Your roof collects a small lake. Where it lands is up to you.

What to know about downspout extensions, and when it's the right call.

A downspout extension works by moving the discharge point of your roof drainage past the zone where water can reach the foundation. Roof runoff enters the gutter, drops down the existing downspout, and instead of splashing out at the foundation line, continues through connected solid pipe. The pipe runs with a continuous downhill slope, above ground where that is unobtrusive or buried a few inches below the lawn where it is not, and releases the water at a planned discharge point well away from the home. From there the water disperses into soil that can absorb it harmlessly or joins a surface drain system headed for the street or a swale. The soil beside your foundation goes back to receiving only the rain that falls on it directly, which is a load it can usually handle on its own. Extensions do their best work as part of the outside first sequence: intercept ground flow with strategically placed yard drains, move roof discharge past the foundation zone, and only then size any interior measures to what still arrives. If your symptoms match our seasonal groundwater seepage description, correcting the roof water that recharges the soil beside the house is often the difference between a wet season and a dry one.

The symptoms that usually lead to downspout extensions are on the crawl space repair problem signs page, alongside the other signs that point to the same underlying cause.