Mr Simmonds said the shutter would remain closed today and two others used instead, so that visitors could look at the work.
“It’s really important we share this with everybody.”
He added he was expecting extra people to visit on Tuesday in addition to the thousands who had already booked.
“It’s going to be a busy day.”
Mr Simmons later confirmed that the artwork would be protected.
“We’ll definitely preserve it. We might even look at putting some perspex around it.
“The last thing we want with typical London weather, having just come through one of the worst winters ever, is to see this damaged by the weather.”
He added it was likely to remain in the same location for the immediate future but might then be relocated to elsewhere on the site.