Will It Stop?

I sometimes wonder how I am going to stop the feud between my daughter and my husband. My dh is her step father and she accepts him, but she is 18, very outspoken and has attitudes once in awhile that leads into fights with him. My dh can't stand that and gets angry. Sometimes he will say hurtful things like shut up, etc. He also has different views then I do and if it isn't done his way then that leads into fights. My dh and her get into just about every day and I am to the point where I don't know what to do about it. I feel like I am getting dragged in the middle of it, caught between both of them. I love my daughter very much as I do my dh, but if I take my daughters side my dh gets mad and if I take his side my daughter gets mad. 

I have tried talking to my dh but he want listen to me always saying that I am taking her side, which I'm not unless I feel he has done wrong. I told myself that maybe I need to just keep my mouth shut and stay out of it. But she is my dauther, so it isn't that easy.  Grant it my daughter is wrong with her attitudes and the way she talks to him or us, but he is in the wrong too sometimes.  I feel like I am caught in between a rock and a hardplace.  It also breaks my heart, bc the more he acts this way the more I am disapointed in him and losing my respect.   I just wish I could snap my fingers and everything will be okay, because I honestly don't know how much of this I can take. Just like I have always told him and her enough is enough. Something has to give, or steps has to be taken to end it.   The question is when or what?