Hot melt glue melts in the sun...or at least softens.  I once built a geodesic dome in the basement in late fall, each section made with hot melt and staples.
On a cloudy saturday morning  I began assembly, went flawlessly, last 2 rows....the SUN comes out, and dome sag set in.
Lesson learned, don't use hot melt glue where it's likely to get warm. lot of wasted matrials, time , and effort.
Harold, RV9A slooowlly being built