How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask StructuralEng Your Own Question
StructuralEng, Consultant
Category: Structural Engineering
Satisfied Customers: 7139
Experience:  Structural Engineer
Type Your Structural Engineering Question Here...
StructuralEng is online now
A new question is answered every 9 seconds

, I have a roof ridge that uses a perpendicular 2x4

Customer Question

Customer: ***** *****;
JA: Thanks. Can you give me any more details about your issue?
Customer: I have a roof ridge that uses a perpendicular 2x4 support and two supports off at an angle. They are close to each other at the bottom. I want to replace that with a if you hold up the three middle fingers of your hand and spread your fingers - it looks like that kind of a shape. I want to replace that support with a beam underneath which has a span of about 6'; it will open the area up instead of being blocked from bottom of attic floor to the top. An engr told be a 2x8 header two 2x8's with 1/2 material inbetween) But I want to use structural steel to make the height smaller
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $18) to post your type of question to Structural Engineering Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: Yes, but to make it simple if you can answer it; for a 6 foot span, can a steel I beam 3" height 5.7lbs per foot support the same weight as a 2x8 double header?
JA: OK. Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Structural Engineering
Expert:  StructuralEng replied 1 year ago.


Expert:  StructuralEng replied 1 year ago.

Do you have any pictures you can post?

Customer: replied 1 year ago.
support_1.png is a picture to show the three supports that I hate
support_2.png is a drawn over picture to show the support beam position
ridge Support is picture of what structural engr sent mebut I need 6' and I want to reduce the height
because the height of available space allows me more room to position duct pipe for ac system
Im trying to get rid of the plenum boxes.
Customer: replied 1 year ago.
The other side of the ridge board doesnt go very far back and the side rafters are relatively short in length
ridge board goes about 4' on other side of 2x4 support.
Customer: replied 1 year ago.
the ridge is sitting at about 18" to 24" from one end
so the load is not in the middle of the span
Expert:  StructuralEng replied 1 year ago.

Thank you for the attachments

Customer: replied 1 year ago.
I was looking at this web site for structural steel bottom of attached pic
B1357 is 3" high I beam with 5.7lbs metal per linear foot
B1477 is 4" high I beam with 7.7lbs metal per footWhat kind of steel I beam can replace the load capibilities of a double 2x8 header support beam like in the Engineer's drawing I provided earlierthanks a lotDennis
Expert:  StructuralEng replied 1 year ago.

I would use W4x13 so that lateral torsional buckling is not a concern.

Expert:  StructuralEng replied 1 year ago.

Hello. Do you have any other questions for me on this topic? If you could rate my answer, I would appreciate it.

Related Structural Engineering Questions