header beam load capacity

[Boxerider]

Ok, techically not a garage question, but there seems to be people here that might be able to help.

My porch roof is supported by a 4x12, spanning 21 feet, with two 4x6 posts at 7 foot intervals. I would like to remove those, and place the posts at the ends, to open up the porch. It is a solid wood beam, not an laminate.

Does this seem unreasonable? Possibly useful info is that I have the addition plans for the porch roof, and I *think* the posts were placed where they are because the original drawings called for glass in the two flanking openings, and a door in the center, like a sun room. That having never been done, I want to open the whole thing up.

 

[ddawg16]

You will need to replace that beam with a LVL or PSL beam. According to my span tables, the max span for a 4x12 is 16'.

For reference, the beam in my garage spans 20'...it's a 16"x7" PSL

And for those end posts....you need to make sure you have enough concrete/footing underneath to support it. But chances are ok in that part.

 

[Boxerider]

thanks, I was having a hard time with span tables on the net. But thata would seem to indicate I could move the posts out, to create a 16 foot center and 2 smaller end openings? or leave the one by the bush and move the other one to the end?

either way, I will cut the porch and pour a footing. the company that built this place in 89 would certianly have pouredd the porch thin. they are "that" company.

replacing the beam is out of the question, this is either a cheap little tweak, or it isnt happening. its really not a big deal except that post is in the middle of a nice view.

 

[Cyberbear]

Check with your building dept., but back in the day a 4 x 12 header was good for a 12 foot span. It may be good for a longer span w/o a load to carry.

 

[bigdav160]

I bet those post can come out with no problem.
However, we don't know where you live or the type of wood the beam is made from.