Investigating Water Absorption in Roofing Tiles

Water absorption testing plays a crucial role in evaluating the amount of moisture roofing tiles can potentially absorb. Excessive water absorption can lead to undesirable consequences such as cracking in the tiles. Hence, this test is essential to determine the suitability of roofing tiles for various applications, especially in environments prone to rainfall, freezing, and thawing cycles. The ideal roofing tile should have a considerably low absorption capacity.

Global Standards and Testing Methods

To ensure uniformity and reliability in water absorption testing, various international codes, such as the American Standard for Testing Materials and the Indian Standard, have been established. One of the prominent methods outlined by the American Standard for Testing Materials (ASTM) is ASTM C373. According to this standard, non-porous tiles typically exhibit a water absorption range of 0.1-0.5%, while porous products may show absorption in the range of 9-15%.

Aim of the Water Absorption Test

The primary objective of the water absorption test is to determine the percentage of water absorption in roofing tiles. This metric serves as a critical indicator of the tiles’ ability to resist moisture, influencing their overall durability and performance.

Apparatus Required

For conducting the water absorption test on roofing tiles, the following apparatus is essential:

• Balance or Scale: An adequately calibrated balance or scale capable of precise measurements to 0.01 grams.
• Oven: An oven with the capability to maintain a minimum temperature of 150°C.

Specimen Selection

Two tiles are selected from the sample for the water absorption test. These tiles represent the overall characteristics of the roofing material.

Test Procedure

The water absorption test is conducted through the following step-by-step procedure:

1. Preparation: Dry the selected tiles in an oven at a temperature ranging from 105°C to 110°C until they reach a constant weight. After cooling, weigh the tiles (M1).
2. Immersion: Immerse the dry specimens completely in clean water at a temperature of 27±2°C for a duration of 24 hours.
3. Surface Inspection: After the immersion period, carefully wipe off any surface water from the specimens using a damp cloth. Weigh the specimens again (M2) within 3 minutes of removing them from the water tank.

Calculation of Water Absorption

The percentage of water absorption is calculated using the following equation:

W=(M2−M1M1)×100W=(M1M2−M1​)×100 (Equation 1)

Where:

• W: Water absorption of the specimen expressed in percentage.
• M1: Weight of the dry specimen.
• M2: Weight of the specimen after 24 hours of immersion in clean water.

Results

After performing the water absorption test, the calculated water absorption of the given roofing tiles is determined as a percentage, providing valuable insights into the tiles’ moisture resistance properties.