New Construction Plumbing in Cumming, GA

On a house built on a concrete slab, part of the new construction plumbing is fixed permanently before a single wall exists. Every toilet flange, shower drain, tub trap and floor drain on the ground floor begins as a pipe poking out of gravel, waiting for concrete. Get those positions right and the rest of the house fits around them; get one wrong and the fix involves a saw. For slab homes in Cumming, this stage deserves more planning than any other.

Laying out drains from the plans

Under-slab layout starts with the architectural plans and the fixture selections. Each drain is located from the foundation lines, with allowance for wall framing and the finished surfaces that come later. A toilet needs its flange at the right distance from the finished wall behind it, a shower drain has to land where the tile layout expects it, and a freestanding tub needs its drain directly under the tub's outlet, which varies by model. Measuring from the slab forms rather than from rough guesses keeps every point where it belongs.

Slope, sleeves and cleanouts

Beneath the stubs, branch drains run to the building drain with a steady fall toward the spot where it leaves the house. Where pipe must pass through a footing or grade beam, the structural design determines the opening and support. A suitable sleeve provides clearance and protects the pipe from contact; it does not by itself make an arbitrary opening structurally safe. Cleanouts go where the layout needs them and where a future drain cleaner can actually reach them, preferably not beneath a kitchen cabinet. The finished underground system is then filled for its test.

Protecting the pipe during the pour

• Stubs are capped and taped so concrete and gravel stay out.
• Tub drains usually get a box-out, a small form that leaves a pocket in the slab for the final connection.
• Pipe is anchored so the concrete crew's raking and screeding cannot shift it.
• Someone from the plumbing side rechecks positions just before the pour, after the vapor barrier and reinforcement are down.

Testing before the pour

The finished under-slab system is filled for its test and checked while still exposed. Call for the check once the test is holding, not once the pour is scheduled, so a correction can be made before the concrete truck is booked.

The sewer connection

The building drain leaves the slab and becomes the building sewer, which runs out to the public main. Confirm with the sewer provider who makes the tap and how much lead time it needs, well before the trench is opened. Where an older lateral from a previous building is still on the lot, a sewer camera inspection shows its visible condition, which helps decide whether any of it can be reused.

Why mistakes here cost more

Once concrete cures over a drain, correcting it means cutting out slab, digging to the pipe and patching the floor. That is the kind of work our drain excavation crew performs on existing homes, and it is far easier to avoid on a new one. A careful layout check before the pour takes an hour, while moving a misplaced shower drain afterward can take days. On our new construction plumbing jobs, that pre-pour check is a fixed step.

Slab plumbing questions for Cumming homes

Can a drain location change after the slab is poured?

It can, but only by cutting the concrete, rerouting pipe underneath and patching the slab, which also means retesting and rescheduling the other trades. Small shifts are sometimes possible with offset fittings at the fixture. For anything larger, the sensible course is to settle locations before the pour and confirm them against the fixture you actually bought.

What is a box-out in a slab?

A box-out is a small form placed around a drain, usually for a bathtub, so the concrete leaves an open pocket instead of encasing the pipe. It lets the plumber connect the tub's drain assembly later at exactly the right height and position. Once the tub is set and connected, the pocket is finished off as the tub manufacturer directs.

Planning a slab home

If your Cumming home will sit on a slab, bring us in before the forms go up. Call (404) 409-4448 and we will go over the under-floor layout with you.