  The SoLid detector was constructed during 2017 and started to take data in
December 2017. Commissioning a new detector implies defining and understanding
a whole set of new variables. On the one hand the environmental conditions are
followed, and on the other hand quantities related to the stability of the
detector are monitored. Cosmic muons are ideal for studying the stability of
SoLid, because of their abundance due to the small overburden. Muons can be
used to study the timing synchronisation and energy calibration of the detector
on a daily timescale. They can be used to monitor the detector stability and to
correlate it with the environmental conditions. Muons also create secondary
particles along their trajectory that can be detected and used for
commissioning. For instance, spallation neutrons that are thermalized and
captured in the detector can be used to verify the thermalisation properties of
the detector. Stopping muon decays allow for a check of the muon decay time.
