Regarding SOLEXX'S panel joint mating. They provide a "H" panel that slides in-between the 4' panels. I have their Oasis, 8' X 12', live in the SW corner of Brookings, OR. In the spring weather, cool, sunny, had temperatures in the high 90 inside. I have the temperature controlled exhaust fan with the vent louvers tied together electrically. Ended up, ordering another door frame and had that screened. It helps keep the temp lower. Key word there is LOWER. Come the cooler months, I will replace the poly-siding door back on. As we all know, SOLEXX is a white-ish material. With that in mind, you will understand why there is a decal just to the right of the door frame, "SLOEXX GROWING ROOM, 11th COMMANDMENT; Thou shalt not call me GREENHOUSE." Mine has only been up since April, no leaks. Am growing green beans, snow peas, tomatoes, cucumbers, yellow squash, zucchini and bell peppers. Already harvesting snow peas, green beans, cucumbers, yellow squash, and zucchini. Needless to say, I've got lots of trellising up.