1/4 fanfold

[docchop1]

This year I used fan fold 1/4 inch insulation as an underlayment. 30$ for 200 square feet.
http://www.menards.com/main/building-ma ... c-5778.htm
It might provide some small thermal break but I really was only concerned with it's resiliency and making the floor feel absolutely fantastic. It worked and it feels great underfoot.



[attachment=0:vnjbgguy]poolunderlay.jpg[/attachment:vnjbgguy]

 

[mrodgers]

What do the creases from the folds feel like? I thought of FFF, but thought it would be too thin first, and second, thought the folds wouldn't be good.

FFF, particularly the Dow Protection Board (I think, it use to be called BluCore) is what many folks use for scratchbuilding RC airplanes.

 

[docchop1]

I thought of the folds too but was prepared to just deal with them. Turns out that the weight of the water has compressed the foam to a uniform thickness and I cant find the folds. I used sand last year and it felt ok but imho this feels much better. It has just a little bit of softness and doesn't leave heel and toe divots like sand can. So far so good.