What should an apartment roofing bid include?

Two EPA roofing design figures

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What should multifamily roofing bids say about material and pitch?

For multifamily roofing material selection, EPA gives the pitch guidance with its metal-roof exception: “Select roofing material in accordance with the requirements of the Whole Building Design Guide for low-sloped and steep-sloped roofs. NOTE: Low-sloped roofs are defined as roofs with a slope less than or equal to 3:12 (25 percent). However, with the exception of metal roofs, most low-slope roofs must have a minimum slope of ¼:12 (2 percent). Steep-slope roofs are defined as roofs whose slope is greater than 25 percent. Some materials can be used on both low and steep slopes, while others are limited to either low or steep slopes.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Name the roofing materials and measured roof pitch in the requested scope so the proposed material can be compared with the surface it will cover. Keep the metal-roof exception beside EPA’s minimum for most low-slope roofs when discussing roof pitch; that recommendation is not a single slope requirement for every roof material. Ask the roofing materials schedule to identify the system proposed for each building rather than treating every apartment roof as the same surface.

For defining the roof assembly being priced, EPA explains the distinction between its layers: “In roof-and-ceiling assemblies, the rain water control portion of the roofing system may be separated from insulation and air barrier layers by a vented attic space. In this case, rainwater control continuity is traced through the roofing system, while air barrier and insulation continuity may be traced at ceiling level. In this section, the term roof assembly refers to the entire assembly that provides rain protection, thermal insulation, air barriers and condensation control.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Identify the rainwater control layer, insulation and air barrier in the existing roof assembly and the portion the proposal would address. A roof assembly with a vented attic can have rainwater control at the roofing and insulation and air barrier continuity at ceiling level. The roof assembly description gives the manager a way to distinguish surface work from work involving other layers before comparing the written scopes.

Describe the roofing material and pitch on InstaBids to request bids for that scope.

How should an apartment roofing scope address condensation?

For deciding between vented and non-vented roofing, EPA identifies the design considerations: “Step 1: Determine whether to use a vented or non- vented roofing system based on climatic and space- use considerations.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Ask the proposal to identify whether the existing assembly is vented or non-vented and how climate and space use inform the proposed assembly. A vented or non-vented description belongs beside the roof section drawing, with the relevant building use made explicit. Record the vented or non-vented arrangement separately for apartment buildings with different roof construction, rather than carrying one description across the entire property.

For one specific non-vented low-slope air-barrier option, EPA states: “y y Fully adhered roofing membranes can be used to make the air barrier in non-vented low-slope roof systems.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

If fully adhered roofing membranes are proposed as the air barrier, ask the scope to identify the non-vented low-slope system and the role that membrane would perform. Fully adhered roofing membranes in this guidance are an option for that particular assembly, not a statement that every roofing membrane acts as an air barrier. Name the fully adhered roofing membranes in the assembly schedule so the air-control role can be compared with the proposed water-control role.

Include the roof assembly and condensation-control details in the job you post on InstaBids.

What drainage details belong in an apartment roofing bid?

For positive roof drainage design, EPA lists the design inputs and drainage window together: “• Design site water collection and disposal systems to provide positive roof drainage where: y y All loading deflections of the roof deck are considered. y y Local rainfall rates are considered. y y The roofing manufacturer’s drain placement requirements are followed. y y Roof drainage within a maximum of 48 hours after precipitation is ensured.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Ask the positive roof drainage scope to identify roof-deck deflection, local rainfall information and the roofing manufacturer’s drain placement requirements. The 48 hours describes EPA’s roof drainage design guidance after precipitation; it is not a promised repair response time. Keep the drain placement assumptions visible alongside the building and roof areas covered by the proposal so the manager can see the basis for the drainage work.

For standing water and roof-surface damage, EPA explains the mechanism: “Standing water can damage the gravel and the granule or liquid coatings on roofs. Once these coatings are damaged, sunlight can degrade the roofing membrane.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Ask the standing water findings to locate the affected roof area and record the condition of its gravel, granule or liquid coatings. Where standing water is observed, request photographs and roof locations that connect the observation to the drainage work proposed. EPA’s roofing membrane explanation gives a reason to include coating condition in those findings, without assuming that a photograph alone establishes how much of a roof requires work.

Use InstaBids to share the proposed roofing drainage scope with bidders.

What should apartment roof flashing inspections cover?

For roof flashing inspection, EPA gives these details and the temporary-repair check: “• Inspect flashings at roof-wall intersections and at curbs. Look for loose flashing or missing fasteners, open ends or lap joints, unsealed corners and rusted or corroded metal. If caulk or roofing tar has been used as a temporary repair, inspect for cracks. Also inspect flashings around curbs, access hatches and rooftop equipment. Where deflection is required, make sure that roof panels and flashings move independently.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

List roof-wall intersections and curbs as inspection locations in the requested scope, then ask findings to identify loose flashing, missing fasteners, open ends, lap joints, unsealed corners and corrosion by location. A roof flashing report can distinguish the locations around access hatches and rooftop equipment from those at roof-wall intersections. Where caulk or roofing tar appears as a temporary repair, ask the findings to describe cracks at that temporary repair and the work proposed for that location.

Ask roof flashing proposals to connect each location in the findings with the corresponding line of proposed work. For roof-wall intersections where deflection is required, retain EPA’s guidance about independent movement of roof panels and flashings in the technical scope. A roof flashing allowance with named locations is easier to compare with the inspection findings than a single allowance covering unspecified flashing work throughout the property.

Put roof flashing inspection locations into the work you describe on InstaBids.

What roofing handover and shingle maintenance details should be written down?

For the roofing construction handover, EPA recommends documenting operation and maintenance responsibilities: “Guidance 1: Provide or direct contractors, subcontractors or manufacturers to provide operation and maintenance information required to maintain moisture control elements of the roof assemblies. The builder’s responsibilities should be spelled out in the contracts and may include: • Signs of roofing and roof penetration failure. • Frequency of inspection. • Method of repairing problems.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

Ask the operation and maintenance information to identify signs of roofing and roof penetration failure, inspection frequency and methods for repairing problems. Put the operation and maintenance information requested from the builder in the written contract scope so the handover has a defined set of documents. The frequency of inspection and method of repairing problems belong with the system information, giving the manager a record to use after the roofing work is complete.

For asphalt shingle maintenance, EPA gives the direction of cleaning as well as the area needing attention: “Pay particular attention to the tops of the vertical slots between tabs. This area is usually the last to dry. Moss and lichen growth on asphalt roofs keeps the roofing materials damp, so use a water hose and nozzle to remove moss and lichen. Spray from the roof facing down the slope to avoid spraying water up under the shingles.” (US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies); read 2026-11-06.

For asphalt shingle roofs, ask the maintenance scope to identify the vertical slots between tabs and any moss and lichen observed. If moss and lichen cleaning is proposed, retain EPA’s direction to spray from the roof facing down the slope and avoid spraying water up under the shingles. Keep moss and lichen cleaning distinct from a claim about the cause of every damp area, and ask the report to locate the particular asphalt shingle areas being addressed.

Add roofing handover and shingle care details to the job you post on InstaBids.

Roofing guidance to carry into the scope

Apartment roofing written-scope checklist

• Roofing materials and roof pitch: list the proposed system for each roof; retain the exception for metal roofs when referring to EPA’s minimum of ¼:12 (2 percent) for most low-slope roofs.
• Roof assembly: identify rainwater control, insulation and air barrier layers and which layers the proposed work addresses.
• Vented or non-vented roofing: record the existing arrangement and the climatic and space-use considerations for the proposal.
• Fully adhered roofing membranes: if proposed as the air barrier, identify the non-vented low-slope roof system and the membrane’s role.
• Positive roof drainage: identify deflections, local rainfall, roofing manufacturer drain placement and EPA’s maximum 48 hours after precipitation.
• Standing water: locate observed ponding and coating condition in roof photographs and written findings.
• Roof flashing: locate roof-wall intersections, curbs, hatches, equipment and temporary repairs; request findings linked to proposed work.
• Operation and maintenance information: specify signs of roofing failure, frequency of inspection and repair-method documents in the builder’s handover scope.
• Asphalt shingle maintenance: document moss and lichen, the vertical slots between tabs and any proposed cleaning down the slope.

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Compare the roofing layers and locations behind each bid

Compare roofing materials beside the measured roof pitch for each building. Compare positive roof drainage assumptions, including manufacturer drain placement, alongside the drainage work in each proposal.

Compare roof flashing findings at roof-wall intersections and curbs with the written repair locations. Compare the operation and maintenance information in the handover scope with the builder’s stated responsibilities.

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Sources

• US EPA — Moisture Control Guidance, Roof and Ceiling Assemblies, read 2026-11-06: www.epa.gov