Cinder Block Waterproofing

What Is Cinder block or Concrete Block?

Concrete block waterproofing, or what used to be called cinder block waterproofing, is basically the same thing; it’s just that the name has evolved over the years. These blocks used to be made out of the tailings from steel mills, or cinders, they were called. Actually, they were just bits and impurities that floated to the surface of the liquid steel. These bits of waste were collected and recycled with some concrete to make these blocks. Now the whole system is automated, and the proper amounts of sand and gravel bits are mixed with nearly dry concrete into blocks that can stand up by themselves as soon as are pushed out of the machine. Blocks were used back in the day to make foundations for houses. Later, foundations got bigger and turned into basements for houses. (That’s what got me into basement waterproofing!) In order to turn these blocks into the foundation wall, there has to be a footing laid on the bare ground inside the hole that they build for the basement. It wasn’t until after World War II that cinder blocks started to be replaced by poured concrete walls. I don’t know who invented the poured concrete wall but I know that Adolf Hitler perfected it. His engineers came up with ways to pour concrete 20 feet thick, loaded with steel for reinforcement. He needed his concrete to be impervious to everything, and so the poured concrete walls are much stronger than the old cinder block. Some of that know-how leaked into the building business around here.

Poured Concrete and Concrete Block Walls Leak Differently.

As you know, concrete block walls look different from poured concrete walls. When concrete blocks are set in place, masons use a bit of mortar between them to cement them together. In addition, the blocks are stacked in a zigzag fashion to make a finger joint zigzag. That locks them together more efficiently. The mortar that holds the cinder blocks together is not as strong as the block itself. So it will break before the block does. Plus it does not stick like glue. Mortar does take somewhat, but comes loose after time. This creates open spaces in the block foundation wall. Spaces can be both in the horizontal joints and in the vertical joints. That makes room for water to come in through the side of the block all way from the top to the bottom. You’ve probably seen a concrete block, and noticed that they are hollow. When the water leaks in through the cracks it has to fall all the way to the bottom of the wall. This fills the bottom holes of the blocks with water. The water in the soaked blocks leaks through to the inside of the basement. This is where people may try to hide the resulting chemical and mold buildup with paint which actually makes things worse. Most cover-up paints are made of latex, which is organic and an enjoyable snack any black mold.

How We Fix Concrete Block Walls with This Leaking Mess

It’s pretty simple to fix this, but to do a good job; you really need some experience somewhere. Plus it is physically tough work. The basic principle is that you have to get the water out of the bottom of the concrete block. You do this by drilling 5 holes along the bottom part of the bottom block and let them drain. We have put these holes in walls like this and had hundreds of gallons leak out of them and flood the floor we’re working on. Then you have to connect these holes with a pipe to a drain, and better, a sump pump. I would say, in this case, a sump pump is mandatory. That, basically, is how we do it.