Someone brought up snow.. A few times In have had 8-10" of it on my roof when camping. Had to use a broom to brush it off to bring the slide in when it was time to leave. I think a topper would have been a pain to mess with then. I imagine that the snow load would've pushed the topper onto the roof. Melting snow from the heat inside would've likely made it wet between the topper and the roof and it may have frozen to the roof at night.