Sewer pipe lining for Atlanta lateralsa new pipe inside the old one

A cured-in-place liner starts as a flexible tube of felt or fibreglass material, sized to the inside of the pipe being repaired. Just before installation it is saturated with a resin, commonly an epoxy or similar thermosetting resin for residential laterals. The wet tube is then put into the old pipe, either by turning it inside out as it is pushed in with air or water pressure, a method called inversion, or by pulling it into place and inflating a bladder inside it ^[1].

Pressure holds the tube tight against the walls of the old pipe while the resin cures. Depending on the system, curing is driven by hot water, steam, ultraviolet light or simply time at ambient temperature. Once cured, the resin and fabric form a rigid, continuous pipe that fits snugly inside the old one, with no joints along its length ^[1].

The old pipe stays where it is and acts as a host and a form. The liner does not depend on it for strength in the way a coating would, but it does depend on it for shape. If the host is round and runs at a steady slope, the liner will be round and slope the same way. If the host is collapsed, deformed or sagging, the liner will reproduce those problems.

On a residential job the liner usually runs from a cleanout near the house to the connection with the public sewer, or to a pit dug at the far end of the section being lined. For lines with only one or two bad spots, short sectional or point liners can be placed at individual defects rather than lining the entire run.

Vitrified clay is a hard, chemically resistant pipe material, and clay sewer pipe can stay structurally sound for a very long time ^[2]. The weakness of older clay lines is not the pipe body but the joints between short sections. Over decades, those joints loosen, roots find them and soil movement opens them a little more each year.

That combination is extremely common in Atlanta. Intown neighborhoods such as Virginia-Highland, Kirkwood and Grant Park were largely built in the late 1800s and early 1900s, and the city is famous for a dense tree canopy ^[3]. A clay lateral there may have thirty or more joints between the house and the street, many of them hosting roots.

Lining treats the whole problem rather than its symptoms. Instead of cutting roots at every joint again and again, or digging up the worst ones one at a time, the liner covers all of them in one installation and leaves a smooth, jointless pipe.

Cast iron under older houses is the other common candidate. Its interior corrodes and builds up scale that narrows the pipe and snags debris ^[4]. After the scale is removed, a liner can close pinholes and restore a smooth bore.

Expect an inspection visit before the lining day. The contractor will want footage of the whole line, a measurement of its length and diameter, and a plan for access. If you already have recent footage from another contractor, mention it on the call.

On the day, the work concentrates at the cleanout and any pit. There may be a truck with resin equipment, a hot water or steam unit, or an ultraviolet light train, depending on the system the contractor uses. The house cannot use its drains while the line is being cleaned, lined and cured, so plan showers, laundry and dishwashing around the schedule the contractor gives you on the call.

When the liner has cured and the connections are reopened, ask to watch the final camera run or receive the footage. You should see a smooth, continuous pipe with no wrinkles that block flow, clean ends at the house and street, and open branch connections.

Ask how the access pit will be backfilled and compacted, how the surface will be restored, and what records you will receive. The contractor you are connected with is independent; the scope of work and any guarantee are agreed between you and them.

Lining is especially useful where the ground above the lateral is hard to disturb. In historic districts such as Inman Park and West End, front yards often have stone retaining walls, granite steps and original walkways. A liner installed from a cleanout and a small pit near the street can leave those untouched.

Atlanta's canopy is another reason. A trench through the root zone of a large oak can harm the tree; a liner leaves roots between the access points alone. Where a lateral runs under or near a significant tree, ask the contractor to place the access points away from the trunk.

Red clay subsoil, common across the Piedmont, is dense and sticky ^[7]. It makes small pits stable but slow to dig and harder to compact properly afterwards. Good compaction at the pit prevents settling later.

Where the liner needs to end at or near the public sewer connection, the work may involve the sewer utility. Inside the City of Atlanta that is the Department of Watershed Management; in Brookhaven and other DeKalb County areas outside the city, it is DeKalb County's watershed department.

Lining and replacement solve different problems. Lining is strongest where the pipe's shape and slope are good and the trouble is in its joints and walls. Replacement is stronger where the shape or slope is gone: collapses, deformed fibre pipe and bellies that hold water.

Many real lines are a mix. A common Atlanta plan is a short spot repair at a collapsed section or a sag, followed by lining the rest of the run once the path is clear. If one contractor proposes lining and another proposes replacement, ask each to point to the footage that rules out the other approach. Our trenchless vs excavation guide sets out the trade-offs in more detail.

Lining stops roots entering through joints, closes cracks, ends groundwater infiltration and smooths a scaled interior. It does not fix a sag, a collapse, an undersized line or problems inside the house, such as a failed vent or a dry trap that lets sewer gas into a room.

If roots are the reason you are looking at lining, the root intrusion removal page explains the clearing step that comes first, and the tree roots in the sewer line guide covers the warning signs.

A full-length liner is strongest in the middle and most vulnerable at its edges. At the house end it meets the building drain or a cleanout fitting, often a different material and sometimes a different diameter. At the street end it stops at or near the connection with the public sewer. If either transition is rough, unsealed or leaves a lip, debris can catch there and roots can find the small gap between the liner and the old pipe.

Good installers pay attention to these points. They trim the liner cleanly, make sure it sits tight to the host pipe, and in some systems add end seals or short sleeves that bridge the transition. On the final camera run, look for a smooth step from old pipe to liner, no fraying fabric and no ledge across the bottom of the pipe where water runs.

If symptoms ever return after lining, the ends and the reinstated branch connections are the first places a camera should look. Most liner problems that appear years later start at one of them rather than in the body of the liner.

More older Atlanta houses now come on the market with laterals that were lined by a previous owner. If you are buying, a sewer camera inspection will show the liner clearly: a uniform, smooth interior with visible transitions at each end. Ask the seller for any records of the work, including the original footage, the length lined and who did it. If you are selling a house with a lined lateral, gather those records before listing; they answer a buyer inspector's questions quickly and show that a known problem was dealt with rather than hidden.