How do you join two rolls on the long edges, so you don't get 'gaposis' along the seam?

So our 8mm Strong Rubber Rolls and all of our rolled rubber flooring is approximately 4' wide, but are not exactly that. So to create a seam that won't have gaps here and there what we recommend is to place one roll on top of the other to get the seam as straight as possible. The overlap on this doesn't have to be very large, a few inches at best. Once the seam is straight, you can use some double-sided tape under the rolls or place some seam sealer glue between the seam. Both methods will ensure that the rolls will not gap. You can also just use our seam sealer in conjunction with the double-sided tape without cutting the seams straight to keep them from gapping. The tape will keep the rolls in place and the seam sealer glue will lock and fill in the flooring.