Advice & Technical Support.

Why Is My Roof Leaking Even After Waterproofing?
 

By Miya Waterproofing & Roof Repair Experts

 

A leaking roof after waterproofing is one of the most frustrating experiences for homeowners. You expect the leak to stop — yet the next rainfall brings the same (or worse) problem.

 

The truth is: a leak after waterproofing does not always mean the waterproofing failed. It often means the root cause was never identified.

 

In this article, we break down the 7 most common reasons roofs still leak after waterproofing, and how Miya Waterproofing Experts solve them permanently.

 

1. The Waterproofing Was Applied to the Wrong Area

 

Most roof leaks don’t come from where the water drips inside — they come from:

  • Valleys
  • Flashings
  • Roof ridges
  • Parapet walls
  • Cracked tiles or loose sheets

 

If the contractor only waterproofed the visible wet spot inside the ceiling, they didn’t fix the real problem outside.

 

✔ Our Solution:

 

We perform a full roof moisture trace, checking:

  1. Water pathways
  2. Roofing joints
  3. Hidden cracks

  4. Capillary channels

  5. Wind-driven leak entry points

 

2. Poor Quality Waterproofing Products

 

Some cheap waterproofing paints or sealants last only 3–6 months—especially under South African heat.

 

Common failures include:

  • Fading
  • Cracking
  • Delamination
  • Loss of elasticity

 

✔ Our Solution:

 

We use UV-resistant, flexible membrane systems:

  1. Torch-on membranes
  2. Polyurethane waterproofing
  3. Acrylic membrane systems
  4. Bitumen-based sealants

 

These systems offer 5–10 year durability.

 

3. Incorrect Application by Unskilled Contractors

 

Research shows 40% of waterproofing failures come from application errors, such as:

  • Applying coating on a dirty or dusty surface
  • No primer
  • Too little waterproofing product
  • Wrong product for the roof type
  • Waterproofing applied over damp areas
  • Not sealing corners and edges properly

 

✔ Our Solution:

 

Miya technicians follow a strict technical application process:

  1. Cleaning
  2. Priming
  3. Membrane bonding
  4. Multiple coats
  5. Cure-time monitoring

 

4. The Leak Was Caused by Roof Damage, Not Waterproofing

 

Some leaks come from:

  • Cracked tiles
  • Rusted IBR sheets
  • Broken flashings
  • Loose ridge caps
  • Damaged valleys
  • Rotten timber
  • If the structure is damaged, no waterproofing can fix it.

 

✔ Our Solution:

 

We evaluate roof structure, sheets, joists, valleys, and ridges before applying waterproofing.

 

If repairs are needed — we do them first.

 

5. Poor Roof Design or Water Flow Issues

 

Some roofs naturally collect water or push water to weak spots.

 

Examples include:

  • Flat roofs with no slope
  • Incorrect gutter installation
  • Water pooling on parapets
  • Blocked run-off points

 

These structural issues cause repeat leaks.

 

✔ Our Solution:

 

We recommend:

  • Adjusted slope levels
  • Improving drainage
  • Installing water channels
  • Re-doing gutters if required

 

6. Waterproofing Was Only Done in One Area

 

Many roofs have multiple leak points that show up one at a time.

 

If a contractor waterproofs only one spot:

  • Another weak area will leak next
  • The homeowner thinks the same leak returned
  • But it's actually a new leak

 

✔ Our Solution:

 

We offer complete roof waterproofing systems, not patch jobs.

 

7. Expansion & Contraction Cracked the Waterproofing

 

South African weather extremes cause roofs to expand during heat and contract at night.
This movement cracks:

  • Old membranes

  • Rigid waterproofing paints

  • Poorly applied coatings

 

✔ Our Solution:

 

We use flexible systems that handle temperature movement, ensuring long-term leak prevention.

 

Final Word: Waterproofing Is Not Paint — It’s a System

 

Waterproofing, when done correctly, involves:

  • Proper diagnosis
  • High-quality materials
  • Professional application
  • Structural inspection
  • Layered protection

 

This is why Miya Waterproofing Experts deliver durable, guaranteed solutions that stop leaks permanently.

 

Book a Waterproofing Inspection Today

 

Get expert diagnosis + full repair plan.

 

🌐 www.miyaconnection.co.za
📲 WhatsApp: 066 036 1296