I am making a tiered - filled cake. I made a dam and even put a thin layer of icing down - to avoid seeping. I read that some people then put weight on it and let it settle in the fridge for a couple of hours. If I skip this step, am I going to be in trouble?
I don't do anything like that and my cakes don't slip or bulge. Others will post here that they never skip that step. I guess it depends on your confidence in the stiffened dam you made and your ability to dowel your cakes properly so that none of the cakes bear the weight of the cakes above them. Cakes don't just deflate and lose overall height by just sitting there with buttercream on them, or fondant for that matter - if you use high quality fondant, roll you fondant properly and use a thin (1/8th inch) layer of it.
The only real trouble you can get in is the dreaded bulge that can appear about two hours after frosting your cake. Every cake settles due to gravity and how the filling distributes after the top layer is applied. It can settle down as much as a full inch depending on your filling. Also, if you are starting with cake that is not already at room temp, as it comes to room temp gas, created by the cake coming to room temp, escapes between the layers and can cause a blow out...literally part of your frosting being blown away from the side of your cake. So it really depends on your icing treatment...if you are doing some sort of swirly pattern where the two layers meet then chances are you won't even see a bulge should it appear..or if you are already starting out with a room temp cake then you may not ever have a blow out. For me, I always start out with frozen cake that I fill and crumbcoat and then allow to come to room temp over several hours. On top of that my cakes are almost always covered in a final layer of fondant and a gas bubble or drooping fondant due to settling is just awful when you are trying for a pristine smooth finish....so worth waiting. The only times I've had issues is when I tried to rush the settling process. HTH. Cat