Plumbing — it’s far from glamorous, but so important to our everyday lives. If you’re in the market to install plumbing on a property, you should be expecting to be trenching.
Planning the Path
Proper planning will make the rest of this project much easier. To do this right, you’ll need to get with your local utility companies to determine the locations of you water supply, your sewage outlet, and anything in the area that you need to watch out for, such as cable and electric.
Plan the pathway for your plumbing as efficiently as possible, but take into consideration other obstacles like tree roots and driveways. Sometimes these things can’t be avoided, and may require some demolition.
Preparing for Placement
To ensure a long lifetime for the plumbing, the trenches need to be dug to the proper depth and any rocks or other debris removed from the soil. That debris, if left in the soil, can cause damage to the pipes later as the earth moves and compacts and/or as the pipes expand and contract. This applies to both the soil at the bottom and sides of the trench, as well as the soil that will be used to backfill the trenches.
Generally, trenches for plumbing need to be dug to a depth that is twice the diameter of the pipes. Therefore, if you plan to use a piping with a 2” diameter, the trench needs to be about 4” deep. The width of the trench is more flexible, and is dependent on the installation crew having enough space to work within the trench.
As with any excavation, the trench for plumbing needs to have a well compacted base, so we strongly recommend that use a bedding material (such as sand) along the bottom of your trench, then use a mechanical compactor or tamper to compact everything and ensure a stable foundation.
Placing the Piping
Now that you have a solid foundation for your plumbing, the pipes can start going in. This is not an area where you want to skimp, so it is best to hire a professional company to ensure proper connections.
Before you backfill your project, there is one more layer—the haunch. This can be the same material that you used for your bedding layer, and it goes in around the pipes to keep them in place. This layer should also be carefully tamped down before the backfill soil is added over top.