We were at the factory tour last week and they were building your model, I would have said our model but there are some subtle but noticeable changes since 2015. I just checked and I only got one picture of the roof and it is after it is bonded and only the end. I think you are right, it is just Styrofoam but you would most likely be going right across an A/C Duct if you poke through it to the area above the microwave. I have emailed Rockwood with questions before and they have always answered but one time the answer didn't really answer the question...
If you go to this link and use the drop down under Travel Trailers and select Rockwood Windjammer the page will have a list of contacts and a form to fill out for questions. I used that form to ask questions like that.
Forest River RV Contact Us - Forest River, Inc.
this is the only pic I took of the roof.
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2016 Windjammer 3006WK - Sold July 2018
2002 Lance Lite 835EC TC - Sold July 2015
2010 Dodge Ram 2500, 4x4, Diesel, Front Hitch, Air Lift 5000 Rear Air Bags, Sold Mar 2019.
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