Avoid moving patio water toward the house

Record existing conditions before design

From safe locations, note where water collects after rain and how runoff moves around the house. Photograph low spots, stained walls and troublesome downspout areas. Provide any available survey and previous drainage information to the designer.

Ask for measured levels rather than relying on an impression that the patio looks flat. Identify doors, wall interfaces, adjoining paths and relevant property boundaries. If the project changes substantial grading or runoff, ask which qualified professional should assess it.

Review the house interface explicitly

Ask the team to explain how the proposed paving level and exterior-water strategy relate to the door threshold and wall assembly. Request a detail for the connection rather than treating it as a finish decision.

EPA’s moisture-control guidance identifies site drainage as part of protecting buildings from water. Use that principle to ask how water is managed before it reaches the house, including runoff from an existing or new patio roof.

Trace the full runoff route

Ask where water leaving the patio will go, how it reaches that destination and who is responsible for the receiving area. A drain symbol on a plan is incomplete without a coordinated route and suitable destination.

Have the project team check applicable local drainage, grading and discharge requirements. Consider neighboring property and public areas; do not assume sending water away from your doorway settles the entire issue.

• Existing and proposed elevations at critical interfaces.
• Roof and downspout runoff entering the patio area.
• Normal drainage route and maintenance access.
• Potential consequences if an inlet becomes obstructed.
• Interaction with landscaping, irrigation and future pool work.
• Local review or approval responsibilities.

Coordinate the finish with the approved plan

Choose paving thickness, surface treatment and joint details with the designer after the elevation strategy is understood. Ask how changes in material affect thresholds and adjoining surfaces.

Before handover, request the drainage layout and maintenance instructions, along with a walkthrough of accessible components. Report unexpected ponding or water entry promptly for professional review. This is a planning checklist, not a prescription for slopes, drain sizes or discharge methods; those decisions require the actual site conditions.