I am making a swimming pool cake and planning a tile look using small squares. I was planning on mmf or candy clay for the tiles. While swimming at party venue(local aqatic center) yesterday, I realized there was a higher humidity level than I am used to. This got me thinking my first choice are not the best choice. The cake is for my sons birthday party at the center it is planned at full sheet with half being a dummy cake so we dont compromise the design or have too much cake. Trying to get as much prep done as baseball season here starts soon and there goes my spare time. The tiles are on sides of cake and edged around the "water".

My son wants strawberry shortcake. Can I use stabized whip cream under whatever I choose? The cake probably be pound or white torted with fresh berries and hopefully stablized whip cream. 

What if you added tylose to the mmf to firm it so that it won't wilt, or use gumpaste?

Never used tylose before not even sure I can find it local. Cake making here is a bit behind the times and our cake shop changed owners and just sucks. Looks like a shopping  trip or an amazon order is in my future.