Waterproofing in desert landscapes, such as Arizona, isn’t always a popular subject, but I find that there are always new problems with each visit.  Although the average rainfall in Phoenix is nine inches per year, when it does rain, it often pours; causing traffic issues, flash floods, and building damage.  Water is a very soft compound but, powerful.  Water can cut through granite forming mountains, natural rock designs, and the Grand Canyon.  It doesn’t take much water to cause a lot of damage.  Preventing water damage could save you thousands of future dollars and headaches.  Here are a four tips to help the pocketbook.

  1. Waterproof your decks.

If you have concrete decks that aren’t waterproofed, you need a waterproofing system and here’s why.  Even though there is little rain in Arizona, what amount there is still causes damage.  When water lands on a concrete deck, it soaks in and remains there until it evaporates away.  (We have all witnessed a darkened substrate after a rain until the Sun is able to draw out the moisture.)  There are two issues that occur when concrete decks are unprotected by a proper waterproofing system; surface damage and internal structural damage.  Surface damage occurs each time water invades concrete and leaves, causing erosion.  This immediately weakens the deck substrate, causes more ponding water areas (ponding water compounds water damage) and increases the amount of water intake for the next rainfall.

The second issue, internal structural damage, is a major issue and happens over a longer period of time.  As water is taken up by the concrete, the moisture going in and out is travelling causing weakness with expansion and contraction.  This moisture also affects the steel rebar that is installed within the concrete to keep its strength.  As moisture reaches the rebar, it causes the rebar to rust and expand (no contraction) beneath the surface.  During the expansion, it begins to push away the concrete causing cracks and ultimately failure with large amounts of concrete breaking apart.  This results in a very expensive renovation and serious safety hazard.  Refer to the picture for a building in Phoenix that has this issue.  This may result in a high six to seven figure renovation, depending on its severity and how many decks are involved.

  1. Choose the right product.

Urethane waterproofing systems are the most popular systems used in Arizona for concrete or plywood decks.  Maintenance for these systems seems to be easy however, there is one major trick that most do not know.  There are two types of urethane top coats; aromatic and aliphatic.  Aromatic urethanes are not UV resistant and delaminate in the Sun.  Aliphatic urethanes are UV resistant and should last about 3-5 years after application.  When a urethane waterproofing system requires maintenance due to cracking, or delamination, most people unknowingly use the lower cost aromatic urethane to remediate the problem.  That will last about 6 months to 1 year before it requires attention, again.

When undergoing a remedial, or renovation, be sure to contact the manufacturer to get the right product for your use.  Aliphatic urethane may be more expensive, but it will outlast the continual maintenance over its lesser counterpart saving money in the short and long run.

  1. Remove unnecessary deck surface coverings.

Artificial turf, large mats, or indoor/outdoor carpeting will eventually cause premature failure.  Personally, I wouldn’t allow it and it can negate any warranties if used over a waterproofing system.   If it is used, it should be removed immediately after a rain allowing the “mat” and deck surface to dry.  If this is not properly maintained, the water will remain between the deck surface and the covering, accelerating damage to the deck area and eventually cause premature failure of the deck or waterproofing system.

  1. Create a maintenance calendar.

A maintenance calendar is the best way to prevent premature failure and over expenditure to installed waterproofing systems.  Don’t wait for tenants or owners to complain, by then, it’s too late.  I suggest a routine schedule of inspecting each waterproofed area three times a year, minimum.  Schedule inspections after heavy rains and/or after a long period of dry weather.  Look for cracks, delamination, ponding water, and debris build up. Keep these areas clean from debris (dirt, leaves, etc.) stains, and check underneath pots and other dead loads.

Even in dry climates, any amount of water will damage structures without prejudice.  These are just a few of the most common ways to prevent future expenditures and maintain a healthy structure.


Originally posted for the Community Associations Institute – Central Arizona Chapter.

Subscribe to our Newsletter

Stay in touch with us and be the FIRST to know about new products, upcoming events and training – straight to your inbox!

Contact to Listing Owner

Captcha Code
Scroll to Top