Plan around how you'll use the space
A patio should fit how you'll use it: dining, lounging, a grill area, a hot tub. Measure furniture and leave room to walk around it. Consider sun and shade at the times of day you'll use it, and where steps from the house will land. Walkways should be wide enough for comfortable walking and for moving things like wheelbarrows and bins.
Drainage comes first
Patios and walkways next to the house must slope away from the foundation so rain and melting snow don't run toward the house. A gentle slope that's barely noticeable when walking does the job. Walkways should not create dams that trap water against the house or in planting beds. Ask the contractor how they'll slope the slab and where the water will go.
Base and thickness
Like driveways, patios and walkways need a firm, compacted subgrade and a compacted aggregate base. Patios that will carry a hot tub, an outdoor kitchen or heavy masonry features need extra thickness and reinforcement in those areas. Tell the contractor what will sit on the slab before they design it.
Steps and transitions
Concrete steps need consistent rise and run heights; uneven steps are a tripping hazard. Codes may require handrails on steps above a certain height. Where a patio meets the house, an isolation joint separates them, and the patio should sit below door thresholds and siding by enough to keep water out.
Finishes
- Broom finish gives traction and is the most common.
- Exposed aggregate reveals the stones in the mix for a textured, slip-resistant surface.
- Stamped and colored concrete imitates stone, brick or tile.
- Smooth or troweled finishes look sleek but can be slippery when wet.
Choose finishes with traction in mind for areas that get wet.
Joints and cracks
Control joints placed at the right spacing give cracks a planned place to form. Decorative saw cuts can double as control joints and create a tile-like pattern.
Sealing
Sealing helps protect concrete from stains and moisture, and is especially helpful for colored and stamped concrete and in climates with freeze-thaw cycles. Ask which sealer the contractor recommends and how often to reapply.
Around trees and utilities
Tree roots can lift slabs. Avoid cutting major roots, which can harm or destabilize trees. Call 811 before excavation to locate buried utilities, and point out private lines such as irrigation and landscape lighting.
Questions to ask
- How will you slope the patio and walkways for drainage?
- How thick will the slab be, and will areas under heavy features be reinforced?
- What finish do you recommend for traction?
- Where will the joints be?
- Will you seal the concrete, and how often should it be resealed?
- Will you call in a utility locate before digging?
Patio size and layout
A patio that's too small is the most common regret. Lay out the space with a garden hose or stakes and string, and set your furniture on it before the concrete is ordered. Leave room to walk around a table with chairs pulled out, and think about where a grill can sit safely away from the house and overhangs.
Connecting to other surfaces
Where a new patio meets an existing slab, steps, a deck or the house, isolation joints let each part move independently. Matching the color of new concrete to old is difficult; a deliberate border or a decorative finish can make the transition look intentional.
Repairing an existing patio
Small cracks can be sealed. A patio that has settled toward the house is a drainage problem and may need lifting or replacement. Surfaces that are flaking or scaling can sometimes be resurfaced if the slab underneath is sound.