Leaking roof or condensation?
Hello all, I am hoping someone can shed some light on a situation I am having. When converting our bus, we decided to seal up the roof vent at the front of the bus. We filled it with spray foam from the top and then sealed the hole with poly and tuck tape. Our finished roof is all cedar toung and groove. We are now starting to see drips of water come down at the front of our bus near the driver. Picture the area behind where the top marker lights are, the water is coming from that area, but is coming from higher than where the marker lights are so we know it its not leaking through the seal of the lights. The obvious source of the problem we assumed was that the air vent wasn't sealed up properly, but I have climbed up on the roof and double checked and resealed with silicone and I really don't think water is getting in there. My question is, do you know if enough condensation could be building up between the cedar and the metal roof to cause it to drip down? By the way, the main time we see the water dripping is when we are parked with the nose downhill or if the breaks get hit hard, allowing the water to move to the front.
Did we screw ourselves by sealing up the air vent? Is the purpose of the air vent to allow ventilation to prevent condensation build up? Or should I not be worried about condensation and be looking for other areas where water could be leaking in? I live in Calgary Canada so the weather temperature can change drasticaly from evenings to mornings possibly causing the condensation. Anyone with experience in this area of knowledge that could give me a little direction? The last thing we want is a bunch of water sitting above, ruining our beautiful cedar roof, and who knows what else!