Here's what Keystone has published in the FAQ section of their website regarding walking on Keystone RV roofs:
"If your unit does not have a ladder please do not walk on roof. In a case where your unit has a ladder, please pay attention to weight restrictions on the ladder equipped on RV. Please take ordinary safety precautions and do not take unnecessary risk. Do not allow children to climb ladders or be on roof. Please contact your dealership if you have more questions regarding roof structure, maintenance, service, and warranty items. You may also contact Keystone at
[email protected] or by phone at 1-866-425-4369."
I won't interpret their intended message, but will just identify these two "points to consider".
1. Does Keystone "infer" that the weight limit for the roof is "regulated" by the weight limit for the ladder? If so, most ladders have a 200-250 pound maximum allowed weight.... So, if you can't use the ladder to climb onto the roof, will it support more than the ladder ????
2. If you "weigh more than the average RV owner" (more than about 210-220 pounds) it might be a consideration to contact Keystone at the number in their FAQ (posted about 10 lines up) and simply ask them, "I weigh 320 pounds. Can I use the ladder to climb on my roof? If not, will the roof structure safely support my weight without damage if I use a different ladder to climb on the roof?" With those two answers, maybe you can make an "educated decision" about walking on your roof.
FWIW: Most RV roof rafter systems are either stamped 18 ga steel or "glued/stapled whitewood 1x1" construction. Crushing or bending either type rafter will be a significant cost to repair. 300+ pounds is "a considerable load" to put on an "ultra-light" or "X-Lite" construction system. YMMV.....