Underground sprinklers near foundation walls cause problems
If you live in the Northern hemisphere, it is summer, and the living is easy. Fish are jumpin, you know the rest of the song! As happy homeowners we water our lawns and bask in the sun in our backyards. Lemonade and puffy clouds are on our minds. Birds chirp, and butterflies flitter. We forget about home drainage problems, and those nasty winter rains out of a need for a rest from the tiring thoughts of eventually having to deal with those home drainage issues before the rains and snow comes.
Take in this food for thought concerning your sprinkler systems. Most in-ground sprinkler systems are designed and installed by contractors that do not consider the homes’ need for foundation drainage. Many of these installers place sprinkler pop-up heads inches from the foundation wall. In addition, landscapers cover the sprinkler heads with barkdust or dirt, making them a soggy below grade drainage problem.The logic from the sprinkler installers’ point of view is sound. The sprinkler pop-up heads direct the sprayed water away from the foundation wall, and are designed to be directional, spraying away from the foundation. It’s o.k. what’s the problem Mr. Drainage Guy? In practice however, the sprinkler heads, many times, water only barkdust areas or dirt next to the foundation that soaks up water.
If sprinklers do water planted areas, many of these planted areas contain trees and shrubs that have roots making pathways along the foundation, and those roots provide pathways for rain and sprinkler water to run right down the roots to the foundation wall.
Sprinkler heads are likely to bleed out water after they are shut off as well. The water draining out of the sprinkler heads, especially sprinkler heads at the low end of the system, will keep those areas wet nearly all the time. When winter rains come, and the need to water goes away, the wet areas become areas prone to saturation and hydrostatic pressure during the rains or snow.
As a result, groundwater entry into crawlspaces and basements is greatly increased.
I love to see areas of flowers and plants adorning the areas near the foundation. I admit, they look great. It is great curb appeal. The caveat however is that there is a price to pay in terms of a dry foundation wall. Plants like bamboo are really bad for the foundation area. Large trees and other heavy rooting plants can lift, crack and destroy your foundation.Cap the sprinkler heads that are very near or on the foundation wall and water the plants in that area with the hose. This will produce a drier crawlspace or basement. I like to see homeowners install hand excavated french drain groundwater removal systems approximately 18″-24″ from the foundation wall, and create a compacted splash block of soil or clay from the foundation wall to the inside of the french drain.
Your landscapers are not to excavate into the sides of your french drains while planting. Counsel your landscapers to not dig into the sides of your hand excavated french drains. Make it a point that they understand and acknowledge this . This practice can cause the hand excavated french drains to silt in places, and work less effectively over time.Finish the top of your hand excavated french drain with exposed rock on the top layer for maximum groundwater collection. Groundwater caused by your irrigation system still becomes groundwater just like rain when over watered areas saturate and cause hydrostatic pressure against the exterior foundation walls.
Subordinate some of the need to have foundation plantings to your home drainage requirements for a healthy home and more monetary and structural value in your home as a result of proper management of sprinkler systems near your foundation.
We call the planted areas on our foundation curb appeal, but many times these landscape beauties can be part of a destructive process for your foundation, crawlspace and basement if not put in place with the priority on placement and maximum groundwater collection and movement around the foundation of the home.