Weep holes in DPC for cavity - Full fill, flood zone

[boxrick]

I am building an extension and renovating my home. I am in a flood zone and my builder is asking me about the cavity on the extension saying he normally installs weep holes through the DPC layer and wanted my thoughts on this due to flood risks. 

I am wondering can we skip them entirely or is it best to use something like this? I believe we need over 50 for my build

https://www.m3floodtec.com/shop/products/one-way-weep-vent-m3whvw

I am also installing EWI everywhere

 

Edited Thursday at 08:24 by boxrick

[Mr Punter]

Just have normal weeps above the cavity trays over lintels.  I don't know why you need them at low level.

[boxrick]

20 hours ago, Mr Punter said:

Just have normal weeps above the cavity trays over lintels.  I don't know why you need them at low level.

Wouldn't you need them at both levels?

I am thinking of skipping near DPC for now and just retrofitting the flood ones if it turns into an issue, but still not entirely sure of this decision.

 

[Mr Punter]

Any water in the cavity low down will go down to the foundations and drain away.