Rugs, Carpets and Carpeting - cement board seams showing through

My husband screwed the cement board down over a wooden floor and left the recommended spacing (1/8"?) between the boards. Then he filled the spaces with mortar and tape the way it was also recommended. Although he tried to make the seam area as level to the cement board as possible, there was still a hump along each seam that now shows through the carpet. We put down a commercial grade 100% olefin carpet with no padding because the porch could possibly get slightly damp at times. Should the seams have been sanded, which we didn't do? My husband said that would have torn up the taping that he had to put on each seam. Are we going to just have to live with all the taped seams (humps) showing through the carpet? If we DID rip up everything, I suppose the carpet wouldn't come up in one piece because of the adhesive. Any thoughts, please?!

Sorry to say, but you used the wrong underlayment and the wrong carpet for this application. Outdoor rated plywood and outdoor rated carpet & adhesive would have been the correct way to go. Unfortunately you will have to live with the underlayment seams showing for the life of this installation (which won't be long)