basement bathroom and utility room floor insulation

My basement is big (1600sqft). It is open space and bare to concrete wall and floor now. we have a bathroom there and plan to have a utility room as well. The gas boiler and hot water tank are in that area already. I added French drain around the wall and a sump pump last winter in case the 500yr flooding comes earlier. I have put two floor drains (one in bathroom and one in utility area) and three cleanouts with the French drain system to make sure water will have a good place to go if any.

I will follow suggestions from experts here to finish the basement. For the floor, i have a bathroom and a planned utility room, and also have floor drains and cleanouts on the floor. how should I handle them?

The floor will be insulated like this: 6mil ploy + 1" XPS foam board + 3/4 plywood.

1. utility room: I plan to have a separated utility room; seal poured concrete wall and floor with XYPEY. Because the pipes for air, water and gas have been there already, it is hard to do insulation in that portion. I lean to have no insulation on the wall and floor for that utility room.

2. bathroom: should I insulate the bathroom floor as other rooms?

3. floor drain and French drain cleanouts: should I make those floor drain and cleanouts available after the insulation? if yes, that means the insulation is nor sealed properly. If no, ...

What's your advice?

 

What is the purpose of the 6mil?

 

vapor barrier, I think.

 

With an inch of XPS on the floor and a sealed slab the 6 mil poly isn't essential, but it doesn't hurt.

DO make the drains & cleanouts accessible. The exposed surface area that would be exposing (and then not vapor sealed) is very small and of no consequence. Concentrate on air-sealing- infiltration from the outside is a far larger source of moisture than a few square feet of exposure to sumps & drains.