  The effect of Anderson diagonal disorder on the topological surface
(``drumhead'') states of a Weyl nodal loop semimetal is addressed. Since
diagonal disorder breaks chiral symmetry, a winding number cannot be defined.
Seen as a perturbation, the weak random potential mixes the clean exponentially
localized drumhead states of the semimetal, thereby producing two effects: (i)
the algebraic decay of the surface states into the bulk; (ii) a broadening of
the low energy density of surface states of the open system due to degeneracy
lifting. This behavior persists with increasing disorder, up to the bulk
semimetal-to-metal transition at the critical disorder $W_{c}$. Above $W_{c}$,
the surface states hybridize with bulk states and become extended into the
bulk.
