What does the expression 'mount the scaffold' mean?
to climb/ascend a scaffold
Yes, 'mount the scaffold' is a metaphoric idiom - referring to the scaffold used for executions. It means someone is in big trouble!

I can't imagine anyone saying they 'mount' a literal real-life scaffold.
Students: We have free audio pronunciation exercises.
In addition to what Marius said:

Depending on context, mount the scaffold can have different meanings. For instance, if someone is in trouble at work and needs to meet with an angry boss, a co-worker might say something like Prepare to mount the scaffold. In this context the speaker probably is thinking of the second definition, though the person is not being literal. (He/she is exaggerating for effect).

That said, the other uses probably are more common these days. Emotion: smile

from www.dictionary.com

scaf‧fold –noun
1.a temporary structure for holding workers and materials during the erection, repair, or decoration of a building.

2.an elevated platform on which a criminal is executed, usually by hanging.

3.a raised platform or stage for exhibiting spectacles, seating spectators, etc.

4.any raised framework.


a suspended platform that is used by painters, window washers, and others for working on a tall structure, as a skyscraper.

(other definitions)
 nona the brit's reply was promoted to an answer.
Students: Are you brave enough to let our tutors analyse your pronunciation?
I guess it means to go and speak what you want to say

No. It means basically 'go to face big trouble or danger'.