There have been four helical manufactures to receive ESR’s
for their products. No ESR’s have been issued in the last several years. Is it
possible that the remaining manufacturers have realized that the current rules
do more to hinder jurisdictional approvals than help?
On Commercial projects there are usually design submittal
requirements that require a licensed engineering stamp to be included and there
are almost universally soil borings to provide needed data for design. As such the
ICC ESR does not provide significant tangible additional benefits as the local
jurisdictions rely on the stamp of the local engineer, who almost always insist
on boring data as a matter of practice regardless of ICC requirements.
On residential projects, the ICC requirement provides a
distinct disadvantage. One of the requirements of all ESR issued products is a
soil report with borings on every project. If the Regulating officials read and
enforce that requirement in the ESR, then a full geo report is required with
borings. On residential projects, this provides little benefit at cost of
$3000-$5000 or more. This is required on even the smallest project of a few
thousand dollars, providing a disincentive to pull permits or seek
jurisdictional approval because of its imbalance in costs and benefits for the
homeowner.
On residential projects the governing factor is almost
always the span of the footings between the piles as opposed to the weight of
the structure. What this means is the factor of safety is usually many times
more than the required factor of 2. Even if the piles lock up on a hard lens
with soft soil underneath, there is little likelihood of failure because of the
large safety factors and lighter loads.
The reality is that although the requirement is that the ICC
requires soil borings in all residential applications, it is almost universally
ignored, signaling an almost unanimous rejection of it in practice and setting
up a de facto alternative. This is a dangerous precedent with unpredictable
outcomes and inconsistent enforcement. The opposite of what ICC intended.
There is a possible alternative. The IRC is intended to
provide prescriptive measures in residential applications with a larger FOS to
compensate. I think this qualifies.
Rather than requiring soil reports with borings, a standardized prescriptive
measure could be prescribed with larger FOS than non-prescriptive applications
that could eliminate the need for borings. On new residential construction the
same sort of logic is used with a minimum soil bearing capacity without
borings.
As in other IRC applications permits and pre-engineered ICC
approved products could be required, thus preserving the quality of the
products and proper application and installation. Code officials could have a
standard that could be uniformly enforced and the industry would more uniformly
regulated, providing motivation for the remaining manufacturers to apply for and
finish becoming ICC approved, making the foundation repair industry safer and
more reliable, utilizing a standard that the industry is more likely to adopt
in practice.
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