Does pcc layer must be isolated????

[HOMIeeee]

Hello engineers we all know that RCC footings must be isolated with not less than 2 layers of liquid bitumen but my question is the pcc 10cm layer under the rcc should be isolated or no ?

The engineers divided into 2 opinions

First opinion says that the bitumen weaks the texture between pcc and the rcc and the surface of the pcc must be roughed

Second opinion says the pcc must be isolated with bitumen and this doesn't decrease the texture between pcc and rcc and the pcc surface must be smoothed

What is the right thing between these 2 opinions

And actually I poured the pcc few days ago and the surface is roughed and i m confused do i isolate or not

Thank you and soory to prolong

 

[Ron]

If you coat the pcc blinding with bitumen it will create some level of isolation. It makes no difference whether you roughen the concrete surface, if you place bitumen on the blinding layer it will prevent bonding of the RCC footing to the blinding layer.

It is not necessary to bond the blinding layer to the RCC.