In the roofing industry, proficiency in reading blueprints is paramount, for estimating and for installation. However, a comprehensive understanding extends beyond the roof plan. It encompasses deciphering various components of blueprints like sections, elevations, schedules, architectural, structural, plumbing, HVAC, mechanical and electrical plans. Why is this expansive knowledge necessary? Because these documents often hold critical, sometimes overlooked, information. Take site plans for instance: while many might question their relevance to a roofing contractor, there are instances where outbuildings are only
highlighted on these site plans and omitted from architectural drawings. Overlooking such details will lead to unexpected costs.
Large and small construction projects rely heavily on detailed and organized documentation to ensure efficient and accurate execution. One of the cornerstones of this documentation is construction drawings, which act as a roadmap for contractors,
architects and clients alike. Let’s look at different construction drawings, interpreting their purpose and importance as they relate to the real world of building design and construction.
Construction drawings ensure that projects proceed efficiently by minimizing expensive and time-intensive
modifications. They can be segmented into five core categories:
1. Preliminary drawings
2. Presentation drawings
3. Working drawings
4. Shop/assembly drawings
5. Detail drawings.
Preliminary Drawings: These are early-stage schematic designs used for initial discussions between the designer and the client. Not for construction, they facilitate iterative refinement to finalize the design. They also guide preliminary decisions about systems, materials, costs and potential construction approvals.
Presentation Drawings: Aimed at showcasing the proposed structure in its envisioned setting, these are promotional and typically offer colored, detailed views. This phase finalizes the schematic design based on client approval.
Working Drawings: Essentially the construction blueprints, these technical documents provide extensive information
on building components. Functions include:
■ Acquiring building permits
■ Guiding competitive bidding
■ Providing construction directions
■ Assisting in material estimates
■ Serving as a long-term record and basis for contracts.
Letter codes usually organize blueprint sets:
■ A: Architectural
■ S: Structural
■ P: Plumbing
■ M: Mechanical
■ E: Electrical
For instance, a 30-page blueprint might be structured as A1-A8, S1-S10, P1-P3, M1-M4 and E1-E5.
Shop and Assembly Drawings: Drafted by contractors and suppliers, these detail how specific products or components will be fabricated and assembled. Often, specialists provide exact specifics about their components and approval precedes fabrication. These drawings ensure components fit perfectly within the larger construction.
Detail Drawings: These focus on particular construction elements and are more magnified than general ones. They illustrate facets not adequately covered in primary plans or elevations. Details clarify intricate parts of the design, like wall flashings, copings and gutters and are drawn to scale, often presenting several details on a single sheet.
Navigating the intricacies of construction documentation is paramount for roofing contractors. The following sections delineate the various plans and drawings crucial for accurate estimation and seamless execution in roofing projects.
A site plan, also known as a plot plan, offers a scaled representation of a property, illustrating its size, configuration
and features like buildings, driveways and walkways. Such plans depict existing features alongside proposed enhancements. Their primary objective is to present the building’s position relative to site boundaries, utilizing dimensions based on the foundation’s size. Notably, dimensions on site plans use feet and hundredths of a foot rather than the feet-and inches format used in architectural drawings.
The demolition plan is vital when projects arise on sites with pre-existing features not part of the final design. For roofing contractors, this plan indicates roof sections designated for removal or those requiring integration with existing structures.
These drawings provide extensive details about the structure’s components. They showcase the size, material, placement and interconnection of structural elements, encompassing foundation, floor, framing plans, elevations, details, schedules and bills of materials. Dimensions are precise and comprehensive, presenting both exterior and interior measurements. For minor projects, notes within the drawings can act as specifications.
Roof Plan: Contains roof-specific data. Projects may have multiple roof plans, depending on size and levels.
Floor Plan: Cross-verifying roof drawing measurements against this plan, which features dimensions provided by architects or engineers, is crucial. Roof plans are often found to have an incorrect scale on them.
Exterior Elevation: Illustrates building sides, detailing materials, building heights and roof pitches.
Building Cross Section: Offers insights into the structure as if it were sectioned vertically, revealing details from roof to foundation.
Shows the building’s support framework. These drawings lay out how the structure will bear and distribute its weight. They include foundation, floor and roof plans but emphasize structural details.
Structural Notes: Highlight roof zones and wind-uplift requirements.
Roof Framing Plans and Details: Specify if the structure is flat or sloped, essential for tapered insulation requirements. Other key details, like exterior and wall framing details and roof penetrations, are also outlined.
The lead sheet for mechanical drawings provides notes, legends and details. This plan delineates the mechanical system design, ductwork layout and equipment placement.
Roof Level Mechanical Plan: Pinpoints mechanical roof penetrations and items like cooling tower piping.
Mechanical Details: Exhibits rooftop penetration specifics.
HVAC schedules, crucial for roofing estimators, cover air-handling and fan-coil units. These schedules help determine the quantity and size of package units, including those on the rooftop that architectural plans might miss.
These drawings offer a comprehensive view of a project’s plumbing design, including line dimensions and locations.
Roof Plan: Displays drain patterns and sizes.
Riser Schedule: Indicates the size and count of vent pipes breaching the roof. If gas pipes exist on projects that penetrate the roof, they’re usually presented here.
The culmination of working drawings typically comprises the electrical plans, depicting the building’s electrical and communication systems. For roofing contractors, these drawings are vital for discerning rooftop lightning protection systems and other electric components that necessitate flashing details or roof penetration. As we’ve delved into the intricate details of various construction drawings, from the foundational site plans to the nuanced electrical layouts, it becomes evident how interconnected and essential each facet is for the roofing contractor. In the ever-evolving realm of construction, roofing
contractors are responsible for creating durable and effective roofing systems. Achieving this requires an astute understanding of many construction documents, from site plans to electrical drawings. With the multifaceted nature of modern projects, overlooking even a minor detail can lead to unforeseen complications and costs. Therefore, the ability to decipher and
integrate insights from diverse construction drawings becomes an invaluable asset. As the industry continues to advance, embracing this comprehensive approach ensures not only the structural integrity of our roofs but also fortifies the reputation and professionalism of roofing contractors. In essence, mastery over these documents is more than just a skill, it’s a testament to the dedication of members in the roofing industry and our commitment to excellence.
John Kenney, CPRC has over 50 years of experience in the roofing industry. He started his career by working as a roofing apprentice at a family business in the Northeast and worked his way up to operating multiple Top 100 Roofing Contractors. As CEO, John is intimately familiar with all aspects of roofing production, estimating and operations. During his tenure in the industry, John ran business units associated with delivering excellent workmanship and unparalleled customer service while ensuring his company’s strong net profits before joining Cotney Consulting Group. If you would like any further information on
this or another subject, you can contact John at jkenney@cotneyconsulting.com.
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