WTC1, WTC2, have apparently received an upgrade of fireproofing on all the floor joists between 1999-2001.
How is this even possible to get at and upgrade? Hmmmm...would like to hear rational intput.
It is VERY possible.
Areas that receive fireproofing :
- Celeing and floor connecttions between the concrete and window walls
- Top and bottom of fire-escape hallways
- ductwork gets 'insulation' fire protection
- electrical channel passing between floors are sealed with fire-caulking
- All 'fire-stop' walls are sealed with combination plaster/ fire-caulking
Beyond that, in some types of buildings there is a spray-on insulation made from glue and paper to the same effect of asbestos... when used covers ALL ceiling metal in required areas.
The process would roughly be :
- Open affected areas (demolition) (1-5 days per floor depending on how much gets torn off)
- apply fire-protection (1-2 days)
- drywall (1-2 days)
- electrical (if any changes ... 1-7 days)
- Plumbing (if any changes)
- Taping (4-6 days)
- Pain (1-2 days)
So really... even as a lowballed estimate, this type of change-over could take in the area of up to a month or so per floor... depending on the specific circumstances.
What might be the 'flick of a pen' for an architect could reflect 2-3 weeks worth of work once all the trades have gone through. BUT : being an office building much of the higher work could be accomplished simply by moving the ceiling tiles over... so that could also reduce my simplified estimates.
Could have had access to all floors by allegedly inspecting the fireproofing?
An inspector COULD go through all the floors to inspect the fireproofing... but, since the building itself had passed previous inspections, an inspector would only HAVE to go to the floors in which work was done that required inspection (electrical, plumbing, fire-proofing, garbage shafts, sprinklers, brickwork, etc)
Why an equal 30 floors in each tower and not all?
Also a few issues could come into play... perhaps only 30 floors had swapped over from asbestos... which requires specialized removal... perhaps 30 floors were seen as adequate access to plant explosives to make things look like a genuine collapse from fire... or about 50 other legitimate resons.
This is mostly from professional opinion...
