I have a patio roof that is 24' long supported at each end and every 8' with a 4x4 post. I would like to remove one of the post's to create a roughly 16' space between the posts. The current beam support the 2x6' rafters is a double 2x4. What should I replace it with to support the 16' span? I live in western New York and the roof has a low pitch so snow of 12' on the roof are not unheard of. Thanks for any help you can give.

Sorry mistype in the above post. I meant snow loads of 12 inches.

Thanks againg

If I am reading correctly, u have 4 post now and want to remove one. Is this correct.

Any span that is more then 16 inches should have a header to support the rafters between posts.

On an 8 foot span would normally put a 2x10 header.

On a 16foot span a 2x12 header with a 3/4inches gusset between the 2x12's and 1/2 inch bolts in a zigzag patent 1 foot apart 2 inches from edge of 2x12.

These headers should be supported by double 2x4 or a full 4x4.

Chuck

You don't provide enough information to adequately answer the question.

We would also need to know the length of the rafters in order to calculate the loads on a 16 foot long header for at least a 30 psf localized snow load.

Generally speaking, however, not even a beam constructed of 4 2x12s could adequately span this 16 foot distance and support the loads at 40psf... the normal design load for deck joists.

Under 30psf load conditions, the maximum span you could achieve with 4 2x12s is less than 12 feet.

Your only recourse here is either an engineered LVL or steel girder, especially if your rafters are longer than say 8 feet.

I've attached a PDF with drawings that hopefully have enough information for you.

There is a proposal for modifications to the existing beam that I would input on.

Thanks again for your help.

Again, a beam constructed from 4 2 x12s might just barely adequately span 11' 6" given the snow loads, but not the beam design you have proposed.



Consider instead an engineered LVL which could sized vertically smaller than a 2x12 beam and still handle the load.