really need to make sure you have a proper BB for a triple as the width needs to be correct or you'll face chain-line issues.

Shimano 105 BB5500 68x109 5mm English V1 Spline BB | eBay
is not the same as
Shimano 105 BB5500 68x118 5mm English V1 Spline BB | eBay

The 109.5mm is for a double and the 118.5mm is for a triple.

I'm using the 5500 as the example as that's what I've got on both my triples, but I think the same width principle applies int he Ultegra group..