Warped top on a Guild D55

Q: I have a Guild D55 and have observed a slight rise on the top between the bridge and end of the guitar. What playing problems would this cause and how is this corrected? Thanks,

Randy

A: The top of a "flat top" guitar is not actually flat. On many guitars a slight arch is bent into the top as it is glued to the braces and the liner strips. During times of short humidity an arched top will flatten out, a flat top will crack. All guitar backs are arched.
Even tops that are built flat are not built rigid. The tension of the strings pulls them into an arch. People think of a guitar as rigid but it is really a spring system. When you take the strings off of a guitar the top flattens out and the neck bows backward. Part of the art of setting a comfortable action is to take this flex into account so that the string tension pulls everything straight.
Loose braces or a loose bridge will cause a top to belly up. Take a look inside your guitar with a mirror and a flashlight (I use a small 40 watt bulb). Push on the top and look for movement or gaps, and listen for squeaks. Check the bridge with your eyes or by trying to slide something thin under it. If you detect evil don't try to fix it yourself. Both jobs, braces and bridges require special tools. The regluing must be done right the first time or you can damage your tone.
There is probably nothing wrong with your top. I have found that people often notice the natural arch of their top when they are looking for the reason that their guitar doesn't play as comfortably as it once did. You may be due for an action set or even a neck reset. Strum the guitar and watch the excursion of the strings. Sight down the edge of your neck and see if the fingerboard "ski jumps" as it goes over the body. Look for fret wear and neck warpage. See if the guitar plays much easier with a capo. Actions deteriorate over a span of a few years. It may be time to visit your luthier.

Steve Mason