You wouldn’t tend to add sleepers afterwards. Considering a sleeper wall is constructed, then S&C, then DPC then more S&C and then a section of 4” x 2” on its side which is then screwed/nailed into from the joists above- I can’t see how adding a sleeper wall would work easily after the joists are down.
Take noggins out and double up the 4 x 2. It’s fairly simple and cheap. Where are you getting timber from locally
That’s because they’re completely different products.
And have different functions.
Bps are great. Don’t use anyone else
Reply to the thread, titled "Suspended Timber Floor Tile Prep" which is posted in Canada Tile Advice on Tilers Forums.