The Trowel Mastic by Cromar is a heavily-bodied, bituminous mastic that delivers exceptional filling and gap-bridging properties on various roofing substrates. It's brewed by Cromars Scientists to be used for maintenance and remedial work, acting as an impervious, waterproofing mastic that repairs small gaps, cracks and tears into the surface. Surfaces that this product excels on include;
- Roofing Felt
- Asbestos Cement
- Metallic Guttering
- Metallic Drainpipes
Before commencing the application, you should prepare the surface to ensure optimal results are achieved. You should clean and remove any oil, dust, dirt, grease, organic growth, etc, that's present, drying the surface afterwards. If you've got any bolt heads exposed, wire brush them to remove the rust before sealing them down with the mastic. If the surface is highly porous, a bituminous primer should be applied prior to ensure the trowel mastic can adhere correctly.
You may lubricate your tools using either white spirit or paraffin, which will aid in the application process.
- Using either a trowel or putty knife, scoop the Trowel Mastic from the container and apply it directly to the gap.
- Force the Trowel Mastic into the gap, ensuring it makes contact with every crack and crevice.
- Smooth out the Trowel Mastic, leaving a smooth, flush finish.
- If you're filling a gap more significant than 3mm, apply this product with fibreglass scrim and then cover it with another coat.
Limitations and Notes
- This product should be applied at a rate of 2mm thickness for optimal results.
- Drying times depend on the thickness of the Trowel Mastic applied and ambient temperatures.
- Any tools used can be cleaned using White Spirit.