Extension floor slab

[e39boy]

Hi everyone

I am going to prepare and lay the concrete floor to my extension myself.

I will need to run a pipe under the floor to provide ventilation to the existing suspended floor.

I have already laid down hardcore and sand.

I wanted to do the concrete slab first and then the insulation, followed by screed.

Before i pour the concrete slab, do i need to put down a membrane first)

 

[23vc]

Yep, I would. Particularly as you’ve put sand down.

 

[noseall]

I will need to run a pipe under the floor to provide ventilation to the existing suspended floor.

You seemed to have jumped the gun a bit there. Presumably, that lintel (with the dodgy remaining end bearing) is where you intend running the duct?

You should have run the pipe lower (beneath or in the hard core layer) and terminated with a telescopic vent, via proprietary reducing fittings and an air brick etc....

tele1.jpg

• noseall
• 18 Jan 2025

uvent1.jpg

• noseall
• 31 Aug 2024

uvent3.jpg

• noseall
• 31 Aug 2024

 

[noseall]

Hi everyone

I am going to prepare and lay the concrete floor to my extension myself.

I will need to run a pipe under the floor to provide ventilation to the existing suspended floor.

I have already laid down hardcore and sand.

I wanted to do the concrete slab first and then the insulation, followed by screed.

Before i pour the concrete slab, do i need to put down a membrane first)

The best you can do now is lay the polythene and surround the pipe with concrete.