Project planning is crucial for successful plumbing projects, so it is important to take the time to carefully map out all aspects of the project. The first step in project planning is defining the project scope. This involves identifying what needs to be done, for whom, and why. Residential and commercial plumbing projects will differ in scale and complexity. Commercial projects often involve larger systems and more extensive planning and design. Once you have a clear understanding of the project scope, you can begin to develop a plan that addresses all aspects of the project.

The person responsible for managing the organization of the plumbing project could be a single plumber on site or, on larger projects, there could be a dedicated plumbing project manager.

In either case, the individual will be at the very least responsible, to varying degrees, for:

• Project specifications
• Sequence of operation
• Prioritization
• Coordination with other trades
• Material estimates
• Tools and equipment
• Materials deliveries
• Inventory requirements
• Cost efficiency

Project Specifications

Construction drawings focus on a building’s shape, appearance, and dimensions, while the written construction specifications (or specs) focus on what materials will be used and how they should be installed. Which information goes into the notes on the drawings and which goes into the specs is up to the designer, but a good set of detailed specs goes far beyond what could possibly be put onto a drawing. It is acceptable for the same information to appear in both places, but if there is any contradiction, the specifications generally take priority from a legal standpoint.

Project specifications (specs) detail the performance requirements of the installations. The specification documents are the:

• Technical requirements for materials and equipment
• Standards of workmanship
• Requirements of testing and commissioning
• Requirements for document submissions for an installation

Sequence of Operation

Once the plumbing contract has been awarded, the authority having jurisdiction (AHJ) requires a plumbing permit to be issued before installing or altering any plumbing work. The permit requires periodic inspections after each phase of the installation. A logical sequence of operation used by mechanical contractors is to divide the project into three distinct phases with an AHJ inspection showing the completion of the individual phases:

• Groundwork inspection: required immediately after all underground piping has been installed and before placing any material on or over the pipes. At this stage, an air or water test is required before being approved by the inspector.
• Rough-in inspection: required after rough-in plumbing has been completed and before installation of any wall covering that would conceal the piping. At this stage, an air or water test is conducted.
• Final plumbing inspection: required after the system has been completed and all fixtures have been installed and are fully functional.

Prioritization

The ability of a contractor to prioritize tasks and meet project deadlines is extremely important. A logical approach to this skill is to break the project into a list of activities that fall into each construction phase. The prioritization of activities in the list can use the following lettering system, which shows what must be done immediately and what can wait:

• Mark the activities that MUST be done today with an A.
• Mark the activities that you SHOULD be able to do today with a B.
• Mark the activities that you HOPE to be able to do today with a C.
• Mark the activities that LIKELY WILL NOT be accomplished today with a D.

This logical approach has a number of advantages for your company and the general contractor (GC) who has hired you. If you demonstrate a professional, organized approach to the project, the GC is more likely to hire you again. The advantages of a well-prioritized approach are:

• Reduced construction time
• Reduced costs for materials, labour, and overhead
• A more continuous work flow
• A goal for crews and subs to work toward
• Increased productivity

Coordination with Other Trades

The success of a construction project depends on proper site coordination. The general contractor is responsible for ensuring that this requirement is achieved through regular on-the-job meetings with the general contractor’s authorized project representative and the onsite subcontractors.

Additional meetings may be required for subcontractors whose work might interfere with that of another at a given time during the project. The general contractor and each subcontractor should organize their own work so as not to deviate from the schedule nor to interfere with or otherwise adversely affect the work of others. The general contractor should monitor and coordinate the work of all parties to ensure compliance with the project schedule.

Estimate Materials

Installation estimates are based on the materials take-off (materials list). The materials list is used during two preliminary time periods of the project:

• Job estimate: the estimate or bid will only be as accurate as the take-off on which it is based. A properly made take-off shows everything necessary to enable a proper estimate for the installation. A full set of drawings and a set of specifications are needed for every materials list. If there are piping runs in three dimensions, begin by making an isometric drawing, which is the foundation for an accurate take-off. Another term used to describe a materials take-off is a quantity survey.
• Materials acquisition: the other function of the take-off is as the checklist for ordering materials. Any necessary materials overlooked by the take-off will not be on hand when you begin the installation. Time will be lost while you wait for the missing items. Therefore, it is very important that you can take-off materials accurately.

The isometric drawing is a valuable estimating tool because, from one drawing, you can estimate the required horizontal piping as well as the vertical risers, leaders, and stacks.

These vertical pipe sections are not represented to scale on a plan drawing. It is very important that the isometric drawing be to scale! Most isometric drawing sheets have [latex]\tfrac{1}{4}[/latex] in. isometric gridlines already printed on them, so if you scale the drawing to [latex]\tfrac{1}{4}[/latex] in. = 1 ft 0 in., then each grid box will represent one foot of pipe. If you construct the isometric drawing on paper without gridlines, use a scaling ruler to draw the system to scale. When scaling the lengths of piping, it is good practice to round up the lengths of pipe required to the nearest whole length. To stay organized when doing a DWV take-off, start at the top of the system and work toward the building sewer to avoid missing or duplicating material requirements.

Because there is so much material information that you take-off the drawings, it is best to use some kind of form to keep all of the information organized. A simple table, such as a DWV take-off worksheet (Figure 1), can be used as a starting point from which you create your own as your projects get more complex.

The fittings should be arranged according to size and type (Figure 2). Most constructed DWV systems use more fittings than what was estimated in the take-off. These extra fittings are largely elbows used in getting around obstructions. An allowance should be made for extra fittings that are over and above the total in the estimate. The actual percentage will be refined as you become more experienced, but it will be around 5% of the total counted.

A fixture and equipment take-off (Figure 3) is relatively straightforward because the location and required equipment will be shown on the plans or detailed in the specification. On larger projects, there would be a fixture schedule with numbers that correspond to locations shown on the plans. These numbers would also correspond to the specification that would give details about each fixture.

Once the material quantities have been established, the next step is to take the material take-off sheets to all of your suppliers (not just one) and compare the prices each supplier offers.

Tools and Equipment

Whether constructing small residential or large commercial plumbing systems, every contractor has asked the same question at some point: “Do I rent or buy the equipment I need for the project?”

Buying Equipment

Buying equipment to use in your residential or commercial construction project can offer several benefits:

• Equipment you own is always on hand.
• You never have to worry about scheduling a time to use it.
• You also can gain a lot of experience using your own equipment so that you will be able to finish your job more quickly.

Renting Equipment

There are many benefits to renting equipment, whether it is something small like a chipping hammer or something large like an excavator:

• You will only need to pay for it when you need it, with no huge upfront cost and no worry that you may never use it again.
• You will also be able to access new equipment and never have to worry about having to pay for maintenance, repair, or even replacement.
• Renting equipment also means that you will have a better selection of tools to choose from.

Material Availability

Material availability may influence material selection decisions. Long delivery lead-in times must be allowed for, as delays may cause project holdups. Using locally available materials reduces transportation costs, labour costs, probability of damage to the materials, etc.

If the required material is not available at the desired time, an unavailability cost is incurred. Shortages may delay work, thereby wasting labour resources or delaying the completion of the entire project. It is difficult to forecast in advance exactly when an item may be required or when a shipment will be received. If items are unavailable when needed, it may be possible to assign workers to other activities, avoiding delays to the project.

Timing/Sequencing

The site delivery of materials at the right time is essential to an efficient material-handling system. The use of just-in-time delivery has reduced the time a contractor has to hold inventory from days, weeks, and months to minutes and hours. For many job sites working on a tight schedule, if materials cannot be delivered on time, it is better to have them not delivered at all until delivery can be rescheduled. Being late will cause scheduling problems, and the job site may incur associated cost overruns.

Transportation

The heavier or bulkier the materials are, the greater the transportation costs will be. Where possible, try to purchase locally, especially for heavy and bulky items. This will help to keep transportation costs to a minimum. Damage to materials occurs mainly during handling. The condition of the material when it arrives on site is highly dependent on the handling system and the distance it has travelled to the site.

Inventory Requirements

Once goods are purchased, they represent an inventory used during the construction process. Inventory control is an operational strategy that means stocking adequate numbers and kinds of materials so that the materials are available when and where they are needed. To accomplish this, many contractors employ an advance purchasing practice.

Advance purchasing of construction materials and equipment is a practical procedure that saves money and promotes the on-time completion of construction projects. Plumbing contractors gain the full benefit of advance purchasing by allowing progress payments to include payment for materials and equipment stored at the construction site. Early delivery of materials and equipment also guards against escalating costs, particularly in long-term contracts, and enables the contractor and subcontractors to make timely purchases when shortages may be a problem.

Secure Storage

When using an early purchase strategy on your construction site, the secure storage of materials is essential. For progress payment purposes, store as much material within the footprint of the new building as possible. Material storage trailers or containers should be used to store three types of things:

• Tools
• Equipment that can be carried off easily or damaged by exposure to the elements
• Materials that are targets for thieves, such as copper

Store as much material as will be used by your crews inside the work site. Keep stores secure, dry, and organized because bad storage procedures can cause considerable waste.

Unless the contract clearly assigns the responsibility for protecting equipment and materials on site solely to security personnel, the plumbing contractor is usually responsible for the safe storage of all materials and equipment that they have stored or installed.

“Just-In-Time” Delivery

When storage on the actual construction site is impractical, the only other solution is to employ a just-in-time delivery strategy. One of the challenges with a new-build project is logistics. Many different flows of materials need to come together in a precise sequence, creating a highly complex building schedule. A small delay at the start can have big effects on the timing later in the project. Ideally, one would like to have all required materials stored on site so that contractors can be called in to do their part exactly when they are needed and do not have to wait for materials to be manufactured or arrive on site. However, in practice, this is sometimes impractical, as sites need to be kept to minimal size, especially in urban areas. Scheduling materials deliveries to the job site can become critically important on some projects and requires close cooperation between the contractor and the supplier.

Many contractors now make arrangements with their suppliers for their materials to be delivered at the exact time that they are required at the job site. Many suppliers favour this process because it may reduce their inventory, storage, theft, and handling costs and also allows for planning their delivery operations.

Labelling Materials

A materials list provides a format for keeping track of the materials needed on the job site. Organizing those materials in a box or bag ensures that they will be available when needed.

Identifying the organized materials is crucial for locating the correct stored items. If a material is not available when the storing process begins, a note should be made to remind the plumber that the stock list is incomplete. Items such as washer boxes and tub and shower valves are installed in two different phases. Therefore, the trim plates must be stored, protected, or even removed from the site until required for the trim-out phase.

Consumables

Consumables (also known as consumable goods, non-durable goods, or soft goods) are goods that can be consumed, dissipated, wasted, or spent. In plumbing construction projects, these may include materials such as solder, flux, sand cloth, fasteners, Teflon tape, and glue.

Many estimators do not take the time to list the quantities of these types of goods on their estimate. Instead, they just give the whole category a fixed price and add it to the job quote. For example, a plumbing contractor may cover the cost by charging $100.00 for consumables for an average single-family dwelling or $10.00 per fixture on larger projects.

Cost Efficiency

The main goal of any contractor is to achieve a high-quality installation on time and on budget. Construction industry research has shown that material-handling tasks consume approximately 40% of a plumbing contractor’s time — and time is money. Material handling is also recognized to be the single most common cause of unproductive time on the job. Any effort to significantly improve job-site productivity and profits can begin by addressing ways to reduce the lost time spent unnecessarily handling materials and equipment.

Plumbing project cost efficiency requires:

• Having adequate materials on hand when needed
• Paying the lowest possible prices, consistent with the requirement for quality and value for purchased materials
• Minimizing the inventory investment
• Operating efficiently

Post-job Efficiency Analysis

Project costs are measured and analyzed in many ways throughout a project — from planning, programming, and design to bidding, construction, turnover, and post-occupancy. First costs, cost-benefit ratios, and life-cycle costing are a few examples of how a project’s cost-effectiveness can be evaluated. These cost-management processes start with establishing budgets based on actual estimates for the work performed. Comparing budgets to actual costs throughout the building process is critical to ensuring that the project is timely and cost effective.

Self-Test D-2.4: Organizing a Plumbing Project

Complete Self-Test D-2.4 and check your answers.

References

Skilled Trades BC. (2021). Book 2: Install fixtures and appliances, install sanitary and storm drainage systems. Plumber apprenticeship program level 2 book 2 (Harmonized). Crown Publications: King’s Printer for British Columbia.

Trades Training BC. (2021). D-2: Plan DWV systems. In: Plumber Apprenticeship Program: Level 2. Industry Training Authority, BC.

Media Attributions

All figures are used with permission from Skilled Trades BC (2021) unless otherwise noted.