Connecting shower waste to bath waste

[petanck]

Our master bathroom has both a bath and a shower next to each other along one wall with the waste stack in the corner on the opposite side. This means the bath waste run is about 2m but the shower run is nearer 3m (has to run down the length of 2 walls). This means the shower waste is very shallow and does not drain out of the shower very well. I want to take out the shower base, build a platform to increase the height and so improve the drop.

My question is, can I join the shower waste to the bath waste so down the last wall I only have 1 waste pipe running, rather that the two that are there at the moment? If I can join them together, are there any things I should consider in how to go about this?

[IJWS15]

Depends on whether you want the bathwater to come up out of the shower drain and run all over the floor when you pull the plug out of a full bath!