Why Basements Leak Water?

Basements that leak water in through the joint where the floor and wall meet after a rain or snow melt are considered to be, the most common wet basements. More than 90% of the wet basements leak water from the walls and the joint where the floor and wall meet. Most basements rarely leak water up through the floor. Surface water collects and builds up in a pocket around the foundation causing hydrostatic pressure. Water then is forced through the joint where the floor and wall meet.

Preventive tips for leaky basements

The cause of a wet or damp basement can be minor, readily apparent, and easily corrected. Here are some probable causes and possible solutions:

Problem: The source of the water cannot be identified.

Solution: To determine whether the water is seeping in from the outside or condensing inside, tape a twelve-inch square of aluminum foil to a wall that is prone to dampness, sealing all four sides as airtight as possible. In a day or two, if the side of the foil that was against the wall is wet, the problem is seepage. If the outside is wet, it's condensation.

Problem: Lawns that are flat or slope toward the house permit surface water to drain down against basement walls. Water enters through cracks or other openings in the walls and causes wet spots on the walls or standing water on the floor.

Solution: Slope the ground away from the outside foundation (about one inch per foot). Extend the slope for at least ten (10) feet. Seed it with a good lawn grass. Sodding is a common practice and prevents the washing away of newly graded areas during heavy rains. Where a large area of land slopes toward the house, surface drainage should be intercepted and redirected some distance from the house. Dig a shallow, half-round drainage ditch or depression designed to route the water around the house. Sod the ditch or plant grass in it. If even a shallow ditch is objectionable, drainage tiles, with one or more catch basins at low spots, may be installed.

Problem: Defective, clogged, or nonexistent gutters and downspouts allow roof water to form puddles, or wet the soil near or against basement walls, and enter through cracks or openings in

Problem: Defective, clogged, or nonexistent gutters and downspouts allow roof water to form puddles, or wet the soil near or against basement walls, and enter through cracks or openings in the masonry.

Solution: Install gutters and wherever needed keep them free of debris. Where leaves and twigs from nearby trees may collect in a gutter, install a basket-shaped wire strainer over the outlet or place screening across the length of the gutter. Repair gutters and downspouts regularly. To prevent concentration of water at the point of discharge, use a concrete gutter or splash block to carry the water away at a slope of one inch per foot. Also, consider extending from rain gutters away from the outside foundation. Roof water can also be piped underground to a storm drain, dry well, or surface outlet, fifteen (15) feet or more from the house.

Problem: Dense shrubbery and other plantings around the basement walls prevent good ventilation.

Solution: Trim shrubbery so that soil gets more sunlight and dries quicker. When digging up the plantings, remove any pieces of masonry, mortar, or other material buried near the house.

Problem: Unprotected basement window wells act like cisterns during heavy storms, permitting water to seep in around window frames and below windows.

Solution: Windows below grade should be protected by metal or masonry window wells, with bottoms consisting of gravel to permit good drainage. Clear plastic bubbles are available to cover the entire window well like an awning.

Problem: Moisture produces condensation (sweating) on cool surfaces in the basement, particularly walls, floors, and cold water pipes.

Solution: Insulate the water pipes. Promote good ventilation-sunlight and free movement of air can quickly dry out a basement. Ventilation should be regulated according to the weather conditions. During hot and humid weather or long rainy spells, windows should be closed because the outside air will probably contain more moisture than the basement air. Heat the basement during the winter. During hot weather, use air conditioning.

Concentrate On The Source Of The Problems

If every logical way of eliminating wetness fails to produce a dry basement, do not waste time or money on random potential solutions. Finding the cause of the problem is absolutely essential to its cure. The hardest type of water problem to correct is one created by faulty construction practices at the time the house was built. Proper drainage is a crucial consideration in selecting the site for a new house. This includes not only the drainage of surface water but also drainage of any subsurface or ground water that may already be present, or that may accumulate over a period of time and be blocked from its normal course of flow by the new construction.

If the subsurface or ground water level is close to the underside of the basement floor slab, water rises through the slab by capillary action, producing dampness. If the subsurface or ground water level is higher than the basement floor, water leaks in through the walls and floor or enters by capillary action, causing standing water in the basement and, at times, dampness in the rooms above.

Under ideal conditions, a house should be situated so that even during rainy seasons the subsurface or ground water level is at least ten feet below the finished grade.

In some cases, it is impossible to completely eliminate dampness from a basement whose construction did not take into consideration the basic principles of good drainage. In some cases only after soil borings have been done can anyone knowledgeably predict which, if any, course of action has a chance for success.

Weigh Alternative Methods Of Treatment

An accurate diagnosis of the main cause of persistent basement wetness may lead to a recommendation of one or more of the following actions:

A. Redirect Water Away From Foundation

The various exterior waterproofing barriers have varying levels of effectiveness in protecting the outside wall areas. But wall anti-leaking barriers do not affect water penetration due to water accumulation at the footer or floor level. The ideal solution to this problem lies in directing the accumulation of water away from the foundation or into drainage or pumping systems.

B. Install An Interior Drainage System

To control leakage in the basement, you may install a drainage system on the inner side of the foundation. The floor is broken up along the perimeter of the basement wall and drain tile is placed in a trench that carries the water to a discharge point, or sump pump, which takes the water away from the house. With hollow block walls, holes may be drilled at the bottom to allow the water to pass into the drainpipe and relieve the water pressure. The trench may then be filled with gravel and the floor replaced or recommended.

If installed correctly this system will remove basement leakage water. Channels may also be installed on the basement floor to take the water away through a sump pump.

C. Apply Waterproofing Compounds To Interior Walls

Only in cases where mild and occasional capillary seepage occurs are applications of waterproofing paint or other interior compounds likely to provide any lasting degree of improvement in achieving a dry basement.

Capillary waterproofing materials can be applied to either exterior or interior wall and floor surfaces. If properly applied, they will penetrate several inches into concrete and close off capillaries or minor cracks by forming crystals in the presence of water. You should carefully read the label to determine the waterproofing product's limitations and terms of any guarantee promised. Waterproofing paint is most effective if applied directly over cement; not existing painted walls.

If you don't have gutters installed on your home

You're asking for wet basement

If you do have gutters or downspouts discharging rainwater next to your foundation

You're asking for wet basement

Extensions should discharge the rainwater eight (8) feet from foundation

Appropriate installed basement waterproofing

Be sure you recognize the origin of your water seepage. If you don't have water coming up through the middle of your basement floor, then don't bust up the floor to fix the leakage. There are several systems that relieve hydrostatic pressure without jackhammers trenching through the basement floor or having to haul mud and gravel in and out of your home. Adhered to the floor along the wall can act as a barrier, collecting later from weep holes tapped into the blocks where the floor and wall meet. Water travels along the to a drain or sump-pump. This method could save you hundreds of dollars over an unneeded sub-floor system.

A properly applied waterproof barrier may prevent the water form seeping through the wall, but allow it to seep deeper into the ground until it finally comes through around the footer or basement floor. Thus, it is critical that a knowledgeable and competent engineer evaluate the problem.

Deal with a waterproofing company that has a good reputation in the community, one that has been in business in the same area for several years, and depends on the satisfaction of its clients. Find out if the company is bonded, licensed and certified. Also, find out if the company trains its workforce.

Beware of salespersons or contractors who ask for large payments in advance. Reliable contractors generally do not require more than a minimal down payment.

Obtain written estimates from at least three (3) contractors. Compare the cost of the work to be done, the quality of materials to be used, and the cost of financing the work. Insist that each estimate include the cost of materials and labor and a statement of exactly what the contractor will do and how long the work will take.

Be cautious of the solutions

When choosing your basement waterproofing system, compare different types of remedies. For sub-floor systems there are several remedies to consider. We recommend drain tile along the inside footings in a bed of pea rock. The top of the tile should be set deep enough so the top of the tile is level with the top of the footings. Holes should be tapped in the bottom row of blocks to drain the walls into a low profile system. This allows you to pour the floor using several inches of concrete.

Drain tile or any other high profile system should never be installed on top of the footing. We do not recommend any system that requires the floor to be poured at an angle up the wall as pictured above. Avoid any digging around the outside of your foundation. This disturbs the vital compaction incurred over years of settlement and generates a sponge like condition.

Waterproofing paints and plug-its are rarely used... For good reason. Over time, the lime in the cement promotes growth of mildew between the walls and the paint. Huge boils and blisters form and then paint begin to shale. Install some type of drainage system.