Is Your Structure Monsoon Ready?

Monsoon season is almost here. Within a months’ time, the entire Indian subcontinent will experience heavy rains and dangerous conditions. While the arrival of monsoons is linked with the new harvest season, it’s also time to re-examine the safety of all our structures: buildings, factories, schools, bridges, sport complexes, etc.

Rainy season brings not only constant rain but also high winds. Both natural forces are dangerous to the building envelope and structural integrity, as façade, waterproofing, and structural systems are penetrated by corrosive moisture.

These risks are immediate and can cause long term problems. For a few lucky structures, the intrusive moisture can dry out after rainy season; But for vast majority, the deterioration continues once the water finds a path to breach the façade elements. We know that the corrosion may slow during the dry season, but it will begin accelerating again during the next monsoon. After a few cycles of wet and dry seasons, we really start to notice concrete spalling and rusting reinforcements, and by then it might be too late to salvage.

Let’s quickly look at common causes for monsoon-related deterioration and some simple protective measures that we employ to combat them.

Water Related Issues

• Water causes and accelerates corrosion of steel elements and reinforcement bars. Good quality concrete offers protection to bars inside, but water can seep in to slowly reach the reinforcement when the concrete starts to crack.

• Stagnant water on roof is a clear recipe for disaster. It adds additional weight on roof and facilitates water penetration through micro-cracks that could lead to collapse.
• Building basements are designed to be watertight, so check them closely for leaks. Water seeping through basement walls or the basement slab indicates serious structural issues and  warrants immediate attention by a structural expert. Even if the walls and slabs are structurally sound, water may still manage to reach the basement and this stagnant water can cause dangerous rebar rusting.

• Steel members, specially welded or bolted joints, are under serious threat during the rainy season. The continuous presence of water can break through protective coatings and lead to corrosion.

• Soil erosion during flooding is a serious structural threat. Shallow foundations are more prone to erosion damage.
• Flooding or soil softening can also cause uneven foundation settlement, leading to structural cracks in beams and columns.
• The structural frame supporting a building’s façade is also susceptible to rain damage. This connecting frame isn’t visible from the outside and needs to be inspected for corrosion after heavy rains.

• Growth of vegetation during rainy season is a common problem. Plants with tiny roots penetrate deep inside the structure creating a pathway for water and air to creep inside the concrete slab, beams and columns.

High Wind Related Issues

• When building façade and roof elements are severely damaged by wind, water can access interior systems and cause structural damage. Installing façade insulation will help deter this water seepage.
• Light weight roofs attract very high pressure during windstorms. These systems, like the tin roofs we see on many factories, are vulnerable to losing bolts in high winds if not designed properly, providing another major entry point for water.
• Some façade elements or sheet roofing can become flying hazards. This is a major threat to structural stability as well as loss of life.

Solutions to Combat Water Intrusion

Here is the list of some basic solutions that can be applied before rains to safeguard our buildings.

• Check leaky or blocked drains and plumbing systems.

• Add waterproofing to your roofing structure. There are multiple solutions available in the market for all types of roofs. Base your choice on your budget and your building’s condition.
• If your roof already has a waterproofing coat, look for the cracks in waterproofing. A timely repair can suspend the corrosion for a few years.
• Clean the roof drainage system. Dry leaves and bird’s feathers blocking the drainage pipes are main reasons for water stagnation at roof.
• Check the steel elements and consider applying protective paint on them.
• Keep an eye on plant growth. Its best to pluck them while they are not bigger than a few centimeters.
• Most importantly, do not allow water to stagnate in any area of your structure. Pay special attention to your roof, balconies and basements. Immediately clear any stagnant water within the structure after flooding.

Next Steps for Existing Damage

Building enclosure specialists can help you solve your waterproofing and façade related issues.  When you notice issues—like cracks in columns or gaps between walls and beams—immediately approach a structural engineer to evaluate your structure for repair, rehabilitation or retrofitting.

Engaging the right specialist now can save you from a greater financial burden down the road. We, at Walter P Moore, offer both building envelope and structural solutions. Our experts have served various types of structures at all stages of deterioration, reversing the effects of damage and giving a fresh life to each structure. [Example-1, Example-2]  

While we enjoy the bliss that the monsoon brings, let’s also take care to safeguard our built environment from its long term effects.