# Is it possible to extend an I beam (RSJ)



## drjarmin (Jan 17, 2011)

I have an internal wall which is a supporting wall which 2 years ago I had a ~10 foot entrance way knocked through to joint 2 rooms.

The contractor supported the upper floor using a steel I beam (RSJ).

I would like to make this gap wider, but obviously would require a longer piece of steel.

Do I have to replace the existing joist or can it be lengthened by welding and / or bolting a new I beam to extend it?

I am in NO WAY planning to undertake this work myself, but am in the planning stages and trying to figure out what is feasible.

thanks!


----------



## fabricator (Jan 15, 2011)

Yes it is possible providing that it can still handle the load. As a 20 year welder /fabricator I would prefer welding mainly because it is quicker and less work but bolting the two is just as effective. Either way you would need two plates about 10 inches long and wide enough to fit on both sides of the webbing between the two flanges.
Butt the new beam up to the existing one and put the plate on each side and then it can be welded or bolted (or even both). If bolted then I would go with a minimun of three 5/8 bolts on each end of the beam (just a guess since you give no size or length of beam.)


----------



## drjarmin (Jan 17, 2011)

Thanks, it was just an idea and I wanted to see if it was a possibilty.

The beam is around 8 - 10" long and 1' high. Would be a lot of work to replace it. I want to 'move' the gap - ie put in more supports for the first 2 - 3 foot at one end, and knock down more wall the other end and bolt / weld an extension to it.

Next, need to figure out if it can take the load....


----------



## Daniel Holzman (Mar 10, 2009)

Are you certain that beam is 8 - 10" long, not 8 - 10 feet long? And a foot deep sounds excessive for such a short span in a W or S shape, unless the fabricator installed an oversized beam or you have very heavy loads above.

As to welding or bolting on a section, yes that can be done, you do have to be careful to use an adequately long plate to connect the new to the old, as discussed in the previous post. If access is a problem, welding may be difficult, and bolting could be easier. You do need to make exact measurements so you can determine exactly which shape you have, then you can determine if the beam is adequately sized. Remember that a longer beam is going to experience significantly higher bending stresses, so would typically need a deeper or heavier beam section.


----------



## fabricator (Jan 15, 2011)

Also if you really want to make sure it will support the load you can add flat plate all the way from end to end on both sides of the webbing instead of where the joint will be. Example; 10 inches heigh x 1/4 inch thick x 12 feet in length.


----------



## Anti-wingnut (Oct 18, 2009)

Remember that an engineer should design this beam and it's connections. Bolting using a gusset on the webs may be possible, but a connection involving the flanges is more likely.

The possibility of welding is dependant on the type of weld specified. If certified full penetration welds are required, it may be more cost effective to replace the beam.

Welding in a wood framed buildiung can also be a fire hazard


----------



## drjarmin (Jan 17, 2011)

Thanks everyone. Yes, I mean't feet not inches!!! Whoops.

The current gap is 11'8". I want to extend it by 3 feet to 18' but I am happy to put addition pillars, supports for the first 4' of the existing beam so the total gap (ie span between supports) will be 14' (hope I am explaining it well - my plan is to extend the gap, but also to move it 4' to the right).

I have attached a picture. The plan is to remove the red grid part of the wall, but to add additional support (maybe some steel posts?) where the 2 big red rectangles are (if necessary to reduce the span from 18' to 14').

This is in the ground floor of a concrete construction house.

The existing beam is around 12 - 14" in height (can't measure as it is boxed in. It is higher than the beam in the picture suggests as there is a false ceiling).

Thoughts anyone?

Thanks.


----------



## fabricator (Jan 15, 2011)

Picture???


----------



## drjarmin (Jan 17, 2011)

Ooops!!!

Thanks - attached.


----------



## Anti-wingnut (Oct 18, 2009)

I think it would be unnecessary to add columns on the left hand side. And it certainly looks possible to remove and replace or add to the existing steel. 

An engineer will be needed to tell you the size (depth and width/weight per foot), web stiffeners and welding requirements. They will also tell you if you need to add to the existing footing on the left, and what is needed on the right. This is because you have added (however minor) to the existing point load on the left. The right hand bearing wall will be replaced by a point load. This will probably result in you needing to do a saw cut in the floor and add a footing. The engineer will also detail the attachment of the wood joists to the new steel.

I would guess that almost invariably you will replace the entire steel beam with new.

But I want to stress that my opinions are only that, and you should follow the guidance of an PE.


----------



## Anti-wingnut (Oct 18, 2009)

Also, don't think anybody is stupid if they don't know what a RSJ is. I've worked with steel for almost 30 years and had to Wiki it up.

Some engineers are going to try to muddy things up also, by using HSS as alternately "high strength steel" and "hollow structural shape" ( round, mechanical, or square tubing and pipe)


----------



## WillK (Aug 29, 2010)

I'd question weather welding would be any better for cost than complete replacement because I would think it best to remove the beam to weld more length on anyway due to the fire hazards of the temperatures reached with welding in the presence of wood frame.


----------

