This Instructional Memorandum addresses the fabrication requirements for Type A and Type B signs to be used on highway construction projects. All materials incorporated into the fabricated signs shall conform to the Standard Specifications, plans and the applicable Materials Instructional Memorandums.



A sign fabricator must be on the Approved Fabricator List to furnish Type A or Type B signs. To become approved, the fabricator shall submit a written Quality Control Plan to the Construction and Materials Bureau for review. Upon approval of the Quality Control Plan the fabricator will be placed on the Approved Fabricator List within the Materials Approved Products Listing Enterprise (MAPLE), (Appendix A). Failure to comply with the following requirements shall be considered sufficient cause for suspension or termination of fabrication approval:


The written Quality Control Plan shall address, as a minimum, the following elements to ensure that the requirements of the contract documents will be met during the fabrication process:


1.   Notification of shop drawing submittal

2.   Notification of material availability for sampling and testing

3.   Process used to maintain tested material identity (tags or markings, lot identification, isolated warehouse storage)

4.   Notification of fabrication schedule

5.   Identification of personnel responsible for quality control

6.   Sign Fabrication quality control process and documentation records. As a minimum, the following quality control items shall be verified and documented:


A.   Sign blank preparation.

B.   Sheeting application inspection (color uniformity, application quality)

C.  Letter style and size

D.  Letter message spacing

E.   Final message content

F.   Overall conformance to the approved shop drawing


The designated quality control person or persons shall perform documentation of quality checks at the time of fabrication.



The DME Office may sample materials for use on Iowa projects. Out-of-state fabricators may be requested to submit samples of their materials. These samples shall be delivered to the Iowa DOT Materials Laboratory in Ames, Iowa.


Sign sheeting and sign panels may be sampled for every lot of signs fabricated. A lot is defined as   10,000 sq. ft. of signs fabricated for Iowa DOT projects.


Reflective sheeting shall meet the requirements of ASTM D 4956 and may be sampled at a rate of one sample one square foot per lot. Samples shall have a minimum width of 4 in. A sample of each color and each type of reflective sheeting used in a lot may be obtained. Normally, samples will not be needed if less than 100 sq. ft. of a specific color or type of sheeting is used in a lot.


Aluminum sign blanks for type A signs and other aluminum sheeting used for signs shall meet the requirements of ASTM B-209, Alloy 5052-H38 or Alloy 6061-T6. Aluminum for signing projects may be sampled at the same frequency as reflective sheeting. A sample may be taken of each thickness and type of aluminum intended for use in a lot of fabricated signs. Samples shall be a minimum of 1 sq. ft. in surface area for sheet aluminum for Type A signs. For structural panels used in Type B signs, a 1 ft. length of panel may be required to be furnished.  Structural panels and other extrusions shall meet requirements of ASTM B 221 Alloy 6063-T6.


The fabricator shall furnish a copy of the aluminum producer Type B certification of compliance showing chemical and physical test results conforming to ASTM B-209 for materials used on Iowa Department of Transportation projects.


All fastening accessories may be sampled in accordance with the following schedule for each purchase order lot or shipment to the fabricator:


One          (1)         Sample per 800 pieces

Two          (2)         Samples per 801-8000 pieces

Three       (3)         Samples per 8001-22000 pieces

Five          (5)         Samples per 22000 and over.


NOTE: If a fabricator produces more than 40,000 sq. ft. of signs per year for Iowa DOT projects, then reflective sheeting and sign panels may be sampled quarterly. All colors and types of sheeting anticipated for use may be sampled. Each thickness and type of sign panel may be sampled. The small quantity exception of 100 sq. ft. of a specific color or type of reflective sheeting shall apply as described above.




The fabricator shall issue a shipping report / certification letter to the project engineer and DME of the District in which the project is located, or as directed, for each shipment of signs sent to Iowa projects. The report shall contain, as a minimum, the following information:


1.   Project Number, Contractor, and County.

2.   A listing of signs shipped, showing the sign message and identification number

3.   The area (square feet or square meter) of each sign being shipped

4.   Tabulation of materials used in the sign fabrication and copies of applicable material certifications

5.   A certification statement shall be on each shipping report / certification letter.  It shall be signed by a responsible company representative and is required to certify the signs were fabricated according to the plans / specifications, and materials for the signs meet the requirements of the specifications, including buy American requirements.



The fabricator shall keep all material approvals, certifications, shop drawings, and quality control documentation on file for a period of five years after shipment.



Signs will be accepted based on a shipping report / certification letter from an approved sign fabricator listed in Appendix A of MAPLE.


Damaged signs delivered to the project may be rejected.  Replacement of damaged or defective signs shall be furnished at the contractor’s expense.