ASCE 7 / xx for the recommended Dead Load and Live Load. Check with the local Authorities Having Jurisdiction. You have not stated the location or the Code you are using.


Jim

 

[Cassidy G]

Engr jimstructures and hotmail box.

I used NSCP 2015, our code has no live load for stairs. Some designers here only used live load of occupancy which they are associated.

Yes I check the ASCE and IBC before.

ASCE/SEI 7 (ASCE 2016) has dead load for stairs.

IBC live load
Handrail 50lb/ft
Stair tread and landing 100psf.

I'm thinking if that 100psf live load is applicable for 2 storey residential house. Or it is only for public assembly building.

Thank you.

 

[jimstructures]

Cassidy G,

I am not familiar with NSCP code. What is the acronym short for?

Jim

 

[Cassidy G]

jimstructures

National Structural Code of the Philippines.

At ASCE and IBC, stairs tread and landing live load is 100psf. Is this for public assembly building or it is also for residential house?

 

[jayrod12]

Public assembly. Residential stairs serving a single unit can be designed for the same loads as the unit floors itself.