Healthcare buildings require waterproofing systems that can perform reliably over the long term with minimal risk of failure. In active hospital environments, roof leaks can lead to ceiling damage, moisture-related deterioration, maintenance disruption, and hygiene concerns.
At Assunta Hospital, Petaling Jaya, ARCHTECH was engaged to carry out flat roof waterproofing works covering 2,607 square feet. The objective was to protect the exposed roof area with a more dependable waterproofing solution suitable for a critical-use building.
This project highlights how the right combination of site assessment, system selection, surface preparation, and workmanship quality plays a major role in long-term waterproofing performance.
Project Overview
Project Type: Healthcare Facility
Location: Assunta Hospital, Petaling Jaya, Selangor
Area Covered: 2,607 sq ft
Waterproofing System: Primer + Torch-On Membrane
Application By: ARCHTECH Waterproofing Specialist
Why Waterproofing Is Critical for Hospital Flat Roofs
Flat roofs in hospitals are exposed to constant weathering, including heavy rainfall, heat, and UV exposure. When waterproofing starts to deteriorate, the impact can go beyond the roof surface itself.
In healthcare facilities, roof leakage can contribute to:
- ceiling stains and internal water damage
- repeated maintenance issues
- moisture-related deterioration to surrounding building elements
- disruption to internal operations
- added risk in sensitive or high-dependency areas
Because of this, hospital roof waterproofing should not rely on short-term patch repair alone. It requires a system that is appropriate for the roof condition, correctly installed, and designed for long-term performance.
Site Conditions and Waterproofing Problems Identified
During the inspection of the flat roof area at Assunta Hospital, several common waterproofing risks were identified.
1. Deteriorated Existing Waterproofing Layer
The existing waterproofing layer had aged and deteriorated over time, reducing its ability to resist water penetration effectively.
2. Hairline Cracks on the Roof Surface
Surface hairline cracks were present, creating possible entry points for water. Even minor cracks can become a bigger problem over time when exposed to repeated rain and heat movement.
3. Uneven Roof Surface
Unevenness across the roof surface increased the risk of water ponding. When water remains on a flat roof for extended periods, it places more stress on the waterproofing system and may shorten its service life.
4. Continuous Exposure to Sunlight and Rain
As an exposed flat roof, the area was subjected to constant UV radiation, rainfall, and thermal movement. These conditions accelerate deterioration when the waterproofing system or detailing is inadequate.
These findings showed that a superficial repair would not be enough. A more robust waterproofing approach was needed to improve durability and reduce future leak risk.
Why a Primer and Torch-On Membrane System Was Selected
After reviewing the site conditions and building requirements, ARCHTECH recommended a primer and torch-on membrane waterproofing system for this flat roof.
Torch-on membrane is commonly used for exposed flat roofs because it can provide a durable waterproofing layer when installed correctly over a properly prepared substrate.
Why this system was suitable for the project
- strong resistance to outdoor weather exposure
- good durability under sun and rain cycles
- reliable bonding when applied over a properly primed surface
- sealed overlaps that help reduce weak points between sheets
- suitable for flat roof areas that require long-term protection
For critical buildings such as hospitals, system selection is important. Choosing the wrong solution, or applying a good material on a poorly prepared surface, can still lead to premature failure.
How the Hospital Roof Waterproofing Work Was Carried Out
All works were carried out by ARCHTECH’s trained in-house waterproofing specialists using a structured application process.
Step 1: Surface Preparation
The roof surface was first cleaned thoroughly to remove dust, loose particles, and surface contaminants. Proper preparation is one of the most important stages in waterproofing because poor adhesion often begins with an unprepared substrate.
Step 2: Primer Application
A primer was applied to improve bonding between the roof substrate and the torch-on membrane. This step helps create better adhesion and supports the membrane’s long-term performance.
Step 3: Torch-On Membrane Installation
The torch-on membrane was then installed using controlled heat application to achieve proper bonding to the substrate.
Special care was taken to ensure:
- proper adhesion across the roof surface
- securely sealed overlaps between membrane sheets
- consistent application quality across the treated area
- proper detailing at edges, joints, and transition areas
These critical detailing areas are often where waterproofing failure begins if workmanship is rushed or installation is inconsistent.
Why Workmanship Matters in Torch-On Membrane Waterproofing
Torch-on membrane performance does not depend on material alone. It also depends heavily on how the system is installed.
Common causes of torch-on membrane failure include:
- poor surface preparation
- inadequate priming
- insufficient heat application
- weak bonding to the substrate
- poorly sealed overlaps
- rushed detailing at joints and edges
For this reason, the success of a torch-on membrane system is closely tied to installer skill and quality control during application.
For the Assunta Hospital project:
- the works were carried out by trained and qualified specialists
- installation followed a structured waterproofing process
- certified materials were used
- quality checks were conducted during and after the application
Because the waterproofing system was installed using certified materials and controlled workmanship, the completed works are backed by a 10-year warranty, providing added assurance for the building owner and facility team.
Waterproofing Outcome for the Assunta Hospital Roof
Upon completion, the flat roof was protected with a newly installed waterproofing system designed for exposed conditions and long-term reliability.
The completed waterproofing works helped improve protection against:
- water ingress through the roof surface
- ongoing weather exposure
- moisture-related ceiling damage
- future maintenance disruption linked to roof leakage
For a healthcare facility, this type of long-term roof protection is especially important because it helps reduce avoidable building issues before they affect internal operations.
Key Lessons From This Hospital Roof Waterproofing Project
This project at Assunta Hospital reinforces several important waterproofing principles.
Correct system selection matters
Not every waterproofing solution is suitable for every roof. The system must match the building condition, exposure level, and performance requirement.
Surface preparation is critical
Even a good membrane can fail early if the substrate is not properly cleaned and prepared.
Workmanship determines long-term performance
Torch-on membrane waterproofing depends heavily on correct application, sealed overlaps, and careful detailing at vulnerable areas.
Flat roof problems should be addressed early
Cracks, aged waterproofing, and ponding risks are warning signs that should be handled before they develop into more serious leakage and internal damage.
Looking for a Flat Roof Waterproofing Specialist in Petaling Jaya or Selangor?
ARCHTECH provides waterproofing solutions for residential, commercial, industrial, and institutional buildings, including exposed flat roofs that require durable long-term protection.
Our approach focuses on:
- accurate on-site assessment
- suitable system recommendation based on roof condition
- trained in-house waterproofing specialists
- certified waterproofing materials
- workmanship quality designed for long-term performance
If you are facing recurring roof leakage, aging waterproofing, or ponding issues on a flat roof, the first step is to assess the actual condition properly before choosing a repair method.
Need help with flat roof waterproofing?
Contact ARCHTECH for a roof assessment and speak to our team about the most suitable waterproofing solution for your building.
About ARCHTECH Waterproofing Specialist
With over 10 years of experience, ARCHTECH provides waterproofing solutions for residential, commercial, industrial, and institutional buildings.
Our approach combines:
- Accurate site assessment
- Certified professional-grade materials
- Trained in-house specialists
- Proven waterproofing systems
- Delivering results designed for long-term reliability, not short-term fixes.
FAQ: Hospital and Commercial Flat Roof Waterproofing
Is torch-on membrane suitable for hospital flat roofs?
Yes, torch-on membrane is commonly used for exposed flat roofs in commercial and institutional buildings when long-term durability and weather resistance are required. Its suitability still depends on the roof condition, detailing requirements, and correct installation.
Why is primer important before torch-on membrane installation?
Primer helps improve adhesion between the roof substrate and the membrane. Without proper priming, bonding strength may be compromised, increasing the risk of premature failure.
What are common signs that a flat roof needs waterproofing repair?
Common warning signs include recurring roof leaks, ceiling stains, deteriorated existing waterproofing, visible cracks, ponding water, and repeated patch repairs that do not solve the problem for long.
Why does flat roof waterproofing fail?
Flat roof waterproofing can fail due to aging materials, poor surface preparation, incorrect system selection, bad detailing, poor workmanship, and ongoing ponding water.
Is a surface-level repair enough for an aging flat roof?
Not always. If the existing waterproofing system has already deteriorated or the roof has cracks and uneven areas, a surface-level repair may not provide durable long-term protection.
What type of buildings commonly use torch-on membrane waterproofing?
Torch-on membrane is widely used on flat roofs in hospitals, commercial buildings, institutional facilities, factories, and other buildings with exposed roof areas.
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