best cheap paint for wooden floors

[AstonHill]

I have a 45 foot box trailer with wodden floor boards
Would like to paint them so they are looking nice and to protect from water damage in the future
Dont want to spend to much money on it though as it will never ever add value to it

any ideas on paints please?
Thanks

 

[Mottie]

Same as my other post. Used engine oil.

 

[AstonHill]

Same as my other post. Used engine oil.

And what do you know about painting then? same as plumbing I guess

 

[Mottie]

And what do you know about painting then? same as plumbing I guess

I know you don’t want to spend anything and will disregard just about anything anybody tells you. I'll humour you though, how much would you like/have you got to spend then? £10? £20? A dead hedgehog? An empty propane bottle?