Need help figuring out a suitable base for a 2ft x 8ft cage

[factorunknown]

I am upgrading my current setup for my guinea pigs from a 2x4 to a 2x8, and am trying to figure out what I can use as a base. I wanted to use corrugated plastic but Idk how to manage to make a base that big with it, and the bigger sheets Ive seen have almost all been pretty well beaten up and damaged which makes it seem unlikely it will work for such a large cage. Are there any other good alternatives, or is there a way to piece together the corrugated plastic in a way to get the size I need and still have it be stable and water proof?

 

[Piggies&buns]

Pieces of correx can be tape together to make it big enough

 

[fluffysal]

I use these, got them from b&q.

 

[Guineapigfeet]

I used duck tape for my large corrogated plastic base. Worked very well and stood up to the task for 6+ years