In the pursuit of making more of my own gear, I want to make a TQ for two people to use in a roof tent. I need to join the material due to the width and I'm wondering what type of seam to use. A flat felled seam would be overkill I think - should I just join the two halves together with a running stitch then turn the other way round so the unfinished section is inside? I can't see any real pressure being exerted on that seam but I'd appreciate any advice from those more experienced than me.