Matls IM 449.05, revised 4/21/20

This memorandum covers Manhole Adjustment Extension Rings and Castings for use on all projects. The adjustment or extension ring for the manhole may be furnished either as a segmented ring or as a one-unit ring. When it is used, it will effectively raise the height of the manhole to accommodate the final overlay thickness without a need to raise the entire frame from its original foundation. Adjustment and extension rings shall comply to specification 4149.04 H. Castings Shall comply to specification 4149.04 I.

Approved sources are listed in the Materials Approved Products Listing Enterprise (MAPLE).

FABRICATOR APPROVAL

Requests for source approval shall be made to the Construction and Materials Bureau. Approval will be based on evaluation of the product information provided by the Fabricator or manufacturer.

CERTIFICATION STATEMENT:

Shipments to projects shall be accompanied by bill of lading and certificate of compliance with the following information:

1. Fabricator or Manufacturer Name

2. Certification Statement

2. Signature of Authorized Person

3. County, Project Number and Contract Number

4. Castings shall conform to the shape, weight, and dimensions of the fabricator approved shop drawings. Castings or Concrete adjustment rings Shall conform to the following:

“It is hereby certified that the Casting or concrete adjustment ring listed was manufactured to meet the applicable requirements of the Iowa Department of Transportation and the requirements of the applicable ASTM. We also certify that any steel or iron used to fabricate this material meets the requirement of IM 107 Group 2, Buy America. “

5. Polyethylene or Polypropylene adjustment or extension rings shall be certified to the applicable ASTM.

ACCEPTANCE

Acceptance is based on Approved Sources listed in Appendix A of this IM and a certification statement. Concrete adjustment rings may also be accepted from sources in IM 445.01 Appendix B and a certification statement.