I have a huge problem with this. My cakes always start to bulge out from the sides in between the layers. I hate that so much. I always press down after stacking and create a dam with my thick consistency butter cream. I frost as smooth as possible and my layers are leveled perfectly. What can I do different???? 

AMaybe cut more of the top round off?

http://cakecentral.com/t/633571/my-newest-trick

I would suggest that after you frost the cake, let it set up in the fridge for hours. Sometimes, I let it sit overnight. Then, apply a second coat of buttercream and then back in the fridge for a few hours. Then another layer and the fridge again. Then I cover it in marshmallow fondant and send it back into the fridge. I know it's time consuming but for me, that's how I get the perfect 90 degree sides and no bulging. For my square cakes, I do even more layers. It builds a strong side. I hope that helps!

Jennifer

FYI, cake can't settle in the fridge.

Ya know what happens to 3+ more layers of BC and MMF when it comes to room temp for serving?

I should clarify. Three THIN coats of buttercream. First is the crumb coat (and for mine, I still have some cake exposed because in this stage, I want to make sure my dams are holding in the filling), the second coat covers the whole cake so that no cake is exposed. The third coat covers the cake evenly. (I sometimes do a 4th coat to get it perfectly smooth with my straightedge and then I cover with a thin layer of buttercream. I've never a problem with there being too much buttercream on the cake so when it comes to room temp, no issues :) I've attached a picture of cakes I had in the fridge last summer that just happened to be coated differently! Then, you can see the finished product of a slice of cake at room temp :)

As a side note, if I'm not using filling in between the layers of cake, I only do 2 coats and make sure to get the straightedge out for the second coat. In between the coats of buttercream, I refrigerate for a few hours though to make sure the buttercream really crusts over.

I hope the visual helps! :)

Jennifer

thanks alot for your help i will give it a try!

Try using ganache as a crumb coat.  I had the same problem, and read a thread on here (something about never using buttercream again...), my problem is solved.  The ganache keeps the filling in place and works great!  Hope this helps!

AAgree with tjgett...best move I've made was from buttercream to ganache coating.