Maximum allowed deflection on a 4x12 and 4x14 wood beam at 16'span 2

[nvhig1]

I need to have the maximum allowed deflection for a 4x 12 & 14 df wood beam with a snow load of 40lb and to be used as a garage door header. Any help will be appreciated.

John C

 

[boo1]

What is your tributary area?

 

[boo1]

for tributary area DaveViking recommended this website:

http://instruct1.cit.cornell.edu/courses/arch264/text/ch1statics/1.2.html

 

[RockEngineer]

If you really want the allowable deflection for your header your question has not yet been answered.

The allowable deflection is usually governed by one of two things, code or serviceability.

Most codes specify roof and floor deflections but they can also be applied to headers. Deflection is limited to L/240 for dead + Live load or L/360 for live load only (L is your 16 ft span).

Serviceability means will the header deflect so far it hits something else or causes problems. This depends on the type of garage door you have. Most 16 ft overhead track garage doors can withstand deflections 1/2" at the center of the header without bothering the door movement. L/360 and the 1/2" give about the same limit for a 16 ft door opening and is what I would use for a overhead track door.

All that is left is for you to calculate your header load and the deflection.

 

[boo1]

Nvhig1 additionall information is still required: span, tributary area, wood type, ceiling material (plaster, drywall, ect)

 

[nvhig1]

Thank you for all the information Boo1, I have learn a lot from this. I am not an engineer, I am a general contractor and needed some reference for a client that had this problem but I did not know how to go about getting it.

The web link for the tributary information and your comments have been extremely helpful and have given me the hope that there are some engineers that do know their stuff and that are not selfish and are willing to share the knowledge.

Thanks a bunch!

Sincerely

John Chavez