Didn't really think about weight. I did use 4 boxes of the Allure, 24 sq ft per box. I weighed a full box that I have left, and it comes in at 35 lbs., maybe about 1 1/2 lbs per sq. ft. So, I added 140 lbs to the rig, less 50 lbs or so for the old carpet and laminate that I removed. Figure I added 90-100 lbs or so.
I still have the carpeted area under the dianette and some carpet at the very rear of the bedroom to finish, hence my keeping the extra box I bought.