Any recommendations for tanking this plant room?

[Great_scot_selfbuild]

We've a very airtight build (timber frame) and the plant room has a dry screed floor.

 

I want to tank the plant room so the if the DHW cylinder leaked / flooded, then the plant room could hold the 300 L long enough for me to pull the plug out of the drain (before laying the floor I installed a pipe that it could drain through); the floor of the house is suspended off the ground, so there's no issue with where the water then drains to btw.

 

The photo shows the plant room floor with the various ducting and airtight tape. I need the tanking area to be 150mm deep to hold 300L, and was going to batten off the bottom of the door area to create a step-over into the plant room.

 

What would you recommend for tanking the plant room floor and up the sides of the walls to the 150mm height?

 

Any other comments / advice welcome (is this overkill? I'm perhaps being over-precautious about having a timber framed house and not wanting to risk anything significant).

 

TIA

 

[JohnMo]

51 minutes ago, Great_scot_selfbuild said:

create a step-over into the plant room.

Nice trip hazard!

 

If you need to it in the plant room, do you need to do it to every wet room, a fitting may leak while you out for the day?

 

Do you have a floor drain? That maybe all you need. If not your hot swimming area will be difficult to empty anyway.

 

Maybe over thinking it, our cylinder is above the kitchen, is it bunded area no, have I had leaks yes, were they an issue, no.

 

 

[Great_scot_selfbuild]

1 hour ago, JohnMo said:

Do you have a floor drain?

Yes (mentioned in first post) - there's a drain, but it will be plugged to retain the airtightness.

 

Valid point about any connection could spring a leak, but only one room has a tank ready-filled with 300L. Good to hear I'm over-thinking it, but a sodden ground floor with timber walls was my worry.

[Russdl]

3 hours ago, Great_scot_selfbuild said:

if the DHW cylinder leaked / flooded, then the plant room could hold the 300 L long enough for me to pull the plug out of the drain

If you were home. 
 

If the DHW cylinder sprung a leak why would it only loose 300L, wouldn’t the supply of water be endless until you isolated it?

 

I reckon you are massively over thinking this, get a flood sensor (Shelly do one, I’m sure many others exist)

 

If you spring a leak, unless it is some kind of catastrophic failure, then it’ll take a long time to empty that tank.
 

A flood sensor will tell you the floor is getting wet whilst you’re miles away, you send the neighbours round to isolate the leaking component and continue your holiday. Small leak, dries relatively quickly, zero damage to the timber frame but the plasterboard may need some attention. 
 

[crispy_wafer]

Would it still need to be plugged if there is a water seal in the drain trap?

[dpmiller]

^ or even better a waterless trap

[Russell griffiths]

Use a waterless trap then you don’t need to be home. 
im as crazy as you, see pic.