Roof Water and Downspout Planner
Free foundation tool

Roof Water and Downspout Planner

Enter your roof size and downspouts to see how much water lands at your foundation in a heavy rain.

These tools give planning-level estimates from typical values. They are not quotes, designs or engineering, and results depend on your actual foundation, soil, drainage, site conditions and local rules. Only a site visit can confirm what a project needs, and we give you a written scope and price before any work begins.

How it works

Four quick steps.

  1. 01

    Enter the roof area

    Footprint in square feet, a rough size is fine.

  2. 02

    Set the downspouts

    How many carry the roof water down.

  3. 03

    Pick the storm

    A steady rain, a heavy storm or a downpour.

  4. 04

    Read the result

    How much water lands at the foundation and how far to move it.

Tips

  • A single heavy storm can drop hundreds of gallons beside a foundation through one downspout.
  • Extensions or buried pipe that discharge well away from the wall are one of the most helpful, lowest-cost fixes.
  • Check gutters for clogs and slope each season.
Questions

About this tool.

Is this exact?

No. It is a planning estimate from roof area and rainfall. Roof pitch, gutters and the way water is routed change real results.

How far should downspouts discharge?

As far as practical from the wall, and beyond the loosened soil next to the foundation.

What about buried pipe?

It carries water farther and out of sight, to daylight or a drain.

Free estimate

Ready for a foundation you can count on?

Call us and we will visit, look closely at your foundation, crawl space or slab and give you a clear plan and a written scope.

Call NowFree Estimate