Liquid rubber roofing system
Liquid rubber roofing is a fully bonded, liquid-based coating which can be applied to most decks straight from the tin. When it cures, it creates a rubber-like, elastomeric, waterproof membrane.
Despite the name of liquid rubber, it isn’t actually made from EPDM rubber. In almost all cases, ‘liquid rubber’ is made from liquid PU (liquid polyurethane). The system is similar, as it makes its own membrane, similar to a reinforced EPDM rubber membrane, but it is a different material.
The System
There are a few different liquid waterproofing systems on the market; here we will use Arboflex PU as an example. The Arboflex PU system is built up of several layers depending on the deck type.
The base layer is the primer (Arboflex PU Primer). This is applied to roof deck substrates, such as concrete, mortar, or plywood, to increase bonding and surface levelling. If you’re installing on OSB, the primer is not required.
The second layer is the first coat of polyurethane liquid (Arboflex PU Liquid Waterproofing), in which a generous coat of liquid (between 65/70%) is applied. If applied onto a sloping surface, it must be mixed with the Arboflex PU Thickener to prevent sagging of the membrane due to its drying time.
The third layer is the fibreglass matting (Arboflex PU matting), which is wet-on-wet rolled into the liquid layer until partially wet. This is done to strengthen the PU liquid.
The fourth layer is the second, and final, coat of polyurethane liquid. This is wet-on-wet applied and done until the matting is fully embedded and there are no visible pin holes. Ensure this is only 30 – 35% of the material above, too thick and you will get bubbles.
The final layer is UV protection (Arboflex PU UV Protect). This protects the system from harmful UV which without would reduce the systems lifespan from 25 years down to 5 / 10 years.
Every product mentioned above can be found in our complete Arboflex PU Liquid Roof Kit, where we have options for all deck types and coverage from as little as 10sq.M up to 50sq.M.
