Drainage, French Drains, and Grading Correction

Most properties do not need one component, they need a route: somewhere for the water to be collected, a path for it to travel, and somewhere legal and lower for it to end. These are the pieces we build that route out of.

A driveway is a large impermeable surface, usually sloped, often pointing at a garage or a house. Whatever falls on it has to go somewhere, and if the grading was set carelessly, that somewhere is your garage slab or the base under the paving.

Water travelling under a driveway washes fine material out of the aggregate base. The base loses its support, the surface settles into it, and you get the depression, the alligator cracking, or the sunken paver field that prompted the call. Repaving without fixing the source produces the same failure in the same place on the same schedule.

On any driveway job we look at where water arrives and where it currently leaves, and price the correction openly. Sometimes that is a change of pitch during construction and costs almost nothing. Sometimes it is a trench drain across the apron tied into a piped run to daylight.

A patio that pools after rain has either lost its fall or never had it. On a paver patio the field can be lifted, the base corrected and recompacted, the grade re-established, and the same units reset — you generally do not need new material. On a poured slab the options are narrower, which is one of the arguments for pavers.

The other patio drainage problem is what happens at the edges. A patio that sits below the surrounding grade collects everything the lawn sheds, and the fix is interception — a French drain along the uphill side, or a channel drain across the point where water arrives — rather than anything done to the patio itself.

A retaining wall holds back soil, and saturated soil weighs dramatically more than dry soil and pushes considerably harder. Hydrostatic pressure behind a wall is the single most common reason walls lean, bulge, and eventually come down, and it is entirely preventable.

Every wall we build gets drainage aggregate behind it, filter fabric to keep the soil out of that aggregate, and a drain at the base running to an outfall. Weep holes through the face where the construction suits them. None of it is visible in the finished wall, which is exactly why it is the part that gets left out by whoever built the wall you are now asking us to look at.

A damp basement wall, efflorescence on the block, or a persistent wet patch beside the foundation is a drainage symptom before it is a waterproofing problem. The usual causes are grade that has settled back toward the house over the years, downspouts discharging at the wall, and a patio or walk that was built pitching the wrong way.

We start with the cheap answers, because they are often the right ones: extend the downspouts properly underground, re-establish positive grade for the first several feet out from the wall, and correct any hard surface that is delivering water to the foundation. Where that is genuinely not enough, a French drain along the affected side is the next step.

Most people call us about a surface — a driveway, a patio, a wall. A good proportion of those surfaces failed because of water, and rebuilding them without dealing with it means selling you the same job twice.

So we look at drainage on every estimate, we tell you what we find, and we price it as a separate line so you can see exactly what it costs and choose. Sometimes the honest answer is that your drainage is fine and nothing needs doing. We would rather say that than add a French drain to a quote to make the number look thorough.