This birth answers a lot of questions. He's still alive in 1911/1921 but cannot find him from 1856 until 1911!!--that's 5 census
SS
Digressing a bit to Henry in the hope that earlier might find him with his mother? In 1921 and 1911 he is with his wife Jane.
!891 Census,
RG 12/4189/106/4
Chopwell
Henry Clemens, head, m, 36, coal miner, Quarrington* Co Durham
Jane do, wife, m, 36, new Seaham, do
Henry do, sons, 5, Wst Cornforth do
Jane do, daur, 2, do do
*(Quarrington not far from his actual birthplace of Trimdon)
Jane's birth: Jane Clemens, 3rd q 1888, Stockton 10a, 108, mother's maiden surname
Boyle.
Which leads to Henry in 1881, a boarder with the
Boyle family in Cornforth, plus their married daughter Jane Cuthbertson, RG 11/4902/26/46
Marriage Henry Clemens and Jane Cuthbertson, 4q 1886, Easington 10a, 505.
But can't yet find him earlier than 1881

He is very challenged re his birthplace - it's different on every census. In 1881 it's Ferryhill.