<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Datacenter owner/operator and retired engineering contractor here. <div><br></div><div>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. </div><div><br></div><div>See: <a href="https://msrs.com/new-construction/fully-adhered-vs-mechanically-attached/">https://msrs.com/new-construction/fully-adhered-vs-mechanically-attached/</a></div><div><br></div><div>Concrete is a superior substitute. Concrete deck your datacenter and you’re done. It’s considered pretty bulletproof. Figuratively and literally.</div><div><br></div><div>Our DCs have concrete floors walls and ceilings. </div><div><br></div><div><br><br><div id="AppleMailSignature">-Ben</div><div><br>On Sep 14, 2018, at 8:34 AM, Andrew Latham <<a href="mailto:lathama@gmail.com">lathama@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr">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.</div><br><div class="gmail_quote"><div dir="ltr">On Fri, Sep 14, 2018 at 10:03 AM Valeriu Vraciu <<a href="mailto:valeriu@roedu.net">valeriu@roedu.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br>
<br>
<br>
It may be somehow offtopic, but maybe someone can help understand the<br>
meaning of a requirement for Tier 4 DC.<br>
<br>
We have a project to build a Tier 4 datacenter. One of the requirements<br>
specified in TIA942 and related to roof of the building sounds like this:<br>
<br>
"double redundant with concrete deck (no mechanically attached systems)"<br>
<br>
For my understanding (being not a native English speaker) what exactly<br>
does this mean ?<br>
1. no mechanically attached to the roof systems (gear, equipment) like<br>
air-conditioning, generators etc.<br>
<br>
or<br>
<br>
2. the roof (double) is made from components that are not mechanically<br>
attached with bolts and such.<br>
<br>
<br>
Thanks in advance.<br>
<br>
<br>
-- <br>
Valeriu Vraciu<br>
RoEduNet<br>
<br>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">- Andrew "lathama" Latham -</div></div>
</div></blockquote></div></body></html>