What does the engineered reinforcement sheet that comes with a Pima County pool permit actually require?
Verified against the primary source on .
The AMMTEC standard detail plan, approved by Pima County as master plan P18MP00069 D2 on 2018-11-28, sets minimum vertical reinforcement at #3 bar on 12 inch centers and standard horizontal reinforcement at #3 on 12 inch centers, with 3 inches of minimum cover. Several conditions on the sheet increase it, and the per-depth schedule has to be read off the sealed sheet in your own permit set.
Arizona codifies no minimum shell reinforcement for a residential pool, which leaves homeowners with nothing to compare a proposal against. There is a baseline, it is just not in the code: it is the engineered standard detail plan that comes attached to the permit. In Pima County that is usually the AMMTEC Consultants, PLLC Standard Gunite and Reinforcement Detail Plan, approved as master plan P18MP00069 D2, dated 2018-11-28.
WHAT THE SHEET SETS AS THE FLOOR.
Minimum vertical reinforcement is #3 bar at 12 inches on centre. Additional vertical bars, which the sheet calls alternate bars, are added per its schedule.
Standard horizontal reinforcement is #3 bar at 12 inches on centre.
Minimum cover is 3 inches, typical.
WHAT INCREASES IT, in the sheet’s own terms.
Highly expansive soils: the floor shall be reinforced with #3 at 6 inches on centre each way. That is double the density of the base figure, and it is the sheet itself calling for it, not a builder upselling.
Pools located within wash areas: floor reinforcement should be increased to #3 bars on 6 inch centres each way.
Wall thickness exceeding 10 inches: a second curtain of reinforcement is placed 3 inches from the waterside face of the gunite.
At a transition: extra transverse #3 reinforcement spaced on 12 inch centres between the main bars, centred on the transition. It may be eliminated where no transition exists.
WHAT THE SHEET SAYS ABOUT WHAT THE POOL SITS ON, which matters as much as the steel. All pool, spa and water features shall be built on firm undisturbed native soil, or on engineered fill compacted to a minimum of 95 percent maximum density as determined by ASTM D698. The shell shall bear on native soil or on fill compacted to that same minimum. That one note is the engineering reason behind the rule about not reusing untested excavated spoil as structural fill.
WHAT IS NOT IN THIS RECORD, AND WHY. The sheet carries a full schedule mapping soil category A, B or C and pool depth from 5 to 11 feet to gunite thickness and alternate bar counts at each elevation. Those figures are not reproduced here. Two reasons, and both are real. First, the sheet is copyright 2018 AMMTEC Consultants, PLLC; stating what it requires is fair, reproducing its schedule is not. Second, the machine reading of that dense grid is not reliable enough to publish: the columns interleave and a number cannot be assigned to a row with confidence. Publishing engineering figures that were guessed from a bad scan would be worse than publishing nothing. Read the schedule off the sealed sheet in your own permit set.
HOW A HOMEOWNER USES THIS. Your permit set contains this sheet or its equivalent. It is the engineered baseline your pool is measured against, and it is the document to compare a builder’s proposed schedule to. Ask which soil category the design assumes, ask what bar spacing and gunite thickness that category calls for at your depth, and ask whether either of the expansive-soil or wash-area triggers applies to your lot. Those three questions are answerable from the sheet you already have.
Correction. The claim that there is no baseline to compare a pool reinforcement proposal against. There is no CODE minimum, which is a different thing: the engineered standard detail plan attached to the permit is the baseline.
Important. The sheet is a third party’s copyrighted sealed engineering document. Its requirements are stated here and attributed; the sheet, its drawings and its tabulated schedule are not reproduced and must not be. The per-depth thickness and alternate bar schedule is deliberately omitted because the available scan cannot be read reliably enough to publish. Read it off the sealed sheet in the permit set.
Authority: AMMTEC Consultants, PLLC, Standard Gunite and Reinforcement Detail Plan, Pima County approved master plan P18MP00069 D2, 2018-11-28. Copyright 2018 AMMTEC Consultants, PLLC.. Verified 2026-09-13. Evidence grade: VERIFIED.
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