Interior waterproofing is really water control. Water in your walls is drained and directed under the floor before it enters the room. This option is frequently called for when outside additions or structural elements are in the way, or a less expensive alternative to outside waterproofing is desired. Sometimes there is a need to remove water which is trapped below the floor that an exterior system cannot evacuate.
Water entering the basement is usually most obvious at the joint along the bottom of the basement wall or along expansion joints. Water beneath the floor can also push concrete upwards as the soil below swells, cracking the floor and then flowing into the room. Interior floor cracks and open joints can also allow radon gas to enter the home. A sump pump is almost always installed to collect the water and pump it outside. A battery backup pump is a good idea if you ever have power outages so your basement won’t flood. This method of water remediation is our second choice most of the time, but works well to keep the interior floor dry, and is a good lower cost option, especially when selling a home. Often a white plastic panel is installed over the wall to direct surface water into the floor, hide any wall damage or discoloration and dress up the walls with a maintainace free bright surface.
Once the problem has been diagnosed and the repair plan agreed upon, your work will be scheduled after permits are secured. (if required).
Normally 5′ to 6′ is generally needed to be cleared away from the walls by the customer before work can begin. Starting against the wall we remove around 18” of the concrete floor with jackhammers. This continues along the entire length of the wall to be waterproofed. We then hand excavate this trench down until we reach the bottom of the footing. The concrete and dirt is taken out to our trucks and hauled away. We then drill small drainholes in the cores at the bottom of each block to drain the wall and relieve some of the outside pressure. Drain tile is installed along the inside wall trench against the footing, a thin white plastic panel called rigid sealer is placed in the trench to cover the small drainholes and extends about 12” above the poured floor., or can be taken all the way to the top of the wall. The draintile is then buried in washed pea gravel. The entire length of pipe is sloped to direct water into a buried sump pump located at the lowest point of the system and usually in a corner. An electric connection is made from the pump to the breaker panel. A heavy duty cast iron pump then takes the collected water and automatically pumps it outside through a drain pipe which we connect to the outside downspout. Once this system is installed with the floor re-poured, the system virtually disappears and only the sump pump cover and the discharge pipe are seen.