Electric radiant mats were rolled out according to the manufacturer's installation diagram. The longest mat needed to be carefully cut (without cutting the wire) in three places to make 180-degree turns.
An in-floor sensor probe was run to the thermostat so the radiant mat could be controlled by the temperature of the floor, as well as by ambient air temperature.
A glue gun was all that was needed to tack the mats in place so they didn't shift during the installation of the self-leveling compound.
Tapcon screws drilled roughly 48 inches on-center served as benchmarks for the finish elevation of the underlayment.
A story pole and laser level were used to ensure the tops of the screw heads were level. It's time-consuming, but saves effort down the road because it yields a better result.
The underlayment was mixed outside. The crew used a high-speed mixer and an egg-beater paddle to mix it to the right consistency.
The grid of screws helped guide where to dump the buckets of underlayment mix to evenly distribute it.
A float-like tool was used to level the self-leveling underlayment to the tops of the previously installed screws.
As it hardens, the self-leveling material emits a lot of heat and moisture that needs to be vented to prevent damage to the woodwork.
After the underlayment cured overnight, a latex primer was rolled on. This would help the crack-isolation membrane bond to the underlayment.