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Concrete patios that send water away from the basement
A patio is the slab most likely to sit right against the house, and in Metro Detroit that usually means right against a basement wall. On a flat clay lot, a patio that tilts even slightly the wrong way turns every storm into a puddle beside the foundation, and every winter into a sheet of ice by the back door. The useful questions about a new patio are less about color and pattern and more about where the water goes, what the slab rests on, and how it meets the house.
Start with the basement, not the patio furniture
Most homes across the three counties have basements, and many older ones have block foundations with window wells set low along the back wall. A patio poured tight against that wall becomes part of the foundation drainage system whether anyone planned it that way or not. If it pitches toward the house, rain and snowmelt run straight to the seam between slab and wall and find their way down along the foundation.
Before any forms go up, take stock of the back of the house. Where do the downspouts empty? Is there a sump pump discharge line, and where does it daylight? Do window wells sit below the planned patio height? Has the basement ever taken on water along that wall? These answers shape the design more than the size of the table you want to fit.
A patio can often improve a wet basement situation rather than worsen it, provided it is built with a steady slope away from the house, downspouts are carried past its far edge, and window wells are protected with proper liners and covers. Ask the contractor to walk through each of those points on site.
Pitch on a level lot: small numbers, big consequences
Patios need only a gentle fall to drain, commonly around a quarter inch or so for every foot of width, which is barely noticeable when you stand on it. On a sloping yard that fall is easy to get. On the typical flat Detroit-area lot it has to be designed, because the far edge of the patio still needs somewhere lower to send the water.
That can mean setting the slab a little higher at the house, lowering the grade beyond it, or adding a shallow swale in the lawn to lead water off to the side yard. Where none of those is practical, some patios include a drain or channel that carries water to a suitable outlet. Whatever the approach, the quote should say which way the surface will slope and where the water ends up. "Standard slope" is not an answer.
Keep the height of the finished slab in mind as well. It should sit below the door sill by a comfortable step and below any siding or brick weep holes, so that splashing water and drifting snow are not pushed into the wall.
What the patio sits on in a backfilled yard
The ground within several feet of a basement is backfill: soil that was dug out for the foundation and pushed back in afterward. Unless it was compacted in thin layers, and often it was not, it keeps settling for years. Patios poured over that zone are the ones that later crack in a line parallel to the house or tip back toward it.
Good preparation removes sod and soft soil, then builds up a crushed-stone base that is compacted in lifts. Where backfill is deep or obviously soft, the contractor may dig further or recommend waiting until a new addition or foundation repair has had time to settle. Large maples and silver maples, common in older Metro Detroit neighborhoods, send shallow roots under patios and pull moisture from clay in dry spells. Mention any big trees nearby, since roots can both lift a slab and cause the clay beneath it to shrink.
Sizing a patio for how you will really use it
A patio almost always feels smaller once furniture is on it. A table with chairs pulled out, a grill with room to open its lid, and a clear path from the door to the yard all take more space than a sketch suggests. Mark the outline with a hose or stakes and string, set out the furniture you already own, and live with it for a weekend before settling on dimensions.
Think about future loads too. A hot tub filled with water weighs far more than a slab under chairs, and it needs a pad planned for that weight, with any electrical work sorted out beforehand. A fire table, a heavy masonry grill island or a pergola with footings all change what the slab or the ground around it must carry.
Joints, reinforcement and finish on a backyard slab
Patios shrink and crack like any other slab, so they need planned control joints laid out in roughly square panels, with no panel much longer than it is wide. A joint plan that follows the lines of the house and the door openings tends to look deliberate rather than random. An isolation joint where the patio meets the foundation lets the two move independently.
Fibers, welded wire or rebar can be used to keep any cracks tight, and as with any slab, steel only helps when it is supported inside the concrete during the pour. Ask which option is planned and why.
For the finish, a light broom texture gives the most grip on wet or frosty mornings. Smooth trowel finishes look sleek but turn slick. Exposed aggregate, stamped patterns and integral color are all options that change the look and the upkeep. The stamped and decorative page covers those choices in more depth.
Questions a patio quote should answer in writing
- Which direction the patio will pitch, how much fall is planned, and where the water will end up.
- How downspouts, sump discharge lines and window wells along that wall will be handled.
- How deep the excavation will go and how thick the compacted stone base will be.
- Slab thickness, including any area planned for a hot tub or heavy grill island.
- The control joint layout and whether an isolation joint will separate the slab from the house.
- The finish, the curing method, and when sealing is recommended.
- Whether removal of old pavers, concrete or sod and cleanup of the lawn edges are included.
Living with a new patio through the first year
Fresh concrete keeps gaining strength for weeks. Keep heavy planters and the grill off it until the contractor says it is ready, and do not drag furniture across it while it is young. In the first winter, skip chloride de-icers on the patio entirely; shovel it and use sand if you need grip. Watch where water goes in the first few big storms and let the contractor know promptly if it collects anywhere near the house.
Concrete patios that send water away from the basement — common questions
Will a new patio make my wet basement worse?
It should not, and it can help, provided the patio pitches away from the house and downspouts discharge beyond its outer edge. Problems come from slabs that tilt toward the foundation, from open seams where the patio meets the wall, and from window wells left lower than the new surface. Point out any past basement leaks during the visit so the contractor can plan grades and drainage around that wall.
Should the patio be attached to the house foundation?
In most cases the patio is poured next to the foundation but not tied into it, with an isolation joint between them so each can move on its own. Frost and settling affect a slab and a basement wall very differently. A flexible sealant in that joint keeps water from running down the wall. Porches and additions with their own footings are a different design question for the contractor.
What footprint does a dining set actually need on a patio?
More than most people guess, and your own furniture sets the real number. Allow room to pull every chair back and walk behind it, plus a clear path from the door to the steps or lawn. A grill needs space on all sides and should sit away from siding. The easiest test is to mark the outline with stakes and string, place your furniture inside it, and adjust before committing to a size.
Can a patio be poured over my old cracked slab or pavers?
Pouring over an old slab or pavers is sometimes proposed but is usually a poor bet here. The new concrete inherits every crack, settled area and drainage flaw of what is underneath, and it raises the surface closer to door sills and siding. Removing the old material and building a proper base is more work, yet it is the approach that gives the new patio a real chance to last.
What finish is least slippery on a patio in winter?
A broom finish offers the most traction on wet or frosty concrete, which is why it is the default for many backyard patios near doors. Exposed aggregate also gives good grip. Smooth troweled and some stamped surfaces can be slick, especially after sealing, so ask whether a grit additive can go into the sealer. Keeping the patio shoveled rather than packed with ice matters as much as the finish.
Can I put a hot tub on a regular concrete patio?
A filled hot tub is a heavy, concentrated load, so the section under it usually needs to be planned for that weight, with a well-compacted base and often a thicker slab. Check the tub maker's requirements, and arrange any electrical work before the pour so conduit can be placed. Tell the contractor about the tub during the first visit, even if you plan to buy it later.
Talk through your project
Start with the address, what you want poured or replaced, rough dimensions, and a few photos of the area and any existing concrete.
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