Basement waterproofing is critical to protecting a building’s foundation from water damage. Hydrostatic pressure is one of the key factors to consider when designing an effective waterproofing system. This blog will delve into hydrostatic pressure, its impact on basements, and how it can be managed through proper waterproofing techniques.
What is hydrostatic pressure in waterproofing?
The pressure that a still body of water exerts on the water column above it as a result of gravitational attraction is known as hydrostatic pressure. Hydrostatic pressure, related to basement waterproofing, is the force groundwater applies to the foundation walls and floor. The structural integrity of the basement is significantly put at risk due to this pressure growing as the depth of the water table rises.
Can hydrostatic pressure push water into the basement?
The basement floor and walls experience hydrostatic pressure when the water table around a building’s foundation rises. Let’s say the basement walls have fissures, openings, or porous regions. In that situation, the pressure may drive water through these apertures and into the basement. Water seepage or water infiltration are two terms used to describe these phenomena. As hydrostatic pressure rises, it can result in major water damage, moisture, mould growth, and structural damage to the basement, among other problems. Hydrostatic pressure can be managed and prevented using effective basement waterproofing methods.
The Clay Bowl Effect
The Clay Bowl Effect is a phenomenon that happens, especially in locations with clay-rich soil, when hydrostatic pressure pulls water into basements or below-ground constructions. Let’s dissect this effect step-by-step to better comprehend it:
1. The characteristics of clay soil are that it is made up of very small, fine-grained particles. Water can be retained in it, and its low permeability makes it difficult to drain.
2. Rainfall or Water Accumulation: When it rains or water is abundant, the ground becomes saturated with water. In locations with clay-rich soil, the clay absorbs and holds onto rainwater inside its structure.
3. Water Absorption: When clay absorbs water, it expands. This expansion increases the volume of the clay soil.
4. Hydrostatic Pressure: The expanding clay soil creates hydrostatic pressure, or the force that the water within the soil exerts against its borders. The depth and volume of water are directly related to the pressure.
5. Path of Least Resistance: Water naturally takes the route of least resistance, which in this case is through the basement walls or floors’ fractures, openings, or porous materials. Water is forced into these weak spots by the hydrostatic pressure.
6. Basement Leakage: Water can permeate and enter the basement, producing leaks or flooding when the hydrostatic pressure exceeds the structural integrity of the basement walls or floors.
Effects of Hydrostatic Pressure on Basements:
If not correctly handled, high hydrostatic pressure can cause a number of problems in the basement. These consist of:
- Excessive hydrostatic pressure in the basement’s walls and floor can push water through holes, fissures, or porous materials, causing seepage and leaking.
- The foundation walls may become more vulnerable to hydrostatic pressure over time, which may result in structural failure, bowing, or cracking.
- Hydrostatic pressure-induced moisture seepage provides a wet atmosphere that encourages the growth of mould and mildew, which can degrade indoor air quality and present health risks.
How do you fix hydrostatic pressure in the basement?
Effective basement waterproofing techniques should be used to lessen hydrostatic pressure’s impacts. Here are some essential methods:
1. Exterior Waterproofing: In this technique, the area next to the foundation walls is dug up and a waterproof barrier, like a membrane or coating, is applied. This helps deflect water away from the foundation and offers a barrier of protection against water infiltration.
2. Interior Waterproofing: Basement water seepage is controlled using interior waterproofing techniques. Installing drainage systems, including inside French drains, sump pumps, and waterproofing coatings on the interior walls, may be necessary to achieve this.
3. Crack repair: Water can easily enter the foundation through cracks in the walls or floor. Using epoxy injection or polyurethane foam to properly seal these gaps can help to reduce hydrostatic pressure and stop water seepage.
4. Drainage Systems: Setting up an effective drainage system both inside and outside the basement aids in gathering and rerouting water away from the foundation. This includes outside grading, gutters, and downspouts that are correctly designed and built.
5. Injection of Sealants: To help stop water seepage, specialised sealants like epoxy or polyurethane can be injected into crevices and cracks in the foundation walls. These sealants build a barrier against water infiltration by successfully filling the gaps.