Basement Waterproofing Basics: Positioning Your Downspouts
Your home’s rain gutters are one of its most important defenses against damage from stormwater runoff. Keeping them clean should be one of the most important chores on your list; you should clean them out about once a month so they don’t spill water over the sides and risk damaging your foundation. But all the cleaning in the world won’t matter if your downspouts aren’t properly positioned.
When you install new gutters, you should think of it as a basement waterproofing measure. If water pools too close to your home’s foundation, it can leak into your basement and cause problems. So it’s important to keep your downspouts the proper distance from the house.
Make sure your downspouts are the right size. Except for small roofs or canopies, roughly seven square inches should be the minimum. Otherwise your gutters will back up and overflow.
Make sure your downspouts are connected properly. For that matter, make sure all the joints in your rain gutters are sealed properly. Leaky joints make for water pooling around the foundation.
Check your downspouts for rust. Rust can create holes, and holes can lead to pooling water.
Have the proper number of downspouts. A good rule of thumb is one downspout for every 40 feet of gutters.
Include splash blocks. A splash block is a length of concrete that carries water away from your foundation to avoid pooling. Every downspout should drain onto its own splash block.
Try berms and swales. A system of raised ridges and shallow ditches can carry water far away from your foundation into its own retention pool, where it can slowly evaporate (or provide a small, well-designed wetland that makes your property more attractive).