Plumbers in Venus, Texas

Why anyone waters a foundation

Clay shrinks when it dries and swells when it wets. A slab sitting on it moves with that cycle, and the damage comes from the edges drying out faster than the middle, so the perimeter drops while the centre stays put. The aim of watering is not to soak the ground. It is to keep the moisture at the perimeter roughly constant so the difference never gets large.

That framing decides everything else. Little and often beats a long soak. Consistency through the dry months beats a panic in August. And the objective is even coverage all the way round, because watering three sides of a house and not the fourth creates exactly the differential you were trying to avoid.

Done badly, it does harm. Water pooled against the slab saturates one spot, and saturated clay swells. That lifts a section of perimeter, which is the same damage as drying, just in the other direction.

Setting it up properly

Distance from the slab. The hose wants to be somewhere around a foot to eighteen inches out, not tight against the concrete. Against the slab, water runs down the face and saturates a narrow band. Out too far and you are watering the lawn.

Soaker hose, not sprinkler. Soaker delivers slowly and evenly into the soil. A sprinkler throws water at the wall, the windows and the beds, and most of it evaporates before it does any good.

A timer, and short frequent cycles. Fifteen to thirty minutes in the early morning, several times a week in dry weather, rather than two hours on a Saturday. The soil can only take water at the rate it can absorb it.

Split the run. One long soaker around a whole house delivers far more at the start than at the end. Two or three zones off a manifold, each a manageable length, give you even coverage and let you skip the shaded side that never dries out.

Watch what happens in rain. A timer that keeps running through a wet week is doing damage. Either switch it off manually or fit a sensor.

The plumbing side people miss

Everything above hangs off a hose bib, and that tap is now running unattended for hours a week through the hottest months.

It needs a backflow device at the tap. A hose lying in wet soil, with the tap open and a pressure drop in the street, is a route for ground water into your supply. A vacuum breaker is a few dollars and it belongs on any bib with a permanent hose attached.

The tap itself also wears differently under this duty. A bib that gets used twice a year lasts decades; one carrying a timer all summer will start weeping at the stem, and a weeping bib on an exterior wall is how water gets into a wall cavity.

Then there is the bill. A watering programme uses a real volume of water, and on a house where sewer charges are calculated from water use it is worth knowing whether your supplier bills that way. Where it matters, a separate irrigation meter can be worth pricing.

Last, the thing we get called about most: telling foundation movement from a leak. A slab leak also wets the ground under a house, and it also causes movement. If the ground on one side stays damp when nothing has been watered, or the water bill has risen without a change in habits, that is not a foundation question. Check the meter with everything off before you conclude anything else.

How we work on these

We will set the whole thing up as a proper installation: a dedicated bib with a vacuum breaker, a timer, a manifold and zoned soaker runs at the right offset, in a morning. And if the concern is that something is already leaking under there, we would rather test for that first, because there is no sense watering a foundation that is being watered from below.

If you are already working with a foundation contractor or an engineer, we are happy to do the plumbing tests they ask for and send the results straight to them. A hydrostatic test result in an engineer's hands is worth more than the same result described over a fence.

Venus, Alvarado, Midlothian and Grandview are on our route, and we will tell you honestly if what a foundation company has recommended is more watering than this soil needs.