Your navigation bar on your website is of utmost importance. It is the place most people will go to when looking for something on your site. It is often positioned along the top of the site so people can quickly go from page to page to find what they are looking for. Moving the navigation to a different position can be potentially damaging to your website visits as you may find that people struggle to know where to go on the site and end up leaving.
If you find you have far too many buttons that need to go on the navigation, rather than splitting it on to two lines which can look messy and may not display well on all devices, think about how you can group them. If you have a tab for each of your services, then see if you can split them into one or more group to shrink the space needed on the nav bar. It may be that some of your services are for businesses and other consumers. If this is the case then you may have the main business and consumer buttons with dropdowns for the services within those categories.
Having the navigation move down the page as you scroll can be another relatively simple but effective technique. It allows visitors to navigate quickly without having to keep scrolling back up. This is ideal for sites with longer pages.