NM GS-21 Roofing Contractor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Roof slope ratio

Slope is rise over run, expressed as inches of vertical rise per 12 inches of horizontal run. A 4:12 roof rises 4 inches for every 12 inches of horizontal travel.

Low-slope threshold

Roofs below 2:12 are treated as low-slope and require membrane systems. Shingle and other steep-slope products are generally limited to 2:12 and above.

Double underlayment zone

Between 2:12 and 4:12, asphalt shingles typically require a double layer of underlayment. Above 4:12, a single layer is generally acceptable.

Ice dam membrane extent

Ice dam protection membrane runs along the eave and must extend from the eave edge to at least 24 inches inside the interior wall line of the heated space.

Ventilation ratio rule

Net free vent area is typically 1/150 of the vented ceiling area, reduced to 1/300 where a vapor retarder is installed or intake and exhaust vents are balanced.

Step flashing purpose

Step flashing is installed at sidewall-to-roof intersections in individual overlapping pieces woven with each shingle course to shed water away from the wall.

Valley flashing types

Open valleys expose metal flashing between roof planes; closed valleys cover the flashing with roofing material. Both direct water down the valley centerline.

Built-up roofing minimum slope

Built-up roofing requires a minimum slope of 1/4:12. Modified bitumen and single-ply membranes are also commonly specified at that same minimum.

Metal panel slope limits

Mechanically seamed metal panels can be installed as low as 1/4:12. Lapped, through-fastened metal panels typically require at least 3:12.

NM licensing authority

New Mexico construction contractors are licensed by the Construction Industries Division of the Regulation and Licensing Department, which administers trade and business examinations.

Specialty contractor limitation

A specialty contractor license limits work to the specific trade classification. A roofing licensee may not bid or perform work outside that licensed scope.

Qualifying party

A license is tied to a named qualifying party who meets experience requirements. If that person leaves, the contractor must notify the division and replace them.

License number disclosure

New Mexico licensed contractors must display the license number on contracts, bids, and advertising so the public can verify the license status.

Unlicensed contracting effect

Contracting without a required license is a violation subject to administrative penalties and can bar the contractor from recovering payment for the work performed.

Local code adoption

The Construction Industries Division adopts building codes by rule, including New Mexico amendments. Local jurisdictions may adopt and enforce their own codes within their boundaries.

License classification basis

License classifications are set by work type and dollar threshold. General contractors may perform all phases; specialty contractors are limited to their trade scope.

NM gross receipts tax

Gross receipts tax is imposed on the seller for doing business in New Mexico. Local option and municipal taxes are added, so the rate varies by location.

Construction services deduction

A contractor may deduct receipts from construction services on real property when gross receipts tax was paid on the materials, or may instead pay tax on materials and deduct the service.

Change order requirements

A change order must be written, signed by the owner, and state the revised scope, price, and time impact before the changed work begins.

Retainage practice

Retainage withholds a percentage of each progress payment, commonly 5 to 10 percent. The contract should state the percentage and the release conditions.

Lien recording deadline

A New Mexico mechanic's lien claimant must generally record the claim of lien within 120 days after last furnishing labor or materials, then enforce it by suit.

Markup versus margin

Markup is profit divided by cost. Margin is profit divided by price. A 25 percent markup yields only a 20 percent gross margin.

Worker misclassification risk

Treating employees as independent contractors creates liability for unpaid payroll taxes, workers' compensation premiums, and penalties. Control and direction tests govern classification.

Contract essential terms

A roofing contract should identify the parties, scope, price and payment schedule, dates, change-order procedure, warranty, lien rights, and dispute resolution.

Fall protection trigger

Under OSHA residential roofing rules, workers on roofs with slopes greater than 4:12 must use guardrails, safety nets, or personal fall arrest systems.

Fall arrest force limit

Personal fall arrest must limit maximum arresting force to 1,800 pounds and prevent free fall exceeding 6 feet, with anchorages rated at least 5,000 pounds per worker.

Ladder 4:1 rule

For every 4 feet of working ladder height, the base sits 1 foot from the wall. Extension ladders must extend 3 feet above the landing.

Ladder duty rating

A ladder's duty rating must equal or exceed the combined weight of the worker plus tools and materials carried. Never exceed the rated capacity.

Torch-applied fire watch

Hot work such as torch-applied modified bitumen requires a fire watch, removal of combustibles, and monitoring of concealed spaces after work ends.

IRC versus IBC

The IRC governs one- and two-family dwellings and townhouses. The IBC governs commercial and multifamily buildings, including required roof fire classifications.

Overhead line clearance

Maintain at least 10 feet of clearance from energized overhead lines up to 50 kV. Greater voltage requires increased clearance per the applicable table.

Sheathing fastener requirement

Roof sheathing thickness and fastener spacing are set by code and manufacturer instructions. Fasteners must penetrate framing to the specified depth to resist uplift.