Installing Substrate Under Countertop
- Cutting tool for plywood
- Hot Glue Gun
- Identify and source substrate material (generally plywood) of the required thickness. The thickness will equal the height of the additional drop that was added to the countertop edge. (i.e.- If you added a 1" drop to create a countertop with a total edge thickness of 1.5", you will need to use 1" thick plywood).
- Cut and prep 2.5" wide strips of plywood.
- Measure and cut strips to length such that you fully frame around the inside edge of your countertop. Hold your substrate between 1/8" and 1/4" off of your buildup to allow room for expansion and contraction. Glue into place using alternating dabs of silicone and hot glue.
The hot glue serves as a temporary bond that holds the substrate to the countertop while the silicone has time to fully cure. Never adhere your substrate only using hot glue. Silicone is absolutely required for a long term bond.
- Glue in horizontal 2.5" cross supports if remaining unsupported countertop depth exceeds 12". As a general rule you do not want greater than a 12" span of countertop without a cross substrate.