One reusable silicone faucet knockout that will create a 1-3/8" hole which will work with most standard faucets. It will also create a 2-1/2" pocket that is 1" beneath the surface to fasten hardware in. This will accept most faucets and spouts. Must be used with 1/2" substrate and our standard 2-1/4" forms. If using EuroForms, please use the EuroForm Knockout.
To install, use a 2-5/8" hole saw. Push the knockout up through the hole from the underside of the cement board until the 3rd ring hits the bottom of the cement board. Check to make sure the top of the knockout is flush with the top of the forms. For most applications we normally like to split the difference between the sink opening and the backwall so that you have the most concrete possible around the faucet. If you have a deeper countertop or smaller sink, please check to make sure that the faucet is lined up properly over the sink.
WARNING: some of the newer faucets require larger than 1-3/8" hole. Please check your facucet. If you need a larger hole, you can wrap the top of the knockout in electrical tape to increase the diameter.