Masonry Magazine August 1965 Page. 10
WET BASEMENT
So the foundation is finished. It's straight and true in all directions, right on the button as far as dimensions are concerned.
What do you do now?
If you are building foundations in the desert, call for the crew that throws the backfill in the hole. Your job is finished, your problems at an end.
But, if you don't build in the desert, you have rain and moisture problems to contend with. You had better figure on some form of waterproofing or dampproofing.
But, what type?
There are many types and services you can buy. They are all good up to a certain point. Then, the better they are, the more they cost.
Probably the easiest, and the cheapest, is the sprayed-on black asphalt. The service truck backs up to the foundation and in a matter of an hour or so there is a uniform black film of tar around every bit of the foundation that is below ground level. Is it good? Reasonably so. The tar coating puts a thin surface film of water resistant asphalt over the blocks and over the joints. If you do a good job and have several coats put on, it will plug up some of the smaller voids that you will find in all concrete block. It's cheap. But, it can't plug up large crevices or voids, it wasn't planned for that. It's a wonderful dampproofing to keep moisture from the ground from entering the basement and making it musty. But, when that foundation settles and cracks the film of tar cracks and there is an open entryway for all kinds of moisture problems.
Let's invest a little more. The fiber type spray-on coatings. They are four or five times thicker, have fibers to plug bad spots in the block. It is a little resilient, will give a bit and still hold out water when the foundation starts its settling. But it will shear when the foundation cracks and there is your entryway for water.
How about membranes? Real good, particulary where you know from past experience that water problems abound. These membranes wrap sheets of paper or fabric around the foundation, really give you defense in depth against seepage problems. If you find any evidence of moisture seepage in your excavation, you will want a multiple membrane for certain.
At the footing granulor bentonite is used. The footing is beaded with approximately one pound of material per lineal foot. Notice the lap of the panels so that a good secure protection is secured.
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New panels of bentonite that are being marketed today. Methods of attaching to foundation can vary. This photo shows the panels being held in place before back fill with wood loth and nails. Other methods of attaching are mastic and air powered stapler.
MASONRY.
August, 1965