Materials: Droppar of various size
Description: To make a porthole very cheap in a concrete-to-face view wall. Use “Droppar” jar, put inside the cap some silicone to make it very well sealed. In a concrete wall you have to design on the outer board the exact position of the jar, then tie to the metallic armor of the concrete, when the concrete is being cast, be careful not to cast it upon the jar directly, the aggregate could break the glass. Do not vibrate the concrete but beat the outside of the armor boards but not in the jar position.
After having disarmed the wall, put a veil of silicone in the outside perimeter of the cap.
~ Stefano, Roma