A thick polyurethane compound is used for manufacturing of the crown molding. This is an architectural compound which is itself semi flexible and totally waterproof. This moulding is used before painting the ceiling or the wall. You can use either nails or architectural adhesives to install this crown molding. You can also paint this like you want just like MDF or wood colour. With any changes in temperature or humidity polyurethane will not expand, wrap or contract. This is a great advantage of this moulding.
It is very much safe to install both in indoors and outdoors. Even in bathrooms or kitchen where the moisture is too much you can install these safely without any issues. This material will not ever rot and you don’t have to fear of any growth of mildew or mold as it will not. This doesn’t absorb any moisture. It is highly durable and as well as light in weight. You will need the following tools to install it –