Drainage and leveling questions

We are based in Pflugerville and work across the suburbs north and east of Austin. That includes Round Rock, Hutto, Manor, Georgetown, Taylor, Elgin, Wells Branch, Brushy Creek, Cedar Park, Leander and northeast Austin. Most of these towns sit on heavy clay soil, which is why drainage and sinking concrete come up so often here. If your address is between two of these towns, or just outside them, call and ask. We will tell you if we can reach you.

A surface drain catches water that is already sitting on top of the ground. It uses a grate, such as a catch basin or channel drain, connected to a solid pipe that carries the water away. A French drain is a trench filled with gravel and a perforated pipe. It collects water that soaks into the soil and moves it downhill underground. Surface drains are best for puddles, patios and downspouts. French drains are best for ground that stays soggy. Many yards need a mix of both.

On clay soil, the most common reasons are a flat or reversed grade, low spots that formed as fill soil settled, and clay that soaks up water very slowly. Downspouts that dump right next to the house add a lot of water to one small area. Sod laid on compacted builder fill, or a neighbor's yard that drains onto yours, can also be part of it. Watch where the water comes from during a storm and where it sits afterward. That tells you a lot about which fix fits.

Often, yes. A simple extension that drops water several feet from the house on ground that slopes away is a cheap and effective first step. The trouble is that above-ground extensions get kicked, mowed over and moved, and they can cross walkways. Underground downspout drains carry roof water through a solid pipe to a pop-up emitter or other outlet farther from the slab. They make more sense when you need to move water a long way or when extensions keep getting in the way.

Be careful here. Texas Water Code Section 11.086 says a person may not divert or impound the natural flow of surface water in a way that damages another person's property by overflow. A neighbor who is harmed can seek damages in court. In plain terms, you should not change your yard so that it sends new or concentrated water onto a neighbor. A good drainage plan keeps water on a path to the street, an approved outlet or a natural drainage route. For a dispute, talk to a lawyer. This is not legal advice.

Yes. Texas law requires anyone digging to notify the Texas811 one-call center before the work starts. Under current state rules, notice generally must be given at least 48 hours ahead, not counting weekends and legal holidays, and no more than 14 days ahead. Utility owners then mark their buried lines with paint or flags. Private lines, like sprinkler pipes or a line to a backyard light, are usually not marked, so plan around those too. Check Texas811 for the current rules before you dig.

It depends on where you live and what the job involves. Many HOAs in the Pflugerville and Round Rock area ask for approval before changes to grading, landscaping or anything visible from the street. Some cities have rules about drainage easements, outlets at the curb and changing the grade along a lot line. Work inside a drainage easement may need city sign-off. The rules differ from one city and HOA to the next, so check with yours before the work starts.

Sometimes, but it needs care. A dry well is a buried chamber that holds water and lets it soak into the ground slowly. Heavy clay soaks up water very slowly, so a dry well on the Blackland Prairie may fill and stay full during a long rain. It can still help with a small amount of roof water, especially when it is sized well and the soil is tested first. Where the yard has enough slope, sending water to the street or a swale is often more reliable in clay.

A pop-up emitter is the outlet at the end of a buried drain line, often used with underground downspout drains. It sits flush with the lawn. When water flows through the pipe, the pressure pushes the small lid up and the water spills out onto the grass. When the flow stops, the lid drops back down. It should be placed where the ground slopes away toward the street or a swale, well away from the slab and not aimed at a neighbor's yard. Keep grass and dirt from building up over the lid so it can open.

Both lift a sunken slab by pumping material underneath it. Mudjacking uses a heavy cement and soil slurry pushed through holes that are usually an inch or more across. Foam leveling uses polyurethane foam injected through much smaller holes, often around 5/8 of an inch. The foam weighs only a few pounds per cubic foot, while slurry weighs far more, which matters on soft or expansive soil. Foam usually cures in minutes to hours. Slurry often needs a day or more. Foam generally costs more per square foot.

Most flat outdoor slabs are good candidates. That includes driveway panels, sidewalks, front walks, patios, pool decks and garage aprons. The slab needs to be in one piece or in a few large pieces. Concrete that is broken into many small chunks, badly crumbling or heaved up by tree roots may need to be replaced instead. Leveling also works best when the cause of the sinking, often water washing out the soil underneath, is fixed at the same time.

Concrete sinks when the soil under it loses support. On clay ground, that often happens when the soil shrinks during drought and leaves gaps, or when water from a downspout or a leaking joint washes soil out from under the edge. Fill soil placed during construction can also settle over the first few years. Patios that sit under a roof edge with no gutter take a lot of water. Finding the reason helps the lift last longer, because the same cause will keep working on the slab if it is left alone.

No one can promise a set number of years, because it depends on what caused the sinking. Polyurethane foam does not wash out the way loose soil can, so the material itself holds up well. But clay keeps shrinking and swelling with the seasons. If water keeps pouring onto the area, or the soil keeps drying out deep below, the slab can move again. Sealing the joints and fixing the drainage around the slab are the best ways to help a lift hold.

On clay soil, it is usually worth it. The joints between driveway and sidewalk panels are there on purpose, so the concrete can crack in a straight line instead of at random. But an open joint also lets rain run straight down into the soil under the slab. Over time that water can wash out fine soil or make the clay swell in one spot. A flexible sealant made for concrete joints keeps most of that water out while still letting the slabs move a little. Sealing right after a slab is lifted helps protect the lift.

Much of the land east of I-35, including Pflugerville, Hutto and Taylor, sits in the Blackland Prairie. Its dark clays, such as Houston Black, have a very high shrink-swell potential. When they get wet they swell, and when they dry out they shrink and crack. Clay also lets water soak in very slowly, so rain tends to run off or puddle instead of draining. That swelling and shrinking can tilt sidewalks, sink patios and stress slabs. Even, steady moisture and good drainage help limit the movement.

No. We do not do structural foundation repair, such as piers or lifting the house itself. Our work is drainage and leveling outdoor flatwork like driveways, walks and patios. If you see signs of foundation movement, like new cracks in brick or drywall, doors that stick or a sloping floor, have a structural engineer or a foundation repair company look at it first. Once that is sorted out, good drainage helps protect the foundation by keeping soil moisture around the slab more even.

Many engineers and foundation companies in Central Texas suggest it on expansive clay. When the soil next to the slab dries out and pulls away, it can let the edge of the house settle. Watering keeps the moisture more even, but too much water causes swelling, which is also a problem. The usual advice is to water a little way out from the slab, not against it, and to water evenly all the way around. Follow any watering limits from your city or water utility.

A slab on clay does best when the soil under and around it stays at a steady moisture level. When roof water dumps in one corner or puddles along one wall, that side swells while the rest stays dry. The uneven movement puts stress on the slab. Sloping the soil away from the house, carrying downspout water out into the yard and draining low spots all help keep the moisture more even. Drainage cannot fix a foundation that has already moved, but it removes one common cause of movement.

Yes, in general. West of roughly I-35, the ground moves toward the limestone hills at the edge of the Edwards Plateau. Many lots in Cedar Park and Leander have thinner soil over rock, with pockets of clay in between. That means digging can hit rock, and water may run across the surface instead of soaking in. East of I-35, the deep black clays of the Blackland Prairie are the bigger concern. Conditions can change from one street to the next, so each yard needs its own look.

We cannot give a price without seeing the yard, but national cost guides give a sense of scale. They often list roughly $10 to $65 per linear foot, with typical yard trench drains toward the middle or upper part of that range. The final number depends on the length of the run, how deep it needs to go, rock in the trench, the outlet, how much sod or concrete has to be removed and replaced, and access for equipment. Treat any online figure as a rough range, not a quote.

We walk the property with you and ask where water collects and when. We look at the roof edges, gutters and downspouts, the grade along the slab, low spots, neighbor runoff and where water can legally leave the lot. We often use a level or laser to check slope. For concrete, we look at how far the slab has dropped and why. Then we explain what we found and give you a written estimate with the options that fit your yard.

Small jobs, like burying a few downspouts or leveling a couple of sidewalk panels, often take a day or less. Longer French drains, full regrading or several drain types together can take a few days. Foam-leveled concrete can usually be walked on soon after the work is done. Before any digging starts, there is also the 811 waiting period, and some jobs need HOA or city approval. Wet clay is hard to work, so heavy rain can push a start date back.