Plumbing Basics

The plumbing design should already have been created in the building plans and specifications for your small house. The next step is to decide what kind of materials will be needed to construct the plumbing and the quantity needed to complete the job.

There are two main concepts to consider with regard to plumbing basics and constructing a properly functioning plumbing system. The supply lines allow access to fresh water and the waste lines dispense of used water into the septic system.

There are a few things to consider when setting up the supply and waste lines which include determining the pitch of the waste lines. The National Plumbing Code which your local plumber uses as a guideline will help in this decision as well as the building plans of your small house.

As a general rule the pitch of the waste lines require at least a 4% grade in order to allow both solids and liquids to drain out of the system. If the pitch is too steep, the liquid will drain away but the solids will get lodged in the piping. If the pitch is not enough, you will be constantly dealing with clogging causing you to frequently flush out the system.

With regard to materials for construction for supply lines which allow access to fresh water, the three basic types of piping that are used is copper, galvanized, or pvc. A newer material frequently being used in new houses is pex tubing which is much more flexible and easy to work with when constructing the plumbing system. The only drawback being the fittings and attachment units can be somewhat pricey.

Galvanized piping is usually found in old houses but is also still used in current houses due to the fact that the water runs through this type of piping more quietly. It tends to corrode faster than copper piping which is the reason for the conversion over the years to copper or pvc piping in addition to other factors such as cost.

It is extremely important to make sure the waste lines are designed and set up properly. These lines require cast iron, galvanized, or ABS (Acrylonitrile Butadiene Styrene) piping. Like pex piping, ABS is the newest form of piping for wastewater systems. It is cost effective and easier to work with during construction of the plumbing system.

The waste water lines must contain a trap at sinks, tubs, and toilets to prevent sewer gas from coming back into the house. Additionally, the lines must contain a T-line that runs downward and up to the roof. The line running to the roof provides added ventilation as well as relief from the vacuum effect that can occur from a single line running downward. A “T” clean-out fitting should be present at points throughout your plumbing system to allow for cleaning and flushing in the event of a clog.

This information will offer you the plumbing basics or as an introduction to “plumbing for dummies” to get you pointed in the right direction and also if you are considering a do-it-yourself plumbing project. The only plumbing I attempted was trying to hook up the drain lines from the kitchen sink. When the regular subcontracting plumber took a look he ended up taking it apart and redoing the whole thing. The lesson here is if you are in doubt; hire a certified plumber for your small house project, especially when it comes to the wastewater line.

Pictures From Our Small House

No, this isn't "Joe the Plumber".

Plumbing for the shower tub.