Sistering Wood Beam

[SteelPE]

I was recently called out to look at an issue a client found while renovating an old 1800’s era brownstone. During demolition of the existing partitions, the client hit an old column that appears to be holding up a header beam ( 5 ¼” x 11”) that frames around an old fireplace. This column ends up right in the location that they want to put their bathroom vanity. Simple solution, adjust the bathroom layout around the discovered column….. not with these clients, they want this vanity as designed no questions asked and the column must go.

I am not exactly sure why the column is there in the first place. It is obviously there to support the header beam which is 21” short of the existing bearing wall. Why didn’t they bear the beam on the wall to begin with….. I have no idea.

I am toying around with the idea of extending existing wood header the 21” to bear on the existing brick bearing wall by sistering steel channels (maybe some 8’ long 10” deep channels that overlap the existing wood beam a good 5’-0”-6'-0") that would be through bolted through the 5 ¼” x 11” wood beam. I am not exactly sure about the magnitude of the load we are dealing with…. But I am thinking we need to support about 3,000 lbs.

Does this solution seem feasible and are there any drawbacks?

 

[jerseyshore]

I've never been a fan of only doing a partial splice of a wood member, unless it was a one-off floor joist or something minor like that. I know some people do it, but I've never specified it for a beam. Anything that I am splicing/extending goes the full length for me when it comes to wood construction.

If you can run the channels back 5-6 ft, can't you just run them back the full length?

 

[BAretired]

Looks like a real can of worms. I don't understand what the original designer was thinking. The column is not vertical, and I don't see the 5¼”x11” header the column is allegedly supporting.

Fitting and connecting two 8'-0" long by 10" channels might be a little difficult, but if the contractor is happy with that solution, it should be fine. The moment connection between steel and wood requires special care.

 

[SteelPE]

The sloped column is supporting the 5 1/4" x 11" header in question which is above the column (you can see the end of the beam where the column bolts vertically into it). sorry, they were still demolishing members when I visited.

I'm not quite sure what was going on in this area and why the beam was left short. The column is obviously structural and in order for it to be removed we will need to do some sort of reinforcing in the area.

The contractor is proposing bolting a column to the wall with a moment connected outrigger to pick up the beam. I don't like this idea solely because it requires epoxy bolting of the column to the 100+ year old multiwythe brick wall. I would prefer to bear on the wall with the sister steel channels outlined above.

The existing 5 1/4" x 11" is approximately 16'-2" long where it bears on another multiwythe brick wall on the other end. I could potentially have the contractor increase the length of the channels to say 15' which would give an overlap of 13'-0" +/- with the existing 5 1/4" x 11". The new channels will not be able to bear on each end without some work needing to be done both above and below.

 

[BAretired]

and BA[/color]]The sloped column is supporting the 5 1/4" x 11" header in question which is above the column (you can see the end of the beam where the column bolts vertically into it). sorry, they were still demolishing members when I visited. I see the end of a member which looks about 5x11, but it doesn't seem to be heading toward the brick wall.

I'm not quite sure what was going on in this area and why the beam was left short. The column is obviously structural and in order for it to be removed we will need to do some sort of reinforcing in the area. Agreed.

The contractor is proposing bolting a column to the wall with a moment connected outrigger to pick up the beam. I don't like this idea solely because it requires epoxy bolting of the column to the 100+ year old multiwythe brick wall. I would prefer to bear on the wall with the sister steel channels outlined above. If the column is carrying 3,000#, the moment would be roughly 6'k, which is not large. An "L" shaped column and outrigger would not be relying on bolts to the existing wall for anything other than nominal lateral support. If the column projection is not in the way of the proposed vanity, I would check out the contractor's idea.

The existing 5 1/4" x 11" is approximately 16'-2" long where it bears on another multiwythe brick wall on the other end. I could potentially have the contractor increase the length of the channels to say 15' which would give an overlap of 13'-0" +/- with the existing 5 1/4" x 11". The new channels will not be able to bear on each end without some work needing to be done both above and below. I don't know whether it is necessary to extend the channels to 15'; for a moment of 6'k, an overlap of six feet requires reactions of a little more than 1000# which is not too onerous.

It may be best to check both proposals to see which is preferable.