How to Waterproof a Typical Building

Every building is different; some are below the groundwater table, and some are above; some are built in harsh environments, some are not. However, they all have something in common, “Resisting Water ingress” and increase the concrete durability beyond its design life.

Penetron has a full system to treat all your external concrete waterproofing needs from the slab on ground all the way to the rooftop. Below are some of typical areas that can be treated.

Note: Depending on the location of the groundwater table and the warranty request, the details below could be adjusted accordingly. If unsure, please request the Master Penetron Specifications or get in touch with the Penetron Australia technical team for more details.

1. Lift Pits: Apart from the piles, lift pits are usually one of the deepest structures that you can find in your building, hence subject to higher hydrostatic pressure than other elements in the building, which requires more attention for waterproofing. We offer a variety of solutions using different products, for example:

• PENETRON ADMIX in the slab and walls, and one PENEBAR SW waterstop in the construction joints. The tie holes must be remediated with the Penetron products depending on the holes’ condition.

2. Slab on ground: Basement slabs are very different to one another, some have pour-breaks and some don’t, some are poured first then the walls and some poured against the walls, etc. Refer to an example below:

• Where the slab meets the walls, you use one PENEBAR SW waterstop and PENETRON ADMIX in both the slab and the walls, and
• If there are pour-breaks, use one PENEBAR SW waterstop in the construction joints.

3. OSD Tanks: Different products can be used, for example:

• When the structure is in-situ, use PENETRON ADMIX is the slab and walls, and 2 layers of PENEBAR SW waterstops in the construction joints. For an extended warranty, use an additional line of defence by applying BLOCKSEAL (Cementitious membrane) internally. Please note that Penetron can also treated potable water and Sewage tanks by using a different set of products such as PENETRON coating and/or BioMic.

4. Shotcrete Walls: You can easily design a waterproof and durable shotcrete wall by following the right steps.

• Use edge boards around your daily pours.
• Add PENETRON ADMIX in the concrete mix.
• Install either PENEBAR SW or PVC Hydrostops in the construction joints.
• “Hit-and-Miss” approach to eliminate cracking within the shotcrete panels (See below).

Every concrete naturally shrinks and cracks; however, there are many known ways to reduce the concrete shrinkage such as the use of PENETRON ADMIX, Shrinkage limited cement, concrete shrinkage reducers, proper curing by using compliant methods and products such as SUPERCURE HR, etc. Therefore, it is important to prepare your shotcrete for the worst-case scenarios by introducing construction joints, and their locations are as follows:

Multiply the minimum shotcrete thickness by x 25 as the best case, and by x 35 as the worst case to place a construction joint.

Example: Assuming that the minimum shotcrete thickness is 200mm.

Best case: Install a construction joint every 200 x 25 = 5000mm.

Worst case: Install a construction joint every 200 x 35 = 7000mm.

If using the construction joints only, use the hit and miss technique following the maximum lengths’ guide above. See below:

If using the combination of the construction joints and false joints, the same maximum lengths’ guide above should also be adopted by applying the hit and miss technique too. See below:

Request the Master Penetron Shotcrete recommendations document from Penetron Australia website.

5. Precast and Tilt-up Walls in basement: Precast walls can be waterproof and so can the horizontal and vertical joints.
Request the Penetron-Precast document. See an example below:

6. PVC Walls: PVC walling systems came a long way to become one of the most preferred systems in construction, thanks to its ease of installation and cost as well as to their waterproof skin they are built with. Penetron Australia have created several documents to specifically address the waterproofing needs of the different supplier’s products by illustrating the different scenarios with sketches and photographs. Request your free copy today from the Penetron Australia website. Request the Penetron-PVC walling system document, 

In-situ walls similar. Refer to the basement slab on ground details above.

7. Swimming Pools: Swimming pools’ design needs to consider the water seepage in two directions, the chloride attacks, the durability of the structure, the TVOC of the products used, and the quality of the water for the health of the users. Penetron can offer all the above as a minimum. See below a sample design:

8. Planter Boxes: Planter boxes can be designed in in-situ, Precast, PVC walls, Blockwork, Bricks, etc. Penetron offers a solution for all the above. See an example below:

9. Balconies and Roof Slabs: This is another very critical part of the building that requires waterproofing and durability. Before you select your waterproofing system, ask the following questions:
a. Is the slab exposed to UV?

b. Is the slab covered with tiles, pebbles, membrane, soil, etc?

c. Is the slab over habitable areas?

d. Is the slab subject to high levels of abrasion (High traffic from tyres, foot, or both)?

e. Any pipe penetrations through the slab or construction joints to the walls/upstands?

f. Has it been designed with sufficient falls to drains?

Once you get answers to all the above questions, then Penetron can put forward the right system to accommodate your design needs with the required warranty up to 25 years.

The typical products that can be used are PENETRON ADMIX, PENETRON, BLOCKSEAL, PENEBAR SW waterstops, PVC HYDROSTOPS, membranes, etc. Submit your project for assessment through the Penetron Australia website.

The above are a few examples of areas that we have covered; however, the Penetron system is as large as our experience and imagination can take us.

Please get in touch with Penetron Australia for any further information.

Hacene Baleh

National Technical Manager

Penetron Australia