  SNOLAB is one of the deepest underground laboratories in the world with an
overburden of 2092 m. The SNO+ detector is designed to achieve several
fundamental physics goals as a low-background experiment, particularly
measuring the Earth's geoneutrino flux. Here we evaluate the effect of the 2 km
overburden on the predicted crustal geoneutrino signal at SNO+. A refined 3D
model of the 50 x 50 km upper crust surrounding the detector and a full
calculation of survival probability are used to model the U and Th geoneutrino
signal. Comparing this signal with that obtained by placing SNO+ at sea level,
we highlight a $1.4^{+1.8}_{-0.9}$ TNU signal difference, corresponding to the
~5% of the total crustal contribution. Finally, the impact of the additional
crust extending from sea level up to ~300 m was estimated.
