Extending an RSJ ?

[pyramids.of.mars]

Hi All

The following is nothing more than a theoretical idea at this stage. I'll not be doing any of the work myself, I simply want to gain a little knowledge before discussing with a builder :-

Could an installed ~5ft RSJ be extended by joining it to another 4 ft section ? Is welding two RSJs acceptable ? Are there other approved methods of joining that don't compromise rigidity ?

The objective is to remove a supporting pillar to create an open-plan room by extending the beam to reach an external wall for support.

I'm assuming that this approach would be cheaper and less disruptive than ripping out the existing beam and replacing it with a 9 footer.

Paradoxically, the upper wall that the RSJ currently supports will be removed during the project, leaving (relatively) little weight on the extended beam. However, an extended beam would greatly assist the rearrangement of the floor joists above, which is necessary to remove an unrelated load-bearing internal wall.

Cheers, GD

[fred]

In article , [e-mail] writes

The load bearing capacity of a single 9' beam can be certified by the manufacturer but the quality of the welded composite cannot. The disruption caused by the replacement of the 5' by the 9' is really not that great and the peace of mind gained by that solution really makes it a no brainer, replace in the whole. Steel is (relatively) cheap.

[Roger]

The message from fred contains these words:

And the discarded beam will probably have some residual value.

As the wall above is being removed the replacement should be relatively painless. Normally such an increase in span would require a deeper section beam but as the loading will be less you might get away with the same depth beam, but do check.

[dg]

I doubt if a weld to the join would be suffcient, and it would probably require two plates to be bolted or welded into the web.

dg

[The Natural Philosopher]

Seconded heartily.

If the wall above is going, ask an architect or structural engineer whether you need steel at all.

[Rick]

You can extend them, you bolt plates into the web. However the resultant RSJ and its use, and the way you extended it needs to have been caculated as approrpriate but an engineer.

Rick