25 Feb 2015

Experts may be missing something!

I picked up a real-estate magazine while I was in a waiting room the other day. In the magazine was an article under the heading “Expert Advice”. In this article the owner of a company involved in concrete in general, and concrete foundations specifically, was advising us on how to protect our investment in concrete. I like where he is going so far!

The writer continues by describing that, what I have also found to be a common misunderstanding, concrete can “leak” without being cracked. That concrete is porous, though seems dense; and repeated saturations can soften your concrete. Now, I am glad to hear someone that makes their living selling and installing concrete, admit that concrete is porous. As opposed to the architect that argued that concrete is not porous! I am pretty sure that it takes more than just repeated saturations with water to soften concrete. When the salts carried by the water re-crystallize inside the concrete, there is enough force involved to “tear” the concrete “matrix”. But, the end result is the same, damaged or “softened” concrete as a result of water incursion.

I am in agreement with the concrete expert writer of this article, partly! He suggests a “waterproofing membrane” to be added at the time of construction. He seems to be saying this because of the high cost of repairing a crack later? Cracks come in different sizes and, therefore, different cost of repair. Personally, if I have a crack serious enough to require repair, I would be complaining to the installer of the basement/foundation! So that leaves us with preventing water coming through the “not” cracked concrete. The statement that I agree with the concrete contractor is the need for waterproofing. My concern is that he is suggesting a sheet product that must be attached to the exterior of the concrete, or even worse, a “tar” like substance that must be “painted” on to the outer surface.

With a choice of waterproofing methods, would you choose a “tar/paint” like substance that will dry, crack, shrink and finally let moisture through? Would you choose a rubber like sheet system that must be attached by nail or screw to the exterior of the concrete, and at some point during installation will need to be “spliced” to itself? Or would you choose a non toxic, non hazardous, “sprayable”, penetrating, permanent solution that can be applied on the inside or outside surface of the concrete and cannot be separated from the concrete by any means? Would you choose the waterproofing solution that fills or “plugs” the “pours” of the concrete so that no future fluid can pass through or enter?

The article goes on to explain that the writer also recommends proper grading and snow removal to prevent rain or snow melt from entering through the concrete, and that his business offers these services. Obviously these recommendations are meant for structures built with no waterproofing added to the concrete. But wait, tar has been used on the exterior of concrete basements as a waterproofing membrane for decades, I guess it doesn’t work! Fear not, Seal-It has a solution that can be used to treat any age concrete, from the interior of the structure, and it won’t stop working, ever!

There is more advice on concrete maintenance in this article. We now read the author’s warnings on concrete in your garage, driveways and walkways. The writer describes hazards to concrete in “our harshest season”. So, of course, he is talking about winter in Canada, but I would add, if you live in a part of the world that experiences temperatures below the freezing temperature of water you can expect these problems. When ice melting methods, i.e. salt, are used on roadways and walkways, these substances can be carried into your garage, for example, and lead to damaged concrete.

When salt is used on sidewalks and outdoor concrete to increase traction, what is happening is that ice is converted to liquid at temperatures below the freezing temperature of water. Since we have established that concrete is porous, this liquid we have created will be absorbed and will freeze at slightly lower temperatures inside the concrete. The problem here is that when water becomes ice it expands, and when salt water freezes it expands even more. This expansion happens with such force that it cannot be contained by the concrete. Basically an explosion in the concrete!

What about a heated garage? Obviously there shouldn’t be any concern about damage from freezing. But the salt that could be brought in on your vehicle will react with any reinforcing metal imbedded in the concrete, and, the salt that makes it into the concrete floor will behave in the same manner as the salt in the ground water discussed earlier.

This is where the author loses me, he isn’t suggesting anything more than sweeping, mopping, and using vinegar to neutralize the salt that manages to get deposited on your concrete. I am not prepared to take such a chance and miss some of the salt and water that will ‘soak” into the concrete before I can get to the mop!  I don’t want to do so much work; mopping the floor every time I move my vehicle in and out of the garage.

It makes much more sense to treat the concrete with Seal-It Concrete Sealant and prevent any water, or salt water, from being absorbed ever.