I am removing a load bearing wall about 12 feet long , how tall and wide should the beam be?

Question

The house is only 1 floor and the beam will be supporting the ceiling rafters and part of the roof.

Answer 1

A doubled up 1-3/4" x 11-7/8" Microlam should be plenty, but check with your building inspector.  You will need a permit for this since you are altering the structure of the house, and your inspector will also tell you how many shoulders you will need on each end.  At 12', I would put 4 under each side, but check with the inspector for sure.  Good luck.

Answer 2

It depends what country you're in to a large extent.

Firstly you have to work out what loads the new beam will be carrying, so this involves a bit of maths and standard tables to calculate the weight carried by the beam, plus a safety factor. The weight carried by the beam depends on your geographical location (because of weight of snow on the roof etc.).  If ur stuck at this point call a structural engineer.

Some beams can be bought off the shelf, so give a manufacturer a call and tell them the loads that you worked out in part 1 above - in the UK companies like Catnic and Birtley have quite competent technical departments to help you choose the right beam.

If you go for a timber/glulam or RSJ (steel) then in some countries this size can be read off a table, in the UK unfortunately its down to the maths again so a structural engineer should be employed.

An engineer can also advise if the bearings for the beam (e.g. the bits of wall left that the beam sits on) are strong enough to provide adequate support.

Without knowing the exact situation I wouldnt even hazard a guess at the size of beam needed.  I wouldnt pay any attention to any answers that do give a guess, as none of them know what load the beam is taking

Answer 3

That depends on if you have a second story. Your local building code department should give you an answer. You can consult a structrual engineer but it will cost you. My guess is 6 x 12 but you'll need a permit so it would be wise to consult the local code inspector.

Answer 4

Are you in USA? Consider an average garage door span. The header for a 12' span would be 3 inches thick and 11 inches high. These days, codes required laminated headers, although standard lumber this size was always used in the past. Making headers is usually done with 2 pieces 1 1/2 inches thick doubled up.