I did learn the new extreme for my solar hot water thermosyphon manifold today. I filled the system back up yesterday thinking it would survive the overnight low. It has made it to 18 degrees several times but apparently 13 is a bit beyond tolerance levels. After the sun was up for about and hour, I heard water running. The big freeze popped the top right elbow on the rig. Caught it in plenty of time to shut off the hoses and only lost about a gallon of water. Pretty sure I have the parts to repair and get it back in service tomorrow morning in time for a warm shower by the end of the day.
Cut and welded together some flanges to add up top - giving a little more meat for the purlin attachments to the trusses. Seems like a good idea and it just felt like the right thing to do....that coming from someone who has no engineering training but plenty of practical building experience. I'll keep adding steel till I'm certain the roof won't blow away. 39,65,13,0