It is always a question of the level of durability, but a surface produced with Controlled Permeability Formwork is very durable, and certainly competitive to silane and other surface treatments. Furthermore, CPF improves the actual concrete instead of taking measures to improve poor concrete...
We are the producers of a Controlled Permeability Formwork (CPF) liner called Formtex.
You do not write what brand of CPF has been used, but generally concrete produced with CPF is very durable and does not need silane treatment or coatings of any sort. What the CPF liner does is to drain out...
There is an alternative to Zemdrain. Fibertex in Denmark produces a liner Called Formtex (see www.formtex.dk). This liner is just as good as zemdrain but 30 % cheaper!
