Important to note: you really, seriously, don’t need the extra strength the bottom piece gives. It is simply a complete and utter waste of oldgrowth forrests to strive for that quality. Loadbearing posts and beams are made in quality assured, tested wood.
Often times, like 99% of the time, the dimensions of the wood isn’t determined by the strength required, but rather the insulation thickness required, size of internal installations like HVAC, or soundproofing requirements.
2x4s are fine for up to 2 story houses where I live, so you either use 2x6 to get the r20, or a slightly better option. Still use 2x4, but clad it in rigid insulation to go from r12 to r20. This removes issues like thermal bridging and moisture penetration. But costs more and takes longer to do as well.
Important to note: you really, seriously, don’t need the extra strength the bottom piece gives. It is simply a complete and utter waste of oldgrowth forrests to strive for that quality. Loadbearing posts and beams are made in quality assured, tested wood.
Often times, like 99% of the time, the dimensions of the wood isn’t determined by the strength required, but rather the insulation thickness required, size of internal installations like HVAC, or soundproofing requirements.
2x4s are fine for up to 2 story houses where I live, so you either use 2x6 to get the r20, or a slightly better option. Still use 2x4, but clad it in rigid insulation to go from r12 to r20. This removes issues like thermal bridging and moisture penetration. But costs more and takes longer to do as well.