Most Indiana Limestone projects are awarded to a supplier or "fabricator" through a bid process. Prospective bidders are sometimes contacted by (typically) the mason or the general contractor and asked to provide a stone price for the project. In other cases the prospective bidder learns of the job through one of the plan services to which many companies subscribe. The explosive growth of the Internet has made it possible to access these services online, then do a search for projects that list limestone to determine if it's a project the company is interested in bidding. Some companies will also access projects that have specified other materials such as pre-cast concrete in an effort to provide a bid for a natural stone alternative. Once the company decides the project is of interest to them, they will order the plans with an eye toward bidding the project. From there, the following sequence of events typically occurs:
1. Once the plans are received by the fabricator, the estimating department will review the specifications and architectural drawings. They will then do a "take-off," where the quantities of stone are calculated and material, labor and freight costs are determined. From this information a detailed bid proposal will be prepared for the contractor/customer. Occasionally the contractor who is seeking the price will furnish the take-off.
2. Upon the awarding of the contract, the successful bidder will prepare shop drawings accurately detailing the fabricator's interpretation of the architect's design intent for the limestone/cut stone. The shop drawings are then submitted to the contractor/customer for their use in the approval process. Often, in this "fast-track" world, the most efficient process in terms of time is for the shop drawings to be submitted in phases as they're completed, then reviewed and returned in the same manner. The shop drawing approval is a very critical stage of the process, as these are typically reviewed and approved by the architect, general contractor and the mason contractor. The limestone fabricator/supplier will rely 100% on the information obtained from the field contractors and the architect in fabricating the stone. This reliance is necessary in large part because the limestone supplier is typically some distance away from the project and is not generally involved in establishing or verifying shop drawing dimensions. The engineering of the limestone connections, if required, is done during this phase of the project. Stone suppliers typically supply the stone with the required holes, slots chases and sinkages for the anchoring system, but seldom provide the anchors themselves. This responsibility typically falls on the mason or the erector, or may be assigned by the general contractor, though the stone fabricator may assist in recommending anchoring systems. It is standard practice for the architect to indicate, generally, the anchor system for each typical condition, including anchor type, size and location, and to judge or approve or change the extension of that system shown on shop drawings.
This is in line with standard practice and is not a result of applied engineering. The proper size and type of anchor depend upon design loads and specification requirements. Stone suppliers are generally not set up to do engineering. If engineering analysis is required of the supplier, this must be clearly and explicitly called out in the specifications so that the prospective bidder can address it during the bid process. Often this is done by securing a bid for this part of the project from an engineering firm not directly affiliated with the fabricator. In general, engineers prefer to work from shop drawings that have been reviewed and approved for jointing, as that reduces the chances of something changing and having to be re-engineered.
3. Upon receipt of the approved shop drawings, the fabricator begins to prepare shop tickets, patterns, programming and tooling. The raw material is selected and obtained from the quarry, and the production sequence and scheduling can now be effectively established. The stone will be fabricated per the approved shop drawings and packaged for shipment. Note that attempts to establish accurate delivery schedules prior to the receipt of the approved shop drawings can be detrimental to the project as they are difficult to determine. Timelines for the approval and engineering (if required) can vary immensely due to issues associated with field measurements and verifications, as well as the individual schedules of those involved in the review process. Reviewing, approving and returning the drawings to the fabricator in a timely manner will help move the project along to an on-time completion. Problems occasionally occur, particularly on large projects, when the customer changes the delivery sequence after the fabrication process has begun. Maintaining the predetermined sequence will help the job go smoother, as the fabrication and delivery can proceed in an orderly manner.
4. Setting drawings are created during the shop ticket preparation phase of the project. These drawings will identify each specific piece of stone, as well as its location and, if applicable, its required attachment.
5. While initial delivery will depend on the supplier's schedule and possibly other variables, 8 to 10 weeks from receipt of approved shop drawings is typical, as of this writing, for most projects. Deliveries will be accompanied by a packing list reflecting the quantity and piece marks included in each shipment. Each stone will be marked with its piece mark which will correspond with the setting drawings. Any stone damaged in transit should be noted on the packing list.
The above is meant as a general guide to the process involved in bidding, fabricating and shipping Indiana Limestone to a project and may or may not pertain to other materials. The timeline mentioned above can be affected by many variables. Interested parties are urged to contact ILI members or the Institute during the design phase of the project to get a more accurate and timely estimate..