Leaks in the basement is one of the most undesirable and most prone to housing problems. It is also one of the most concerns of buyers and homeowners. Though basement leaks can often be prevented with some proactive maintenance and knowledge of what to look-out for, many times small issues get ignored leading to major issues. I made a summary of the causes and disposal methods of basement water leaks. Due to the large amount of content, I will talk about it in three articles, first to talk about the reasons for the leaks in the basement, and then to deal with the suggestions.
1. Water leaks from the top of the foundation wall
If the grading of the external terrain around the house is not good, it is easy to accumulate water around the house, and rainwater may enter into the interior from the top of the foundation wall. This kind of problem is especially likely to happen in older houses. The soil around many old houses is dense due to age, which leads to low depressions near the foundation. Especially when the downspout and leader extension are not long enough(6 feet from foundation) and the rainwater is directly discharged to the root of the wall, this kind of problem is more likely to occur.
According to Ontario Building Act the top of the foundation must be at least 6-8 inches above the ground, depending on the material of the exterior wall panel, to protect the exterior wall panel and the wooden structure of the house from rain damage.
2.Water leaks from the basement window wells
Window wells are protective components built around exterior basement windows below ground level, and are generally protected by galvanized steel plates. Window wells can protect low windows and reduce surface water erosion. There is a drain pipe pre-buried in the window well when building the house, which leads to the drain pipe near the foundation. The upper part of the window well is cushioned with sand and gravel with good drainage performance. However, if too much sand and gravel is buried, the windowsills will be too low, and the water in the window wells, especially the large amount of water generated when the snow and ice melt in spring or it is rains heavily in summer, will enter into the room through the windows.
Sometimes homeowner wants to reconstruct the old house, the basement windows that were originally higher than the ground were enlarged downwards to be lower than the ground. At this time, a window well needs to be added to prevent rainwater enter into the house. However, in many cases, only a circle of guardrails is added without buried drain. It is predictable that during heavy rain, the surface water will be collected in the window well and flood into the room.
3.Water leaks from mortar joints
The foundation of many old houses is not cast with reinforced concrete, but is made of stones, hollow concrete blocks, etc. Mortar as a mixture will form countless joints. The strength of these joints is generally much lower than that of the wall material itself. With the passage of time and the erosion and weathering of water, these joints may break down. Due to the special structure of this foundation material, the leak point of the mortar joint is not easy to determine. For example, water leak has occurred at one point of the concrete block foundation. The actual leak point may not be here, but somewhere above. Water passed through the interior of the hollow block and flowed to a place at the bottom.
4.Water leaks from cracks of poured concrete foundation surface walls
This is always the most possible reason that we can think of. Indeed, the leaking of the foundation surface walls is the culprit of the leaking of the basement.
Firstly we need to understand what is the water table. There is natural water under the land where we live, just like a river flowing underground. In areas near lakes and rivers the water table is very high; In desert areas the water table is very low. In addition, the type of soil also has a great influence on the level of the water table. In areas where the soil is basically clay, the poor water absorption of clay may also cause the water table to be high.
When it rains, the water in the soil will gradually saturate and excess rainwater will seep into the ground, which will cause the water table to rise. This produces what is known as hydrostatic pressure. The foundation of the house will be subjected to great pressure in every direction, and water will enter through cracks in the wall, causing water leaks.
5. Water leaks from Tie Rod Holes
If you are a homeowner with an older basement, you might notice a quarter-size stain on your basement wall with a leak mark that goes down to your floor. These are known as Tie Rod Hole leaks. These little annoying, pesky holes result from the construction of your home. With older constructions, concrete forms are built from wood and held together with steel rods every 1-1/2 feet. The steel rods are typically placed in two rows being about 1 foot high from the top of your basement floor to five feet high. After removal of the rods and wood forms, there are tiny holes called rod holes. By and far, these are one of the most common basement leak issues that are facing homeowners. These rod holes can easily be repaired by using polyurethane crack injection method.