I have appropriately sized an LVL to extend a span by 3ft as well as assured the column support to the foundation at the new column.
EDIT: The existing 12 ft span is carried by a 4x10, the new span is 15 ft and would be carried with the appropriate full-length LVL
The existing simple span is a 4x10 beam with 2x8 ceiling joists. It had been my intention to build the temporary support walls, remove the existing beam, place the new LVL beam and re-hang the joists.
A competent framer told me that I could save work by setting the new LVL on top of the old beam then connect them with metal fasteners. In this way, I would only need to hang a few additional rafters from the new beam and would not need to build temporary walls or remove the existing beam.
The LVL is oversized so the additional weight of the 4x10 is negligible.
This method stands to reason in my mind and I would likely add some timber to keep the beam from yaw/roll anyhow.
Is this a common/acceptable practice? It seems perfectly plausible to me but I had never heard of doing this before.