Have you ever driven buy a new home site and seen a freshly-poured foundation, with a lot of stubby pipes sticking out? There's a lot of important business hidden inside that foundation. A lot of planning goes into the preparations under your foundation. It's called Ground Plumbing, and the plumbers have a lot of precise work to do at this early stage. Before you pour the concrete for the foundation of your new house, you have some very important choices to make. We'll show you what goes on underneath the foundation, we'll show you why things are sticking out of the ground in specific places instead of a couple of inches right or left, and we'll point out a couple of essential decisions you should make now, so you don't waste your time and money later.

Plumbers first measure and mark pipe placements - The plumbers start with a set of plans, and measure precisely the locations for your fixtures (sinks, tubs, toilets), stacks (main pipes), and walls (so they can hide pipes within). They mark these measurements on the wood form boards that will eventually contain the concrete poured to create your foundation.

Plumbers dig trenches - Once the plumbers know where to run their lines, they roll out a small trench-digger and dig trenches for the main lines. If they run into hard rock beneath the surface, as we saw in the home site we featured, they'll have to roll out a back-hoe for some serious digging.

Plumbers run sewer lines - Once the trenches are dug, the plumbers run PVC pipe to create the drainage system for your house. They rely on gravity to drain sewage away from the house, so all lines run at a slight downward angle from the house to properly drain into the sewer lines.

Plumbers loop copper water lines - They use soft, bendable copper tubes so no joints exist within the concrete. Then they solder them shut above the eventual level of your foundation slab. They place a blue sleeve around cold water lines, and red sleeves around hot water lines. When concrete comes in contact with metal, it creates a chemical reaction called electrolysis that could eventually eat away at the copper tubing. So in addition to identifying hot and cold lines, the sleeves protect the sections of the copper tubing that will eventually be encased in concrete to make sure the copper never actually touches the concrete and sets off this reaction.

Plumbers dig & connect to city sewer & water lines - They call these yard lines or service lines. This is the stage where they tie in to the main lines provided by the city and the developer. One line feeds water into your house; the other line drains water & sewage away from your house into municipal sewer lines.

Pressure testing - The plumbers will "stub out" the pipes so they stick out at least 4' above the eventual level of foundation concrete. Different regions utilize different pressure tests, but the goal is the same. They want to make sure before they encase all this plumbing work in concrete that none of your pipes will leak.

Water Test - First they tap into your main water line and fill all your pipes with water. The 4' of vertical water in the pipes will create a gravitational pressure in the system of still-exposed pipes. About a day later, an inspector will check for leaks and wet spots on the ground.

Air Test - In this approach, the plumbers will seal off all pipes and pump air into the system to create a specific pressure level. A day or two later, inspectors will measure the remaining pressure, compare it to the initial pressure and determine if the system contains any leaks that must be plugged before your foundation is poured.

Critical Points for Homeowners - You may not get directly involved in the ground plumbing process, but a lot of your decisions and desires will have a direct affect on the ground work the plumbers do as they start to work on your house. The plumbers must be precise when they place pipes and fixtures because most of their work needs to be hidden inside the walls of your house, which are usually no thicker than 6".

If you're building a home, you need to think now about how many sinks and tubs and toilets you want, and exactly where you want them in the kitchens or bathrooms. We featured a home site which will include a free-standing island in the kitchen, complete with a sink. That's a great amenity, but it means that the sink will not be attached to a wall, as most sinks are. So the plumbers have to run special lines just for that sink that'll run down into the floor, over to the nearest wall, then up and out like the other fixtures. You can see why planning ahead is so crucial.

If you're thinking about a wet bar in a family room, decide now, or else you'll spend a ton of money digging up the concrete to re-route the plumbing after the house is built to accommodate that wet bar. What kind of bathtubs will you have in the bathrooms? Which end will they drain from? Or do you want to get one of those nice big tubs that drain from the middle? The answer determines where the plumbers place your fixture connections now, so you need to make those decisions now.

If the plumbers design a drainage system in your bathroom for a standard tub (the kind that drains from one end or the other), and you've got your heart set on a spa tub with a drain in the center, then the drainage connection will be off by a few crucial inches. So you'll either get your heart broken or your concrete foundation broken to correct that mistake. Once the system passes the pressure test, the entire network of piping is covered with sand and dirt to cushion the pipes from the weight of the concrete that will encase them.

We've reached the moment of truth. Now that the system has passed the pressure test, the next step is pouring the concrete for the foundation, so make sure you've planned ahead. Once that concrete dries it will cost you a lot of money and a lot of aggravation to dig back in and make changes. Work with your builder now to make sure you have the fixtures you want where you want them, so you never have to think again about all the hidden business under your new house.

Contact Information:
Accent Plumbing
Residential & Commercial Plumbing
972-564-1821