Contrary to popular belief, water damage is not the worst enemy of concrete. Acid damage, which can occur when acid rain falls on concrete surfaces or acidic substances are spilled on the surface of a structure, poses a greater threat to large-scale concrete applications.
Concrete is strong against water damage because it consists largely of calcium silicate hydrate (C-S-H), an interlocking network of microscopic particles that form through a chemical reaction between calcium and silicon in the presence of water. However, as these microscopic particles bond and harden into a stone-like mass (hydrated lime) over time, they also become more brittle and susceptible to cracking under sudden stress. This applies mostly to structures with large spans such as bridges and elevated highways where expansion and contraction due to temperature changes cause the concrete to crack. If not caught in time, these cracks will lead to water seeping through and dissolving away at the C-S-H until the entire structure is compromised beyond repair.
Is concrete ruined if it gets wet?
Yes, but only if it is exposed to enough water for a long enough period of time. This can happen when concrete surfaces are not properly sealed and waterproofed or as the result of structural damage caused by flooding, earthquakes and other extreme conditions. Concrete becomes weakened and spongy as the C-S-H within its structure dissolves into a liquid solution that leaks through cracks and pores in the surface, rendering it soft and crumbly much like sand at the beach after sitting in the sun for too long.
Concrete does not weaken overnight; it takes months before water damage becomes visible on well-sealed surfaces, even years before moist patches appear over large assemblies such as walls and foundations. This makes it difficult to tell whether concrete has been damaged by water or is simply deteriorating on its own.
Generally, the best indicator of water damage is new cracks appearing over previously smooth, undamaged surfaces. However, even if these are present it doesn’t necessarily mean that water damage occurred at some point in the past; recent rainfall can also cause new hairline fractures to form on dry concrete as moisture seeps into its microscopic pores and causes them to expand ever so slightly under stress.
Can anything be done about water damage?
Yes, but only after it occurs. Like most problems associated with aging & deteriorating structures, there is little homeowners can do about extensive forms of water damage other than cut their losses and replace sections of the damaged assembly or structure before they cause any further harm.
Concrete patches and sealers like Silaflex, a liquid concrete composite, offer some relief from less extensive forms of water damage such as white efflorescence, which is a common sign of water from the surrounding soil seeping to the surface through hairline fractures in the concrete. By filling in these cracks with a strong adhesive resin, Silaflex prevents moisture from coming into contact with the C-S-H within the concrete and dissolving it away with time. This can extend the life of a deteriorated structure by up to 50 years in some cases!
Can’t the concrete absorb water?
It can absorb a lot of water, but not nearly as much as other porous building materials such as brick and mortar. This is why water damage to concrete structures is rare compared to wood and plaster.
Of course, this does depend on the surface from which the water seeps into the structure. If it’s through cracks in the foundation or damage to a waterproofing membrane for example, then all bets are off and it will probably cause extensive forms of water damage over time.
Concrete vs Brick: Which One Is Stronger?
Typically speaking, brick buildings develop leaks faster than those built with concrete because these only have a single layer of cement & soil between them and Mother Nature whereas brick homes typically have 2-3 layers of protection against the elements. This is one of the main reasons why brick is used more often for outdoor structures such as garden walls, which are exposed to constant rainfall and extreme temperatures in some cases.
Although both materials are pretty durable when handled properly, only one offers superior protection against water damage. As mentioned above, this happens thanks to its ability to form a dense & waterproof layer over time when exposed to moisture in the environment. Once again, this would be concrete in most cases because it has several layers of cement separating it from surrounding soil or porous masonry surfaces that actually absorb water into their pores rather than just sheer off as concrete does under droplets of rain or sprinklers turned on by accident. Still, don’t let water sit against either surface for extended periods of time, especially if they are close enough for it to cause real damage.
