Shingles Specified on a 1-1/2:12 Roof and an Unbuildable Eave Detail

Two of the four issues are code violations and two are design carryover.

Code violations:

1. Shingles below the minimum slope. Asphalt shingles are limited to slopes of 2:12 or steeper (IRC R905.2.2). At 1-1/2:12 the shingles are not a permitted covering at all, and no manufacturer will warrant them there. The code path is R905.1.1 to a covering approved for the slope: modified bitumen, built-up, single-ply, or sprayed polyurethane, each installed at or above its listed minimum (commonly 1/4:12) with positive drainage to a drain or scupper.
2. Drip edge and underlayment sequence. The correct sequence is underlayment over the drip edge at the eave and drip edge over the underlayment at the rake (IRC R905.2.8.5). The detail reverses the eave, which routes water behind the edge metal and into the fascia - a slow, invisible rot rather than a drip.

Not violations, but traps:

1. The single layer of felt is correct at 5:12. Double underlayment is required only in the 2:12-to-under-4:12 band (R905.1.1). There is no area in that band here, so resist the urge to 'correct' it and generate a change order you cannot support.
2. Ice dam membrane is not a Louisiana requirement. It is a northern spec carried over. It is not a substitute for a proper low-slope membrane, and keeping it in the spec buys nothing.

The judgment point: an inspector will fail the low-slope area regardless of what has happened for 30 years, and 'it never leaked' is not a code defense.

Notice first, money second - reversing that order is how contractors eat the cost.

1. Issue a written RFI today, not a phone call. State the code basis for each conflict, ask for a supplemental detail for the low-slope area, and state the schedule impact.
2. Notify the owner in writing at the same time, referencing the RFI, so the owner knows the design is being changed before the price is discussed.
3. Do not install shingles over 1-1/2:12. Proceeding with a known violation weakens your position on both cost and liability.
4. Re-sequence, don't stop. Tear off and dry in the 5:12 area and keep crews productive while the RFI runs; a stoppage claim is harder to defend than a re-sequenced one.
5. Get written direction plus a change order for cost and time before any low-slope work begins; ask the AHJ for its read in parallel, since the permit will be inspected against the code, not the drawing.

Who pays: in design-bid-build, the owner holds the design risk, so a code-required change is an owner cost - but only if you gave prompt written notice and did not build the defect. Proceed silently and the cost shifts to you, along with rework, failed inspection, and licensing exposure. The architect's oral 'never leaked' comment is worth nothing; your RFI is worth everything.

Treat appearance and the ice dam note as two separate change-order items; bundling them is how credits get lost.

Appearance. You cannot make a membrane look like a shingle from the ridge, but you can usually make it look like the existing roof from the parking lot: a granulated modified-bitumen capsheet in a color matched to the field shingles, or a coated single-ply in a comparable tone. Propose one option, price it, and get the owner's written acceptance of the substitute appearance inside the change order. Never promise 'identical' - that sentence will be quoted back to you at final payment.

Ice dam note. Do not silently omit a specified product; silence becomes a credit dispute at closeout. Ask for a formal deletion and credit, or propose substituting a self-adhered secondary water barrier at the eaves and valleys, which has real value in a wind-driven-rain climate and is a defensible use of the money.

Internal note for the file: the north-facing low-slope area will pond if the existing framing has any deflection. Photograph the existing roof surface and note any standing water before tear-off. If the ponding later appears, you want it documented as pre-existing rather than as your new membrane's fault.