Page 8 - ProInstaller Sept-Oct 2021
P. 8

Focus on Resilient:



        Working with Self-Leveling




        Underlayments







        By Ray Thompson, Jr.


              lmost all self-leveling products recommend the   be installed the next day. Care must be taken to not allow
              use of primers to work as a bonding agent.  Make   the underlayment to dry too fast.  Underlayments that dry
        Asure to use either a porous (absorbent substrate)   too fast tend to exhibit surface cracks. The way to prevent
        or a non-porous product for ceramic, quarry tile, terrazzo,   this is to monitor the four temperatures listed earlier. The
        marble, steel, lead, and cut-back adhesive residues.  key to self-leveling is to keep the temperatures around
                                                            70° Fahrenheit (21.1° Celsius).
        Additives
        On special types of substrates, an additive may be
        recommended for metal and or cutback adhesive
        residue. The additive will provide additional bonding
        strength and will allow a little bit of deflection into the
        mix.

        Temperatures
        Temperature control is vital to successfully using self-
        levelers. With self-levelers, heat is your worst enemy.
        When you are dealing with a self-leveling product make
        sure to monitor four temperatures:


            1.  Ambient temperature
            2.  Slab temperature
            3.  Powder temperature
            4.  Mix water temperature
                                                                             Priming the Surface
        If any of these temperatures exceed 70° Fahrenheit (21.1°   When priming, it is necessary to know if the surface is
        Celsius) it will prove to be detrimental to the application.   porous or nonporous as the type of primer is different.
        In warm weather, the pour may have to be done early in   Using a primer ensures a good bond to the substrate and
        the morning or late in the evening when temperatures   can prevent future problems.
        are cooler. Powders can be stored in a cool place and
        the mix water container can be filled with blocks of ice   When mixing, it is critical to use the correct water to
        to cool the mix water. Heat causes the self-leveling mix   powder mixture. Mixing is done by adding the correct
        to prematurely stop flowing, usually giving a set time of   amount of powder to a premeasured amount of water.
        less than five minutes and making it difficult to get the   Once the powder is added to the water, power mix with a
        product in place.                                   heavy-duty drill at about 650 RPM for approximately two
                                                            minutes. Power mixing will break surface tension in the
        In cooler conditions, the self-leveler will have a slower set   water, allowing for a smooth mix that will flow easily for
        time. Beware of temperatures below 50° Fahrenheit (10°   about six to eight minutes. Once the mixing is complete,
        Celsius), as it will have an adverse effect on the mix.  pour the mix out the container onto the floor without
                                                            delay. The approximate time from when the powder hits   Photos courtesy of Ardex Americas
        Drying                                              the water to the stop of the flow is about 10 minutes at
        Drying usually takes about two hours before you can   70° Fahrenheit (21.1° Celsius). You must allow time for
        walk on the newly installed surface. Resilient floors can   spreading and smoothing.
                                                                                                      Continued
        8  PROINSTALLER MAGAZINE  •  SEPTEMBER/OCTOBER 2021
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