Home › Services
Concrete patios: pitch, shade and the house wall
A patio looks like the simplest concrete there is: a flat pad behind the house. In practice it is the slab most likely to send water the wrong way, because it sits right against the foundation on a back yard that often tilts toward the house. Around Birmingham, where summer storms drop a lot of rain in a short time and back yards frequently step down a hillside, the layout and pitch of a patio matter more than its pattern. This page explains how to judge those choices before anything is formed.
Start with where the rain goes today
Before talking about size or finish, stand in the back yard during or just after a heavy afternoon storm. Notice where the downspouts empty, where water sheets across the grass, and where puddles linger the next morning. A patio is a large hard surface that will collect all the rain landing on it and send it somewhere. If the yard already drains toward the back door, a slab poured in that spot will make the problem worse unless it is designed to move water away.
Share what you see with the contractor. Photos of standing water, a soggy crawlspace vent or mud splashed on the siding are more useful than a sketch of the patio you want. They show what the concrete has to fix as well as what it has to hold.
Pitch: the small tilt that keeps the foundation dry
A good patio is never perfectly level. It is pitched gently away from the house so water drains off the far edge, usually by a small amount per foot that is barely noticeable when you set a chair on it. Too little pitch and water ponds near the back door. Too much and furniture rocks and a spilled drink races toward the yard.
Ask the contractor which direction the patio will fall, how much, and where the water will go after it leaves the slab. On a lot that drops downhill behind the house, the answer is simple. On a flat or reverse-sloped yard, the plan may involve a shallow swale, a drain along one edge, or moving a downspout. Those items belong in the estimate, not in a conversation after the pour.
The joint against the house
Where a patio meets the foundation, the two should not be locked together. An isolation joint, a strip of compressible material set along the wall before the pour, lets the slab and the house move independently as the clay under the yard swells and shrinks. Without it, the patio can crack along the wall or pull the siding trim with it.
Check the height too. The finished surface should sit low enough below any door threshold that wind-driven rain does not blow inside, and it should never bury siding, weep holes or the bottom row of brick. On older homes in neighborhoods like Crestwood or Homewood, where back doors sometimes sit close to grade, this can shape the whole design.
What a Birmingham back yard does to the base
Back yards are often where builders left the loosest fill: soil from the foundation dig, old construction debris, or material pushed in to level a slope. Add the red clay common across the area and you have ground that can settle in some places and swell in others. A patio over that mix needs the soft material removed and a compacted layer of crushed stone laid in its place.
Tree roots are the other common issue. Mature oaks, pines and sweetgums shade many yards in the area, and their roots both lift slabs and dry out the clay beneath them during long summer dry spells. The contractor may suggest shifting the patio a few feet, cutting certain roots, or accepting some risk near a large trunk. Ask what they recommend and why.
Heat, glare and choosing a surface you can walk on barefoot
Plain gray concrete in full afternoon sun gets hot and bright during a Central Alabama summer. Lighter integral colors and textured finishes reduce glare, and a broom or light exposed-aggregate finish stays less slippery than a smooth trowel finish when it rains. If the patio faces west with no shade, consider how it will be used at six in the evening in July before settling on the finish.
Humidity plays a role as well. Shaded patios can grow mildew and algae on the surface, especially near downspouts and under trees. Proper pitch helps the slab dry out between storms, and a breathable sealer can make cleaning easier. Ask the contractor how the finish you prefer tends to age in a damp, shaded corner.
Size, thickness and things that will sit on the patio
- Furniture and a grill: a typical four-inch slab on a good base is usually plenty.
- A hot tub: the filled weight is concentrated, so mention it early; the contractor may thicken or reinforce that section.
- A future roof or pergola: posts need footings, which are easier to plan now than to cut in later.
- An outdoor kitchen or fire feature: plan gas lines, electrical conduit and drains before the pour.
- Steps down to the yard: the grade change often decides the patio height, so design both together.
Control joints that match the patio shape
Joints on a patio are not only about crack control; they also shape how the slab looks. A square patio can be divided into even panels. An L-shaped patio needs a joint at the inside corner, where cracks almost always start if one is missing. Curved edges need joints that run perpendicular to the curve rather than straight across it.
Ask to see the joint layout on paper before the pour. A contractor who draws it out has thought about where the slab will want to crack and has given it a neat line to follow.
Reading a patio estimate side by side
When two patio quotes arrive, set them next to each other and look for the same handful of items: the finished size and shape, the slab depth, what will be dug out and what stone goes back in, the direction and amount of pitch, the isolation joint at the house, the joint layout, the finish, and any drainage work such as a swale or relocated downspout. A low number with half of those missing is not a bargain; it is a smaller job.
Also ask how the concrete will reach the back yard. Many lots around the metro have a fence, a retaining wall or a narrow side yard between the street and the patio site, which can mean a pump truck, a line of wheelbarrows, or temporary removal of a fence panel. That access plan belongs in writing so nobody is surprised on pour day.
Curing and the first season
Keep the new patio clear of furniture, grills and planters until the contractor says it has cured enough. In summer, curing protection matters because the sun and warm breezes can dry the top surface quickly. Avoid pressure-washing or applying sealer until the timing the contractor recommends has passed. A hairline crack along a joint in the first season is normal; one that runs across a panel and widens is worth reporting.
Concrete patios — common questions
How big should a patio be for a table and chairs?
Measure the table with the chairs pulled out, then add walking room around it and space to reach the door without squeezing past anyone. Many homeowners find that the patio they first sketch is too small once a grill and a couple of lounge chairs are added. Lay out a garden hose or string in the yard for a week to test the size before the contractor forms it.
Can a new patio be attached to my existing one?
Yes, an extension is common, but the two slabs should be separated by a joint rather than locked solidly together, because the old and new concrete will move differently. The new section should also match the drainage direction of the old one. Color and texture rarely match perfectly, so some homeowners choose a contrasting border or finish to make the difference look deliberate.
Why does water pool on my patio after it rains?
Pooling usually means the slab was poured too flat, has settled toward the house, or has a low spot where the base was not compacted evenly. On older patios, a corner can also drop as soil washes out beneath it. A contractor can check whether the slab can be lifted back to a proper pitch or whether the section needs to be removed and rebuilt.
Is a concrete patio better than pavers here?
Each has trade-offs. Poured concrete forms one continuous surface with fewer places for weeds and ants, and it is simple to sweep. A paver patio forgives some ground movement, since a sunken spot can be lifted out and rebedded, though their joints need upkeep. On clay soil either one depends on a well-compacted base. The contractor can walk you through how each would handle your yard and the way you plan to use it.
Will a patio next to the house cause foundation problems?
A well-built patio usually helps, because it sheds water away from the foundation instead of letting it soak in. Problems arise when the slab tilts toward the house, when it covers weep holes or siding, or when it has no isolation joint along the wall. Ask the contractor to show how the patio will slope and how it will meet the house before approving the plan.
What can I do about a patio that gets too hot in summer?
Lighter colors and textured finishes reflect more sunlight and feel cooler than dark or smooth concrete. Shade makes the biggest difference, whether from a tree, a shade sail or a pergola with footings planned before the pour. Some decorative coatings also reduce surface heat. Ask the contractor for samples, and look at them in direct afternoon sun rather than indoors or under a cloudy sky.
Do I need approval to build a backyard patio?
Sometimes. Some cities and counties require review for new hard surfaces, particularly near property lines, easements or drainage paths, and many HOAs ask to approve exterior projects in advance. Because the rules vary from one place to the next, check with your city or county office and your HOA before the contractor schedules the work, and keep a copy of any approval you receive.
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.
Related work
Concrete Driveways
New drives, widening and tear-out on sloped Birmingham lots.
Stamped & Decorative Concrete
Pattern, color and aggregate finishes, and the sealer they need.
Walkways & Steps
Front walks, stoops and even steps up hillside yards.
Garage, Shed & RV Slabs
Pads for sheds, shops, garages, boats and campers.
Concrete Repair & Replacement
Reading a failed slab before choosing patch, lift or tear-out.