Foam Panel test

I created a foam panel today with 1 inch 4x8 foam. I used screws with washers to hold it on along with glue. I covered some of the washers with the foam "stuff"? Not sure how this is going to work. We will try texturing the panel and painting it to see how it works. 1 inch foam is half the cost of 2 inch foam. If this works for us it will help the budget.