How to Waterproof Your Interbloc Structure

Waterproofing an Interbloc system, made up of precast concrete blocks, is a crucial step in ensuring the longevity and durability of the structure. Interbloc systems are widely used in settlement ponds, retaining walls, bins, and bunkers, among other applications.In this blog, we'll discuss how to properly waterproof an Interbloc system, why it is important, and why we recommend using sealants for most Interbloc structures.

How to seal an Interbloc structure

1. Use a suitable sealant: The first step in waterproofing an Interbloc system is to apply a sealant to the interlocking layers of the blocks. The sealant should be applied in layers to ensure complete coverage before proceeding to the next step.
2. Seal the joints: The joints between the precast concrete blocks in an Interbloc system are a common point of water ingress. To prevent water from entering through these joints, they should be sealed with the same sealant. The sealant should be applied to the joint in a continuous bead before the structure is put into use. It is important not to apply too much sealant to the joint as it can cause the precast concrete blocks to shift and move, leading to structural issues.
3. Regular maintenance: Waterproofing an Interbloc system is not a one-time process. It is important to conduct regular inspections and maintenance on the system to ensure that the waterproofing remains effective. This includes checking for any cracks or damage to the sealant.

(The highlighted are shows an example of where you'd add sealant if you wanted to waterproof your Interbloc structure)

Why it’s important to waterproof

Waterproofing an Interbloc system is vital because it helps to protect the structure from water damage. Water ingress can cause the system to weaken and deteriorate over time, leading to costly repairs or even complete failure. Waterproofing also prevents structural damage such as rusting of steel reinforcement.

Why we recommend sealants for most Interbloc structures:

Sealants are an excellent choice for waterproofing Interbloc systems because they are easy to apply and can provide long-lasting protection. Sealants are flexible and can move with the structure, which helps to prevent cracking and damage to the waterproofing. Finally, sealants are a cost-effective solution for waterproofing Interbloc systems, making it an attractive option for those on a budget.

Waterproofing the Waterview Tunnel’s Settlement Pond

A well-known Auckland roading project, the Waterview Connection, needed settlement ponds to store and treat liquid from the tunnelling process. Interbloc was chosen for it's combination of engineering and modularity. 

In order provide a watertight solution, sealant was added to the joints of the 1.8m high walls. It was sealed using shotcreate, allowing for a temporary solution to hold the liquid. When the settlment ponds were no longer needed, the sealant was removed and the blocks sold back to us via the buyback guarantee. 

By taking the steps to waterproof an Interbloc system using a waterproofing sealant, and not applying too much of it, you can ensure that the Interbloc system will remain in good condition for many years to come.