Question: What is another way of saying, "raise the roof"? This slang phrase means something like, "get noisy and have a good time at a party," but it doesn't sound correct for some reasons. 

Why is that? What would be better?

Answer: 
You might [get down](http://en.wiktionary.org/wiki/get_down), especially if you plan to dance. Or, if you want to make a lot of noise, you might intend to [rock the house](http://en.wiktionary.org/wiki/rock_the_house). 

Slang terms for partying tend to change along with pop culture, which means that while suggesting you get [slizzard](http://slizzard.urbanup.com/5134275) now is popular due to recent mentions in music, it'll be uncool soon enough; calling something [crunk](http://onlineslangdictionary.com/meaning-of/crunk) probably sounds outdated; and suggesting you [get the party started](http://en.wikipedia.org/wiki/Get_the_Party_Started) might get you an eye-roll unless your friends are fans of Pink. 

If you're looking for something more timeless, try the simple version: *let's party!*
It seems "lame" because it's antiquated -- the only thing that spreads as quickly is slang is the knowledge that a slang term has become "uncool." 

"Raise the roof" is a dance move, usually used (the key word here is USED -- it's completely out of favor) in hip hop, in which you push the palm of your hands towards the ceiling as if you're raising and then lowering the roof over and over.

"Raise the roof" is also a phrase that expresses the sentiment that a group intends to "go out". It can also just be an expression of excitement. Depending on which meaning you're using, there are many ways to say it, and you probably don't need to use slang regardless of what group you're addressing. One alternative would be "Let's hit the club!"