Expert: Dave Johnson - 11/13/2008

Question
QUESTION: Hi - we are currently undergoing renos.  We have hired a contractor and he has torn down a supporting wall on our main floor and put up a beam.  A few hiccups - first, he ordered a steel beam, but cut it too short.  So then he brought in a wood beam and put it up (demo was Monday, wood beam went up Tuesday, and dry wall/mudding started today, Wednesay).  My question to him this morning was about the cost of our addition - we plan to build a second story on top of our small bungalow.  He was surprised that we planned to expand over the whole house - apprently thought we only wanted to expand over the garage - so anyway, told me he wasn't sure the wood beam would support the weight of a whole second story and would have to look into it.  My reaction, I was upset of course, because the steel beam is smaller in size, would have less of a bulk head, and it was his mistake cutting it too short...I was angry because I thought his job as a contractor would be to ensure the beam is strong enough to support our plans - this is a thought that wouldn't occur to me on my own.  So I asked him to stop until he knew if the beam would support the addition or not (because why pay for this job and then pay again later for someone to fix the beam so it will hold the load, why not just do it right the first time) - but I went to work, and when I came up, the beam is up, and drywall and mudding is done around it (first coat anyway).

So my question - will the wood beam be strong enough to support a second story addition?  And, are we being taken for a ride by this guy?

Your feedback is much appreciated!

Thanks,
Melissa

ANSWER: Hi Melissa,
First, I would need to know the span (length) of the beam and the size (height and width)

Is this an exterior wall?  an interior wall?

If it is an interior wall, the beam needs to support only the new live weight of the occupants and furniture. There will be no weight from the 2nd storey if he uses clear span trusses ( all the load will be on the exterior walls)

Please mail me back with more info, glad to help!!

Dave

---------- FOLLOW-UP ----------

QUESTION: Thanks for your prompt response.  To answer your questions:

It is a 20 foot beam (20'L x 12"H x 6"W - this is measuring through drywall though.  I noticed when he put it up, there are 3 smaller separate wood beams (same L and H, but maybe about 2" W and then nailed together).

It is an interior wall - and I don't know what you mean by clear span trusses, but if that's what they are (and I can ask) that would be promising.  We haven't done the 2nd story addition yet, but we want to - we just don't want to have to pay for another support beam to be put in, when it should have been done already...anyway, hope those measurements/info help to answer your questions...and thanks again for your feedback!

Melissa

Answer
Hi Again,
He has used (3) 2"x12" laminated together for the beam, this is actually stronger than a solid wood beam of the same size.
Using this. you may experience some "bounce" when the 2nd storey is added. It will not collapse, but a stronger beam would be better. If he will do it, there should be another 2"x12" on either side of the beam just installed, well nailed or screwed!

The clear span trusses means they are supported on only the exterior walls, adding no weight to any interior floors/walls.

It would be in your best interest to have him add the extra, better now than be sorry later!!

Best of luck, Dave