full width header and footer

I recently had a problem with page width on the Pinboard theme as i
wanted a page that was full width Keith Burgie here a member here was kind enough to help me and i did the following

#wrapper {
position: relative;
max-width: none;
margin: 0 auto;
box-shadow: 0 0 18px rgba(0, 0, 0, .4);
background: #f8f8f8;
overflow: hidden;
}

But my question now is how do i make just the header and the footer full width.

Im still using the pinboard theme