“Repairing and Preserving Your Adobe Home”
by Roy E. Spears
copyright 2002-2014. All rights reserved.
Copying, pasting, editing, and/or sharing electronically without prior permission from the author is strictly prohibited.
“Should I apply a sealer to protect my adobes?”
This is perhaps one of the most controversial questions in the world of adobe, with strong opinions voiced on both ends of the spectrum. I am always amazed at the brilliance of arguments that come out of both sides of the question and can understand the viewpoints presented by both camps. Yet again, what is true for one type of adobe is certainly not true for all types of adobe, and this chapter will strive to put things in their relative perspective.
First, the case against sealing adobe, and at this point we must define at least three words to properly get a grasp on the issue: sealers, water repellents and breathability.
The first two, sealers and water repellents, are often wrongly used to describe two very different products. A sealer is far different from a water repellent; a sealer is a liquid (most of the sealers in past years were oil [thinner] based, but the majority are now water-based) that is applied to a substrate to make that substrate waterproof. The term waterproof also needs defining, for it is a term that is often carelessly thrown around and has come to mean something different that what the word actually means. When you waterproof an object, your intention is that you do not want water to come in contact with this particular item.
To illustrate this, let’s use a pair of boots as our example. If I want these boots to be waterproof, that means that I do not want to have wet feet when I walk through mud puddles in these waterproofed boots. Waterproof means just what it says, which is that water can not come in. None. Not a drop. I don’t want wet nor even damp socks when I walk through a mud puddle. I want completely dry socks, and this is why I wear waterproof boots. Webster’s defines this word as “that [which] keeps out water; so that water will not penetrate.”
Unfortunately, waterproof does not mean waterproof to many companies that sell their waterproofing products or services. The term waterproof has become so generalized and such an accepted part of our English language that we throw it carelessly around and use it to describe a plethora of things. No one is as guilty of abusing the true definition of the word than the big companies that make water repellents.
A water repellent does exactly what it says, i.e., it repels water, but repelling water does not necessarily mean that water will never get through. Let’s use the illustration of the boots again: if I choose to wear a pair of water repellent boots, expecting them to keep my socks dry, I will be quite disappointed in those boots if I spend any length of time sloshing through mud puddles. These boots may keep my socks dry for a short period of time, but the fact is, sooner or later, I am in for wet feet. Making something water repellent is not the same thing as making them waterproofed. Water will penetrate through a water repellent if the water steadily and continuously comes in contact with the surface of the item.
When you walk into Home Depot and look at a can of Thompson’s Water Seal (the one with the seal bouncing a ball on his snout), you will no doubt find the words “waterproofer” on there. But this is not true, for Thompson’s Water Seal is not a waterproofer but a water repellent, and shame on them for trying to sell you and I a product that will not do what the exact definition of the word states it will do.
Many people, not thinking about these play on words, assume, as I once did, that applying a product labeled a waterproofer on, for example, an adobe wall, will cause it to be impervious to the damaging effects of water. This waterproofer, after applying it in strict accordance with the directions on the label, causes me to believe that when it rains my adobes will never get wet. They will remain as dry as if this wall was built inside my house, surrounded by four walls and covered with a roof. Nothing could be further from the truth.