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High
Density Shelving Systems require a floor loading
analysis in storied facilities to ensure the floor
can hold the weight of the system. Below is a
description of floor loading and why this review
is necessary.
Floor
Loading Considerations
There
are two types of loads in high density shelving
systems, live and dead. Live loads deals with
the moving loads the footprint of the high density
shelving system. Dead loads deals with the fixed
weight of the high density shelving system footprint.
Most buildings have
a minimum floor loading rating of 50 lbs per square
foot. Floors designed for library system require
a minimum of 100 lbs per square foot.
Most floors are
not designed with high density shelving systems
in mind and are usually not built to meet the
loads required for a high density system. Because
of this, floors require a floor loading review
of the high density shelving system footprint
before a system can be installed.
Floor loading is
very commonly mistaken by dividing the square
footage of the high density shelving system into
the total weight of the system. Floor loading
is much more complex and requires a certified
structural engineer to provide a review of the
floor and high density system for installation.
Loads on high density
shelving systems are defined as point loads on
the rails as the weight from the shelving, media
and carriages is transferred to the wheels and
from there to the slab and then the structure.
This analysis shows that dividing the square footage
into the system weight will not be sufficient
as these systems have point load distribution
and are not distributed throughout.
A high density shelving
system layout with rail placement showing the
center to center measurements is required for
a structural analysis. The weight transfer between
rail centers will vary per system.
Our local ASA members
are experts in the design and implementation of
high density shelving systems and will provide
details with CAD Drawings, number of carriages
and their dimensions, shelving dimensions and
most importantly the amount of usable filing inches
in the high density system. Media weight makes
up the majority of the system and is crucial when
calculating floor loading.
Working with ASA
members, you will receive a formula showing the
high density shelving system components and media
weights separately. This formula will show how
the media weights were calculated and the system
weights.
In some cases the
structural review of a high density shelving system
allows for a complete installation with no modification
to the floor. When the high density shelving system
load exceeds that of the floor, there are options
available to modify the floor for a high density
shelving system installation. Increasing the amount
of rails in a high density system adds another
point load in the system lowering the point loads
on all rails. Decreasing the height of the shelving
is another option available to customers. This
option will reduce the media weight across the
system and may allow for an install without reinforcing
the floor. Other solutions include changing the
direction of the rails, using structural tubing,
changing the configuration of the system or the
last case scenario, floor reinforcement.
Floor reinforcement
is common in high rise facilities where tenants
reinforce the floor with steel plates or beams.
Certified structural engineers will provide detailed
information on how floors will need reinforced
for customers to make a final decision on how
to install a high density shelving system in their
facility.
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