Illinois Commercial and Industrial Roofing Contractor

Arbitration uses a third-party arbitrator acting as a judge whose arbitral award is legally binding on all parties, while in mediation the mediator only facilitates discussion and the parties set the terms.

Collaborative law has no neutral mediator or arbitrator—the parties negotiate through their own advocates (usually lawyers) and are expected to settle without further ADR or litigation.

The positive method divides an irregular roof into rectangles and adds their areas; the negative method extends roof lines into one large rectangle and subtracts the non-roof areas—both give identical results.

A nonnailable deck (example: structural concrete) is one where mechanical fasteners are not used to attach roof system components—so a four-ply cold-applied BUR on it requires primer, ply sheet and adhesive—while nailable decks (wood panels, wood planks, cementitious wood fiber panels, lightweight insulating concrete) use mechanical attachment; steel deck is a separate category used only for temporary roof configurations.

Channel (pan) flashing, used with S-tile, pan-and-cover and most interlocking tile, extends under the roof covering along the length of the wall, while step flashing is used with plain (flat) tile and is interwoven between each course.

Fiberglass shingles have a fiberglass base mat saturated and covered with flexible asphalt and surfaced with mineral granules; organic shingles use a cellulose-fiber base mat.

CPM graphically shows the interdependent relationships of tasks; calendar and bar chart methods do not show interdependencies (their shared weakness), though calendar scheduling's advantage is linking tasks to specific dates such as deliveries, payment schedules and vacations.

Free float is the time an activity can be delayed without impacting the early start of the next activity; total float is leeway without delaying the overall project completion date (contingency time is a separate buffer between tasks for unforeseen delays).

In a lump-sum contract the contractor takes essentially all the risk for a predetermined price (bearing unforeseen costs but keeping savings); in cost-plus the contractor is reimbursed actual labor and material costs plus a percentage or fixed-fee markup, with payments based on actual costs and reconciliation once actual costs are known.

Addenda are changes to contract documents made before the contract is awarded; modifications are changes after the contract is signed and executed, and change orders are written owner-contractor agreements changing an executed contract.

In design/build the owner contracts with one company that assembles the design and construction team to take the project from design through completed construction; turnkey adds expanded responsibilities—the contractor also obtains financing and land.

The construction standard sets a permissible exposure of 90 dBA as an eight-hour TWA; above it, feasible engineering or administrative controls must be used, with hearing protection where controls do not reduce exposure enough. 85 dBA is the hearing conservation action level under the general industry standard, not the construction action level.

The action level is 30 micrograms per cubic meter of air as an eight-hour TWA (triggering obligations such as biological monitoring/blood sampling); the PEL is a separate, higher threshold of 50 µg/m³.

A repair involves removal or disturbance of in-place ACRM no greater than can be contained in one standard-sized (60- by 60-inch) waste bag; larger amounts are classified as removals, triggering additional regulatory requirements.

Chemical grout crack injection seals cracks and voids within the concrete, while acrylamide gel injection creates a dense, water-impermeable mass in the earth opposite the leaking crack (best against earth; not satisfactory on plaza decks where the gel can dry and shrink).