Gutters, Downspouts, and Drains

Among the most common reasons for moist basements and crawl spaces is an inadequate gutter, downspout, and drain system. Gutters are required at all locations where water drains off the roof. Gutters and drains need to be adequate in size and quantity to handle all but the heaviest of torrential downpours. The purpose of the entire system is to divert the water collected on the roof away from the house and its foundation. The diverted water may be drained into a storm sewer or an on-side "french drain" or similar system. We recommend that homeowners review the adequacy of their gutter, downspout, and drain system on an annual basis. This can be done during a heavy rain, at which time all of the water from the roof should disappear into the gutters and flow through the downspouts and the drains, without spilling over onto the ground next to the house.

Index

  • This was the traditional construction system employed and is rarely used today. The original wood gutters were made from old growth cedar, a product which is rarely available today. Its substitution with new growth cedar or hemlock gutters has proven inadequate. Galvanized downspouts do not tend to last as long the newer products available on the market.

  • This is a commonly used material and often sold in do-it-yourself hardware stores. It is easily installed by the homeowner, and when properly installed is a good product. It is also susceptible to damage by heavy ladders, as well as long-term deterioration by ultraviolet light from the sun.

  • This is a commonly used material and often sold in do-it-yourself hardware stores. It is easily installed by the homeowner, and when properly installed is a good product. It is also susceptible to damage by heavy ladders, as well as long-term deterioration by ultraviolet light from the sun.

  • A popular gutter style in the 1960's was the integral gutter. This system is formed by the end of the rafters and fascia in a sloped roof. The gutter is lined with a built-up roofing material and has the advantage of being able to hold a great deal more water than most of the other types of gutters. The disadvantage of this gutter style is in the potential for leaks, which can result in damage to the framing, fascia, soffit, and sheathing of the roof. In order to prevent such damage, these gutters need to be carefully inspected every few years and the lining replaced or repaired every five to ten years. Should such a gutter system prove troublesome, it is possible to convert this gutter into a standard gutter configuration at the time of re roofing.

  • Here is a splash block that doesn't work and can't be made to work.

    Even if is stays balanced on top of the bricks, the roof drainage from this splash block will drain toward the foundation of the house.

    This is a good location for a simple drain system. The basic idea here is to get the roof drainage water away from the foundation of the house.

    These concrete or plastic blocks are intended to divert the water coming out of the downspout next to the house away from the house. They are simple and inexpensive to install and rarely work. They need to be installed in an area with proper drainage and require ongoing maintenance for maximum effectiveness. I often find splash blocks draining water toward the house (see picture above) or filled with soil and grass, rendering them useless.

  • A french drain is a pit or trench located away from the house, filled with gravel or crushed rock. The water is carried to the french drain in a plastic drain tile and is absorbed into the ground. The french drain must be built far enough from the house to prevent any of the water from re-entering the basement or crawl space.

  • Where storm sewers exist, water from the gutters, downspouts, and drain systems should be diverted to this storm water system.

  • It is important to check with the local engineering department or storm water utility to ascertain the rules and regulations regarding storm water systems in your area. If a storm water system exists in your area, they are likely to have a map showing where the lines run and approximately how deep they are. Many jurisdictions require on-site systems for storm water dispersal.

  • You are not alone with your gutter, downspout, and drainage concerns. See The Sound Home Consultant for other homeowners questions and George's answers in Q&A: Drainage. See also: Topics: Downspout Drain Systems, Topics: Basement and Crawl Space Moisture, Topics: Consumer News.

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    • To reduce the likelihood of damage and the amount of leaves and other debris which clog the gutters and downspouts, be sure that tree limbs and other vegetation are kept away from the roofs, gutters, and downspouts. But when you do prune your trees, make sure that you don't damage the trees and aggravate the problem. To find out how to prune trees, take a look at The National Arbor Day Foundation site.
    • An additional way to reduce the moisture in basements and crawl spaces is to ensure a good slope away from the house for all soil, patios, and walkways. It is also important to maintain a separation of a minimum of four to six inches between the top of the soil around the house and the lowest row of siding. This prevents the li