When you get a quote from a plumber it is very hard to keep track of the housing he uses and the amount of work being completed. Since you are not a plumber with years of experience under your belt, you need to have an estimate to know if the plumber is exceeding his quoted allotment of time. If he does surpass his allotted man-hours, he will likely charge you for it. Since you do not have years of quoting expertise, you must work with your plumber to estimate the necessary man-hours, and then you can use the agreed upon total as a guide to help you understand if he is completing the work on time.
Ask the plumber how long it takes to install a foot of pipe per the type of pipe you plan to install. For example, ask him how long it takes to install a foot of PVC pipe. Once you know the length of time, measure the length of pipe your project will require. Multiple the length of pipe by the total time.
Determine how long it will take the plumber to solder or couple each joint in the pipe work. Multiply this time by the total amount of joints you estimate you will have during the installation.
Ask the plumber how long it takes to complete the installation of the fixture you plan to have installed during the project. Multiply this time by the total amount of fixtures you plan to have installed. Fixtures includes, sink showers, bathtubs, toilets faucets and drains.
Add to the estimate any plans to complete the demolition and repair of any walls or floors to complete the installation. Often this is subcontracted. If your plumber does plan to complete these tasks, obtain a time frame.
Obtain the plumber's cost-per-hour rate and then multiply the rate by the combination of total hours planned for the job.