tier 4 datacenter requirement "translation"


It may be somehow offtopic, but maybe someone can help understand the
meaning of a requirement for Tier 4 DC.

We have a project to build a Tier 4 datacenter. One of the requirements
specified in TIA942 and related to roof of the building sounds like this:

"double redundant with concrete deck (no mechanically attached systems)"

For my understanding (being not a native English speaker) what exactly
does this mean ?
1. no mechanically attached to the roof systems (gear, equipment) like
air-conditioning, generators etc.


2. the roof (double) is made from components that are not mechanically
attached with bolts and such.

Thanks in advance.

I would have to go check for sure but I believe it applies to screws or bolts that could pierce the membrane. A well sealed roof is all they are looking for.

Datacenter owner/operator and retired engineering contractor here.

They are not talking about “mechanical” systems such as HVAC, they are instead describing a “Mechanically attached roofing system”. That’s a specific term, and covers metal roofs of a specific type and construction.

See: https://msrs.com/new-construction/fully-adhered-vs-mechanically-attached/

Concrete is a superior substitute. Concrete deck your datacenter and you’re done. It’s considered pretty bulletproof. Figuratively and literally.

Our DCs have concrete floors walls and ceilings.