Weight bearing beams

[abba]

I must span 15' of an outside wall to join finished porch and inside room.

The 15' beam must support outside weight of second story of home.

How may I compute the weight-bearing specs?

[giddonah]

By calling an engineer. This isn't something you want to mess up, and you'd be hard pressed to find anyone here willing to go out on a limb to tell you. There are span tables for loads, but this doesn't sound like a standard situation. The cost of someone knowledgeable to come actually look at it will be worth it.

[Cole]

I agree.

[giddonah]

also, the nice thing about having an engineer involved is that you have some recourse if something does happen. If you break your own house, you're pretty screwed.

sorry to turn you away on this one, please come back with any other questions.

[montytx]

Ditto with the above. I specialize in old houses and see it all the time. People covert an attic or add a load above a space and dont add the appropriate beams or load distribution. You would be suprised how bad the house looks in 20 years.