On this template I’ve built using Foundation, everything looks correct and responsive except for both navigation bars. They’re both on their own <div class="row">, yet they overlap eachother on window resize.
(There is a @media only screen and (max-width: 767px) that is supposed to make it look even cleaner, if it helps at all).
Actually if you open the page on chrome with the developer tools or in firefox with firebug, you can see that when you make the page smaller than 767px width, is when the problems enters, due your @media only screen and (max-width: 767px). i would recommend to check that css cause if you removed it from the html you get a better result, so you may check what attributes inside that css are making your div crazy.