Exterior drain tile systems, also known as footing drains, are usually installed during initial construction of the home. Most are also combined with some type of membrane that is applied to the exterior of the foundation walls that protects them and helps the water reach the drain tile. The drain tile acts as a collection system for subsurface water that moves down the foundation walls through the soil, it then brings the water to an interior sump pit where the sump pump turns on and pumps the water away from the home. Despite its high cost, installing an exterior drain tile system on an existing building is the most effective way to control water and protect the foundation. This process involves excavating the area around the foundation, waterproofing it, installing pipes, back filling with gravel, and then replacing the majority of the soil.
When Reliable Basement Services is installing an exterior drain tile system, we first remove shrubs and other obstacles around your house. This may involve removing sidewalks, concrete stoops, decks and other structures attached to the home. We must drain the exterior drainage system to a sump pit that can be pumped out.
It isn’t always practical to waterproof a basement from the inside if you already have a finished basement, especially if you have expensive finishes and built-in amenities. That makes an exterior drain tile system your best option. We start the process by excavating a trench next to the foundation wall all the way down to the footing. Next, we apply a liquid coating directly to the foundation and then install a rubberized waterproof membrane that adheres to the liquid coating, then we cover it all with a dimple sheet that allows water to make it to the drain tile. We install PVC drain tile that will drain into a sump pump pit (pictured below). We backfill with 12 inches of washed gravel. By using a filter sock around the pipe, we prevent dirt from clogging the exterior drain tile and then backfilling with existing soil.
If it’s necessary, we can remove concrete or asphalt driveways, walkways, or patios. In most installations, we excavate by hand to reduce damage to your landscape. We always leave an acceptable grade tapering the soil away from the foundation.