The foundation to any home is the backbone for promoting longevity and adding to the stability of your home’s value over time. The different types of foundations have different symptoms when dealing with water seepage.
All foundations are vulnerable to hydrostatic pressure, which is caused by a spring or water table pushing up from below. When the water table or spring reaches the basement floor, pressure begins to build up below the structure as the floor impedes the rise of the water table or spring. This pressure will relieve itself by entering through seam lines and cracks in the floor and wall of any foundation type. The pressure build up can easily reach 60 PSI – to get an idea of that pressure level, try stopping your kitchen faucet with your thumb and you’ll quickly see that your foundation is unable to defend itself from the intrusion of water seepage. Let’s quickly look at each of the foundations types to evaluate the pros and cons of each.
Poured Wall Foundation
A poured wall foundation on a footer is one of the best values in the construction of homes. By maintaining the grade, these foundations can be impervious to water seeping in through the wall. They are, however, susceptible to stress cracks, usually on either side of a window. Often in this case, the stress crack will run from the corner of the window down to the floor. The homeowner can maintain leakage or seepage by simply keeping up with the grade. Should hydrostatic pressure build up below, you will often see seepage where the wall and floor meet, and there may be cracks in the floor as well as cracks in the wall. Sealing cracks in the wall just sends the water higher up the crack to spill out at another place in the line of the cracks.
Concrete Block Foundation
A concrete block foundation is a worthy, cost effective way to construct the foundation walls to your home. However, the block wall construction is more vulnerable and care should be taken to maintain the foundation wall. Again, by maintaining the grade, top water can stay clear from flowing back to the foundation wall and entering through the commonly seen mortar cracks. Once water stands along a wall, the puddle builds weight and the weight of the water will send it through the mortar cracks then to cascade through the webbing of the blocks building up at the base.
Water in the block is not a good thing for this type of foundation. As water builds in a block, the weight of the water is fused through porosity of the block. Once the water is evaporated on the other side, you will often see a white residue remaining. This residue is the lime inside the block, often called the glue that holds your blocks together. This is most definitely a deterioration process and over time will affect your block wall.
Remember, block walls are built to hold weight up, usually at the high end of the envelope of tolerance. They are not strong with lateral pressure and you want to be careful how blocks are weakened over time. Hydrostatic pressure will affect the sub-floor and footer the same way it will a poured wall. However, the up flowing water now has hollow cavities inside the core of the block to store all the damaging weight of the water.
The fieldstone foundations of the past are as strong as anyone could wish for, the older homes usually lack in ceiling height from the older relics and these foundations were built much differently from today’s foundations. To begin with, unlike a poured wall or block wall, there is no backfill area that will settle over time. Rather they dig a large hole and use the undisturbed soil as side wall support for the stones, this soil is as dense as anyone would wish for. The fieldstone walls usually extend a foot or two beneath the basement floor, which is also resting on undisturbed soil.
Again, maintaining grade is important. Should hydrostatic pressure rise up on a fieldstone foundation, the water will use the wall as the conduit for water pressure. Remember, the concrete floors are resting on undisturbed soil and the walls are backed up against undisturbed soil, making the stone wall itself the weakest point allowing water to flow with the least resistance possible. This constancy will weaken the mortar between the stones over time.
In any case, Basement Waterproofing has a solution for wall seepage with our Bentonite Injection method. And should your home be affected by hydrostatic pressure, we have the solution for that as well. We offer free estimates to any homeowner and all contracts provide a lifetime transferable warranty for your home.