Internal Pressure in Hurricanes: How a Broken Window Can Tear Off Your Roof in Riviera Maya

What Is Internal Pressure in a Hurricane?

Internal pressure is one of the most dangerous — and least understood — factors in structural behavior during a hurricane.

When a storm system strikes a building, high-speed wind exerts pressure on all exterior surfaces. However, the real risk appears when that wind manages to enter the interior of the property.

This happens when:

Once inside, the wind becomes trapped and begins to pressurize the interior of the building, acting like a balloon being forcibly inflated.

The Combined Effect: External Pressure + Internal Pressure

To understand why this is so destructive, the full dynamic must be analyzed:

This phenomenon creates a double effect: the roof is pushed from the inside and sucked from the outside at the same time.

This point is critical. It is not just about strong wind. It is about a system of opposing forces acting simultaneously on the structure.

Why Roofs Fail First

In most structural collapses during hurricanes, the roof is the first element to fail. This occurs because:

When internal pressure increases, the roof stops behaving as a stable structural element and begins to act like a lid under pressure. If it is not designed to resist uplift loads, it can detach in a matter of seconds.

This is why "the roof looks solid" is not useful information for predicting its behavior. A roof well built for vertical loads may not be designed at all for a force acting in the opposite direction — upward, from both sides simultaneously.

The Critical Point: A Single Opening Can Collapse the Entire Structure

One of the most common mistakes in properties in Mexico is thinking that partially protecting a home is enough. It is not.

It only takes one window failing for the entire system to collapse. An unprotected opening allows:

This means a property with 90% protection can fail just as badly as one with no protection at all.

What Is the Difference Between 90% and 100% Protection?

The following breakdown illustrates how the coverage percentage does not predict the outcome proportionally — what determines the real risk is the condition of the least-protected opening:

This phenomenon is described as "all or nothing": the coverage percentage does not predict the outcome proportionally. The outcome is determined by the condition of the least-protected opening.

The Role of Certified Anti-Cyclone Systems

This is where professional hurricane protection systems in Mexico come in.

Certified anti-cyclone systems do not only stop impacts — they completely seal openings, prevent wind entry, keep internal pressure stable, and protect the structural integrity of the property.

Options such as anti-cyclone tarps, anti-cyclone screens, and certified anti-cyclone systems are designed to withstand Category 5 protection conditions, including extreme pressure and high-speed debris.

Why This Is Critical for Hotels and Developments

In large-scale projects — such as hotels or commercial developments — the risk is even greater. It is not just about structural damage, but also:

A failure caused by internal pressure can compromise multiple units at the same time. This is why developers who understand the risk do not look for budget solutions, but for systems designed under international standards such as those from Florida.

In multi-unit developments, anti-cyclone protection has a property that is rarely discussed: it is a shared asset, not an individual one. If one unit fails to protect its openings and suffers internal pressurization, the affected roof may be a roof shared with other units. One owner's decision to "save" on protection can create structural risk for neighbors who did invest in certified protection.

Common Mistake in the Riviera Maya

In many properties in the Riviera Maya, the approach remains aesthetic or basic:

This creates a false sense of security. But in a real hurricane, especially Category 4 or 5, these systems fail. And when they fail, they allow exactly what must be avoided most: wind entering the interior.

Decision Framework: How to Assess the Risk of Internal Pressure in Your Property

Step 1: Map All Openings — Without Exception

The question is not "how many windows do I have?" — it is "how many air entry points exist?"

Step 2: Identify Your "Weakest Link"

From the full list in Step 1, identify:

That opening — not the average of all of them — is what determines the real internal pressure risk of your property.

Step 3: Evaluate Your Roof for Uplift Loads

Regardless of opening protection, confirm:

A roof well designed for uplift, combined with a 100% sealed envelope, offers the most robust protection possible against this mechanism.

Step 4: For Hotels and Developments — Evaluate by Unit, Not Just by Building

In multi-unit structures:

This is why certified anti-cyclone protection in multi-unit developments is not an "individual responsibility" — it is a decision that affects the shared structural integrity of the entire project.

Key Facts About Internal Pressure

For more information, visit our hurricane protection section, our residential solutions, or check our frequently asked questions.

Conclusion

Internal pressure is one of the leading causes of structural collapse during hurricanes, and at the same time, one of the most underestimated.

It is not the wind alone that destroys a property. It is the combination of poorly contained forces.

Understanding this phenomenon completely changes how protection must be approached. It is not about resisting the hurricane from the outside. It is about preventing it from getting in.

Frequently Asked Questions

Does internal pressure only occur in very strong hurricanes?

No. It can occur in intense storms if there is an opening that allows wind to enter. The intensity of the hurricane determines the magnitude of the pressure generated, but the mechanism can be triggered from lower categories if there is a significant entry point.

Do impact-resistant windows eliminate this problem?

Only if they are certified and correctly installed. Otherwise, they can fail under impact or pressure — and "resistant" without specific certification for impact and cyclic pressure does not guarantee that the window will remain sealed throughout the entire event.

Do anti-cyclone tarps really work?

Yes, as long as they are certified systems installed correctly. They are designed to prevent the entry of wind and debris — that is, to specifically prevent the first step in the sequence that leads to internal pressurization.

Is it necessary to protect all openings?

Yes. A single unprotected opening can compromise the entire structure. This is not a "best practice" recommendation — it is a direct consequence of how internal pressurization works: it is triggered by one entry point, not by a percentage.

Does this also apply to hotels and large buildings?

Absolutely. In fact, the risk is greater due to the scale and complexity of these structures — more openings means more potential failure points, and shared structures mean that the failure of one unit can affect others.

How does this relate specifically to roof design?

The roof is the element that receives the combined effect: aerodynamic suction from outside and upward pressure from inside. A roof specifically designed for uplift loads, combined with a sealed envelope, reduces risk from both sides of this equation.

What if my property already experienced internal pressurization in a previous event?

A complete structural evaluation is important — not just of the openings that failed. Internal pressurization may have generated fatigue or damage in roof-to-wall connections that are not externally visible, even if the roof did not fully detach — and those points may be more vulnerable in a future event.