Got a wierd one here, when we have the furnace on and the camper starts heating up, the roof will make a loud snap noise, does it a couple times during the time the furnace is on. any suggestions? BTW its a 2000 coleman utah
It is most likely from heat expansion of the different pieces that make up the roof.
Different materials expand at different rates.You can try to locate the noise and maybe glue or anchor the offending part(s).