Cheap Dimpled aerofriendly polyetilene plastic or Drainage Layer
 

Yesterday I found a cheap and eaasy way of doing underbody belly pans with a dimpled surface.
2m x 20m roll costs around 49€ in a DIY hardware and construction materials store, I don't know if it is made in china one or any details (I found at Bricomart Bricomart France,Italy, Poland and Spain only).
The cheapest coroplast ("policarbonato de doble hoja") that I found was about 20€ 2m x 1 m pieces, gray PVC 3mm 1 m x 2 m 63€ and transparent Polycarbonate of high quality and durability 2 mm pieces of 1.25 m x 2 m at 162€.
Magic words are "lámina drenante".
http://teoriadeconstruccion.files.wo...8122010248.jpg
Magic english word also exists and they are: "drainage layer".


Some links with pictures, data, and garden installation in spanish:
Google search of Lámina Drenante -pictures-
impermeabilizacion « teoria de construcción
TECHMO
http://www.techmo.es/pdf/ft/FT_TECHMO%20LAM%20DREN.pdf
http://www.techmo.es/pdf/ft/FT_TECHM...DREN%20MAX.pdf 320KN/m2 resistance.
http://www.presasl.com/fichas/Drentemper.pdf high resistance 320 to 500 KN/m2
Impermeabilizacion Madrid, Cubiertas, Cubiertas Ecologicas, Cubiertas Fotovoltaicas, Goteras, Humedades, Losas, Filtraciones, Aislamientos

Some links in english:
Pictures of drainage layer Google Search

That's interesting. Is it heavy stuff?

Density is somewhere between 0.91 to 0.97 g/cm3 , I remember that the rolled layer aproximated is a cylinder of 0.15m3, so aproximately 140 kg or less because of air, etc.

My instincts say the dimples might be too big for any real benefit... but then again Mythbusters totally showed us on that one! :P