Whether your retaining wall is bowing, cracking, crumbling or just doesn't look right, evaluating the issue is a job for a professional. Unless you have expertise in engineering or constructing these exterior walls, incorrectly assessing the situation may cost you time and money right now or down the road.
Even though it's not advisable for a homeowner to repair or replace their own retaining wall, that doesn't mean you should go without understanding what can threaten it. Educating yourself on some of the common problems that these walls face can help you to better communicate with the contractor and make an informed decision about your exterior issues.
What are some of the most common issues that can literally take down your retaining wall? Take a look at the possible culprits behind the crumble.
Nonfunctional Weep Holes
Rainstorms and serious snow melt can cause water to seep deep into the soil. The more moisture in the soil, the more lateral force is exerted on your retaining wall. This increases the hydrostatic pressure and can result in retaining wall failure. In other words, when water is stuck in the soil behind the wall, it can push the stone or other building material outward.
Weep holes are added to retaining walls as a drainage method. These holes provide an escape route for excess water, alleviating the pressure behind the wall and allowing it to keep its shape. But if there are no weep holes, or the weep holes are clogged/nonfunctional, the water has nowhere to go.
When building a new wall, the professional contractor should take hydrostatic pressure into consideration and add weep holes in your wall. If you have an existing wall without working weep holes, the contractor can investigate the cause of the clog and make repairs or plan a way to create additional drainage and install new holes.
Your wall's backfill sits directly behind the stone, brick or other building material. The correct type of backfill allows for drainage, relieving some of the hydrostatic pressure. Incorrect backfill has the opposite effect and may increase the pressure that water-soaked soil puts on your wall. Again, as with nonfunctional weep holes, this can cause your wall to fail.
Crushed gravel is an acceptable material that won't increase the pressure exerted on the wall. A material that easily soaks up water, such as soil with a heavy clay component, can easily swell and add to the pressure that your wall is trying to retain.
A retaining wall is engineered to hold a specific load. Dramatically increasing that load can put pressure on the wall that it just can't contain.
While an extra layer of mulch, a few plants or your dog taking a nap on the backyard's soil won't cause an issue, installing an above-ground pool or building a shed (or a similar type of construction) can.
Without a barrier, nearby tree roots can grow and press against a retaining wall. If this has happened to your wall, you may notice a few blocks or bricks pushing outward near the root line. This bowing will persist until it damages the integrity of the wall.
In an ideal world, your tree roots wouldn't grow toward the edge of your exterior walls. Instead, you may have to take preventive measures. This may mean removing the tree before it topples your wall (and your yard too). Or it may mean that you need to install root barriers. A professionally installed root barrier will do exactly what the name says - provide your wall with a barrier from spreading roots.
Do you need a new retaining wall? An expertly installed wall can help to reduce the risks of cracking or bowing. If you're ready to reconstruct your home's exterior, contact Supreme Concrete LLC for more information.