This style camper hatch may put you in trouble for rot:

Hi PJay 9:

I've had a custom cut clear 8mil thick plastic tarp over the hatch since before this incessant rain has been falling. The plastic sheet is well taped on via house wrap tape (red). I just checked the hatch minutes ago: completely dry.

Thanks for the hatch links! Excellent assortment. My hatch size (propane) is: Door 13.5 x 13.5 inches; outside frame dimensions: 15.5 x 15.5 inches. It is raining too hard at the moment to measure the inside frame dimensions.