Taking the Twist out of a Steel Ibeam

[Mike I]

Hi,

I have a two-and-a-half storey house built in 1936. A steel ibeam runs east-west the length of the house in the middle of the basement, a span of about 30 feet. Its web is 9.875” and its flange 5.875”. It's somewhere between 10w22 and 10w12. There is one post supporting the beam at a distance of 5' 8” from the east wall. The span between the post and the west wall is about 22.5'.

The beam twists downward towards the centre of the 22.5' span and also sags about 5/8”. The total drop at the lower edge of the bottom flange is about 1”. The joists to the south are resting inside the web on the lower flange. Those to the north have lifted off it. They are floating above it, cantilevered on a partition located about 3' to the north of the beam.

I'm wondering if I can straighten out the twist in the beam by putting a permanent jack post under it and slowly raising it up. Will I be able to take the twist out at the same time as I get rid of the sag?

I'd be very thankful for any opinion or advice.

Mike.

 

[JohnKay]

Hi Mike
I can't see any way you're going to get a bend out of a steel, and it would be likely that even more damage could result from the force used. There's surely more load on this than just the floor. I really think the best course of action would be to get a structural engineer to take a look at this.

 

[Mike I]

Thanks, John.

 

[Lostvalleyguy]

Unfortunately you probably need to do more than just get rid of the sag in the beam. For some reason the load on it is more than it can withstand. You probably need a sturdier beam, a central support, or multiple beams to hold up the load safely. John is correct, contact an engineer. I wouldn't wait too long on this either as other problems may result or it may begin to get worse more rapidly due to the deformation.