ICF Prep for services

[Adam2]

Am about to pour our first floor. It's a semi basement with no drainage so just thinking about providing electricity for exterior lights and a power run down to the garden. Don't want to drill through 200mm of concrete so thinking to put 3 steel conduits about 10mm dia through the walls now. 1 each for 2 external wall lights and 1 for power to garden. Is this best or should I do 1 conduit maybe 20mm and install conduit in the external eps ?

[Alexphd1]

No big issue drilling holes in 200mm concrete (with the right tool) . I would be installing individual conduit to each point, I dont like the idea of running conduit in the external eps. 

[willbish]

I've gone for the drill through after approach.

 

Hasn't been too much bother. 20mm plastic conduit inserted and 100mm square section of EPS removed on the inside to be able to form airtight seal between hole and conduit

[Russell griffiths]

I’ve drilled after the pour, 25mm hole, 20mm conduit, air sealed with illbruck air sealing gunge. 

[PeterW]

Always drill after. Conduit cast in during a point can get bent or moved and then you need to re-drill anyway. The other issue is always light placement - until you know what the outside looks like, you may want to move the outside lights about so that is much easier to do if you haven’t been constrained by conduits already installed. 
 

32mm dry core diamond bits aren’t expensive for what you get and can be used with an ordinary SDS drill.  That is more than adequate to get most services into a house and can be sleeved with waste pipe and sealed without too much issue. 20mm conduit ideally needs a 22mm SDS bit but is easily drilled with a standard bit. 

[Adam2]

Awesome good reasons to not commit to early decisions ?