Important Considerations Before Waterproofing Roof Decks

To ensure the best waterproofing results for roof decks, it’s essential to pay attention not only to application techniques and waterproofing materials but also to key considerations before starting the waterproofing process. Below are crucial points to consider before you begin waterproofing a roof deck!

1. Preparing the Concrete Surface Before Waterproofing

For older concrete surfaces, follow these steps to enhance the effectiveness of waterproofing:

• Chisel off excess concrete and clean the surface to remove any sand, dust, or grease.

• Use a high-pressure water spray to clean the concrete base thoroughly, removing dirt, grease, and other contaminants.

• Finally, fill in any large depressions or gaps in the concrete and tiles.

Note: For highly uneven surfaces, use a grinder to smooth and clean the surface. This step is crucial as an uneven surface can puncture waterproofing materials under heavy load.

2. Treating Expansion Joints and Cracks

Expansion Joints:

• Chisel and clean the joints using a dust blower.

• Prepare the surface thoroughly, removing oil and dirt with a brush or handheld tool.

• Once the joints are clean, inject joint sealant into the structural joints.

(Note: The surface must be clean and free of dust.)

Cracks:

• For cracks, roughen a 2 cm width around the centerline of the crack and 1–1.5 cm depth along the length using a specialized chisel.

• Prepare the surface thoroughly, removing oil and dirt with a brush or handheld tool.

• Fill cracks with sealing putty.

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3. Handling Pipe Penetrations Through the Floor

Treating pipe penetrations through the floor is the final step in preparing the surface for roof deck waterproofing. Here’s how to handle it:

• Chisel around the pipe collar, making a 5-10 mm gap from the pipe edge and a depth of 5 mm.

• Wrap an expanding tape around the pipe collar.

• Pour non-shrink grout around the pipe collar.

• Seal around the collar with Neotex Pu Joint sealant.

• Apply Gavazzi fiberglass mesh around the pipe collar.

• Coat the fiberglass mesh and pipe collar with a subsequent waterproofing layer.

4. Selecting Suitable Waterproofing Materials

After preparing the surface as outlined above, you’re ready to start the roof deck waterproofing process with confidence. However, to achieve optimal results, choose a waterproofing material suitable for your specific project. Determine the project’s characteristics to select the appropriate material. Additionally, study the application methods for each type to ensure proper and effective use.