Scottsdale gets little rain, but a large share of it arrives in a few violent storms. The ground under a slab can sit bone dry for months and then be soaked in twenty minutes. Most ground problems here come from that swing, or from irrigation doing the same thing slowly.
Do I need to worry about drainage?
Yes. Drainage matters more here than the low rainfall suggests. Hard desert soil sheds water instead of soaking it up, so a storm sends sheets of runoff across a lot. Every slab should fall away from the house, and the water needs somewhere to go: a swale, a drain or the street. Scottsdale reviews hardscape for stormwater for this reason.
My patio or driveway slopes toward the house. Can that be fixed?
Yes. A slab that tips toward the house can sometimes be lifted along the house side to reverse the fall. If it was built that way, the usual fixes are a channel drain cut in along the wall and piped to daylight, or replacing the slab at the correct slope. Do not leave it. Water standing against a stucco wall and slab edge leads to moisture indoors and soil movement under the footing.
Can tree roots crack or lift concrete?
Yes. Tree roots lift and crack slabs here much as they do anywhere, and desert watering habits make it worse. Trees on shallow drip or lawn irrigation keep their roots near the surface, right where the concrete is. Fast growers planted for shade, including some ficus and sissoo trees, are frequent offenders. Native mesquite and palo verde do less damage when they are watered deeply and seldom.
Can I fix the concrete and keep the tree?
Often, yes. To keep the tree, the lifted panel is removed, small roots are trimmed, and the new slab is poured a little higher, thinner over the root zone with extra steel, or rerouted around the trunk. A root barrier along the slab edge helps. Cutting large roots close to the trunk can end up killing the tree or leave it unstable in monsoon wind, so ask an arborist before any big cut.
My neighbor's new concrete sends runoff onto my property. What can I do?
Talk to the neighbor first and show them where the water goes in a storm. A small swale or a drain on their side often solves it. As a general rule, an owner may not change the natural flow of water in a way that damages the next lot, and Scottsdale's stormwater rules apply to hardscape. If talking fails, ask the city whether the work was approved, and speak to an attorney about your options. This is general information, not legal advice.
Does clay or soft soil change the job?
Yes. Clay swells when wet and shrinks when dry, and it is found in pockets across the Valley, most often on former farmland. Over clay we use a thicker compacted base, more steel and closer joints, and we keep irrigation away from the slab edge. Some desert soils have the opposite fault: they are loose and collapse the first time they get soaked. Those are pre-wetted and compacted before the pour.
What is caliche, and is it a problem?
Caliche is a layer of soil cemented by calcium carbonate, and it can be nearly as hard as weak concrete. It is common under Scottsdale. As a base it is excellent, because it does not settle. As something to dig through it is slow and may need a breaker, and water does not drain down through it. That last point matters for planters and low areas beside a slab.
My gravel driveway turns to mud or washes out. Will concrete fix it?
Yes. A decomposed granite or gravel driveway on a slope loses material in every big storm and ruts where tires turn. Concrete stops that. The runoff still has to be handled, since a paved drive sheds more water and sheds it faster. On a long rural drive, paving only the steep section or the wash crossing can solve most of the trouble for less money.
My patio was poured over an uncompacted trench and it settled. What now?
A settled strip that follows a line across the patio is the mark of a trench underneath, usually for a pool, gas, sewer or irrigation line. If the slab is intact it can be lifted and the void filled. If it has cracked along both sides of the trench, that strip is cut out, the backfill is compacted in layers and the strip is poured again with dowels into the old slab.
Should I raise a patio or slab on a flood-prone lot or near a wash?
Raising a patio alone does little, and filling in a flood area can be restricted. On a flood-prone lot, check first whether the property lies in a mapped floodplain or has a drainage easement, because Scottsdale regulates building and filling there. Never block or narrow a wash. Flat concrete that gets wet in a storm is not harmed. Design it so water crosses or passes it and leaves no mud behind.
Your own price comes from a free visit, a tape measure and a written quote. Call (480) 771-7722 or text a photo of the area.