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walkereng
walkereng, Consultant
Category: Structural Engineering
Satisfied Customers: 2701
Experience:  Over 30 years of Structural Engineering experience.
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Am using A36 steel beam to span a 27 feet wall that i just

Customer Question

am using A36 steel beam to span a 27 feet wall that i just removed.
live load = 100psf, dead load = 25 psf, roof joist is W2x10 running perpendicular to the removed wall or proposed beam
Submitted: 1 year ago.
Category: Structural Engineering
Expert:  walkereng replied 1 year ago.
Do you have any sketches or pictures you could share with me?
You can attach them to the Chat Window with the paperclip in the toolbar.
Customer: replied 1 year ago.
NO. the removed 27 feet is only a section of the wall. wall still exist on both sides of the proposed beam. the ballast roof is flat and covered with about 1/2 each thick gravel
Customer: replied 1 year ago.
am waiting for your answer
Expert:  walkereng replied 1 year ago.
OK, I have a few questions:
1. what is the span of the flat roof rafters off of each side of the proposed 27' span beam?
2. How did you determine the 100 psf Live Load and 25 psf Dead Load?
Customer: replied 1 year ago.
i don't want to call. that is too expensive
Expert:  walkereng replied 1 year ago.
I did not propose a call?
I asked you two questions above that I need answered so I can size the beam for you.
Customer: replied 1 year ago.
1. no rafter, it is w2x10 24 inches o/c
2. from original design, sorry dead load is 50 psf, not 25 psf
Customer: replied 1 year ago.
snow load is 30 psf
Customer: replied 1 year ago.
roof joist W2x10 @ 24 inches o/c
Customer: replied 1 year ago.
That is all the info
Customer: replied 1 year ago.
thanks
am waiting
Customer: replied 1 year ago.
i hope you got my answers
Expert:  walkereng replied 1 year ago.
1. OK, the W2x10's are spaced at 24" o.c., how far do they span off of each side of the proposed beam?
2. Is the 30 psf snow load in addition to the 100 psf LIve Load or is it included in it?
3. Do you have any beam depth limitations?
Customer: replied 1 year ago.
about 9 feet on one side and 14 feet on the other side
Customer: replied 1 year ago.
30 psf is in addition to 100 psf
Customer: replied 1 year ago.
no depth limitation but keep the depth as shallow as possible
Expert:  walkereng replied 1 year ago.
I’d like to point out that a Professional Engineer’s standard of care typically includes a site visit to assess field conditions and get an overall understanding of the structure. This can obviously not be accomplished through the internet. The information provided here is meant for planning purposes only (general sizing and budgeting) and is based on the information provided by you. All loading cases considered are for vertical loads only, no lateral analysis has been completed. The information should be verified by a professional engineer who can visit the site to ensure that potentially important information has not been overlooked or omitted.
Let me run a few numbers for you, I will be right back.
Customer: replied 1 year ago.
Am a P. E.
Expert:  walkereng replied 1 year ago.
You can use a W12x87 (36 ksi) steel beam for your 27' clear span roof beam. The beam is 12.125” wide and 12.5” deep. It weighs 87 pounds per foot of beam length.
You will need to have a local engineer detail your connections, size your support columns and determine foundation requirements.
If you feel you have received a satisfactory answer to your question, click the Rating button that is appropriate. Experts are credited for each adequately Rated answer they provide. If you have additional questions, please let me know. Thanks
Expert:  walkereng replied 1 year ago.
Let me know if you have any more questions
Customer: replied 1 year ago.
i need you to specify or design the support and connection
Customer: replied 1 year ago.
can the beam be supported by the remaining part of the wall on both sides
Expert:  walkereng replied 1 year ago.
No, the end reactions of the 27' span beam with a 130 psf Live load and a 50 psf Dead Load are on the order of 30,000 lbs at each end.
Specifying and designing the supports and connections is beyond the capabilities of this forum.
Customer: replied 1 year ago.
can you propose a beam with less weight 87 pounds per foot is too heavy
Customer: replied 1 year ago.
ok reduce the live load and snow load to a total of 100 psf. may be that will be less heavy
Expert:  walkereng replied 1 year ago.
That would give you a lighter beam, but you need to size the beam for the actual loads the Building Code requires. You can not just reduce the loads because you want a lighter beam.
Expert:  walkereng replied 1 year ago.
It is almost 1 a.m. here, could we finish this question in the morning?
Expert:  walkereng replied 1 year ago.
Let me know when you come back online

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