Stormdry as Part of a Flood Resistance System

This was a laboratory test carried out by the research & development department at Safeguard Europe in 2010.

Test Aims

Stormdry had been proven to stop water penetration from wind driven rain, in both the lab and in real world testing. The research & development laboratory at Safeguard Europe was tasked with finding out if Stormdry could be beneficial as part of a flood resistance and/or flood resilience system. The research & development team carried out the following test.

Test Method

The British Standard recommended depth of 5mm for water penetration testing (BS EN ISO 15148:2002) was not considered to be representative of the kind of pressures present during a flood event. Due to the maximum guideline height of a flood resistance system being 600mm (Planning Policy Statement 25, Page 149, Figure 6.2), it was decided to test for water penetration up to this depth.

A single skin brick wall was constructed, using standard Fletton bricks, a 5:1 sand:cement render & plasticiser. This wall was then left to dry naturally for 12 months, allowing for stabilisation of the structure and better representing a real-world exterior wall. A large scale water pressure tube of 120mm diameter was constructed and attached to the wall by means of a water proof sealant. For each stage of the test, the tube was filled with water to a height of 600mm and the water level was allowed to reduce over time, while the results were monitored and recorded.

The test was performed 3 times, with the wall in 3 different states. The wall was allowed to dry and the products were allowed to cure between each test. The three stages were:

1. Untreated Wall – The wall was left in its original state and was not treated by Stormdry products in any way.
2. Stormdry Masonry Protection Cream only – The wall was treated with Stormdry but the pointing was left in its original state.
3. Stormdry Masonry Protection Cream + Repointing Additive No.2 – The wall was treated with Stormdry and repointed using Stormdry Repointing Additive No.2.

Results

The results of the test for each different stage were as follows:

1. Untreated Wall – The first test showed the untreated wall suffered from severe water penetration under pressure. Water droplets could be seen on the other side of the wall within 5 seconds. The water level had dropped by more than 300mm, or 50% of the original height, within 6 minutes. It took 8 minutes 23 seconds for the water level to drop to 200mm.
2. Stormdry Masonry Protection Cream – The second test showed that Stormdry Masonry Protection Cream on its own does provide a benefit to flood resistance at lower pressures. Initial flow rates at 600mm were similar to test 1 but it took 8 minutes 49 seconds to reach 300mm, an additional 3 minutes 23 seconds more than test 1. It took more than double the time of test 1 for the water height to reduce to 200mm at 18 minutes and 35 seconds.
3. Stormdry Masonry Protection Cream + Repointing Additive No.2 – The third test showed that Stormdry Masonry Protection Cream, used on a wall that had been repointed with Stormdry Repointing Additive No.2, provides a tremendous benefit to flood resistance at all tested pressures. The water level did not change at all during the measured period.

Conclusion

The results show that water penetrates through an untreated Fletton brick wall very quickly. The majority of the water came through at the mortar joint, specifically along the bottom straight edge of the bricks. This is because the cement in the mortar shrinks as it dries out, meaning that, over time, the mortar starts to de-bond with the adjacent bricks.

Stormdry Masonry Protection Cream, used on its own, does help reduce the water flow rate very significantly, especially at lower water pressures. At high pressure, however, the water finds its way through small cracks and voids in the mortar, created by the process of cement shrinkage.

Where the Stormdry range was really shown to be effective was when Stormdry Masonry Protection Cream was used in conjunction with Repointing Additive No.2. The repointing additive gives the newly repointed mortar flexibility, which resists the cement shrinkage that would normally cause de-bonding with the bricks. Providing there are no serious cracks in the bricks themselves, Stormdry Masonry Protection Cream & Repointing Additive No.2 prove to effectively eliminate water penetration at the water pressure tolerances expected of a flood resistance/resilience system. This means that Stormdry Masonry Protection Cream & Repointing Additve No.2 are both valuable additions to any flood protection system.