Sandy mortar is usually caused two ways. In the old clay tile blocks of the old homes built before about 1930, a lime-based putty mortar was used (Portland cement, which has a stronger binding agent, is used today). Water or acid leaches the lime out of the old mortar and eventually the mortar must be replaced. This mortar starts to break down after forty or fifty years. In newer block in homes made with modern cinder block sandy mortar is usually caused because the wall was built in the winter when temperatures fall below freezing before the mortar had time to fully set. The molecular bonds in the mortar are not as fully formed because the water needed to completely strengthen them was frozen and not available to complete the process. This usually shows up after a period of years as “sandy” mortar, which can be broken down by a light rubbing. Crumbling mortar can also be caused by too much moisture from shrubs and vines too close to it.

Sandy mortar is covered in Section J of The Home Waterproofers Manual – Home Waterproofing A to Z. Remember, in the waterproofing business it’s “buyer beware”. Most salesmen get a percentage of the sale and don’t consider it their job to save you money. They charge as much as they can. If they see a problem that can be fixed inexpensively, they won’t mention it, but will only talk about preventing serious damage and try to frighten you into signing a big contract.

You can save thousands of dollars and many headaches by learning what is going on first. Often what looks like an expensive and serious problem may not be. Once the problem is explained, solving it is just common sense. I’ve used the knowledge I’ve put in The Home Waterproofers Manual – Home Waterproofing A to Z every day to fix water problems. It will work for you too.

But remember, when dealing with salesmen, in the waterproofing business it’s “buyer beware”. Most get a percentage of the sale and don’t consider it their job to save you money. They charge as much as they can. If they see a problem that can be fixed at low cost, or one that has a simple solution, they won’t mention it, but will only talk about “preventing serious damage” and try to scare you into signing a big contract.