Replacement concrete floor

[martyy]

Hello,

I have a split concrete/ timber ground floor which is way past its sell by date circa 100 years

I am looking to replace the entire floor in concrete, now beneath the timber area I have 270mm from the Earth to the finished floor level (floor boards)

I do not really want top excavate any deeper in this area as the ground is extremely hard (using the thumb test makes no indentation in the said ground) so on that basis I was going to skip the type 1 go straight for 50mm sand blinding then the DPM/radon barrier 100m of celotex and fill to level with 120mm of concrete.

Can anyone see an issue?

Cheers

Martyy

 

[Deluks]

Can anyone see an issue?

Yeh, it's a lot of work, and concrete, and money. If it ain't broke, don't need to fix it.

But if you are itching to get stuck in...
Provided the GF joists are sound you will benefit from adding insulation between them. While you're there check that airbricks are adequate and clear of any crap.

The concrete floor can be dug up and replaced, to add insulation and a damp proof membrane. Maybe tackle that first and then see if you really want to concrete the entire house.

 

[martyy]

Can anyone see an issue?

Yeh, it's a lot of work, and concrete, and money. If it ain't broke, don't need to fix it.

Its broken

The concrete floor can be dug up and replaced, to add insulation and a damp proof membrane. Maybe tackle that first and then see if you really want to concrete the entire house.

We are in the process of an extension as well, so I was looking at doing the whole existing floor whilst there are no walls stairs etc.

I was just concerned at the omission of Type 1.

 

[Deluks]

No concrete oversite?

Your concrete floor doesn't need to be more than 100mm thick, insulation need only be 80mm celly/kspan, your blinding about 20mm, that leaves you some room for MOT. In any case wacker the existing and again after you've laid the stone (although stay away from the walls) and add some A142 throughout.

Have you allowed for screed or other floor finish?

 

[urbanite]

Consider putting the concrete down at the bottom, DPM/barrier over this and building up in EPS70, (that's a strength of EPS not thickness), 22mm P5 chipboard flooring.

Or look at Jabcore, which is an EPS that replaces the hardcore, although it does not protect from clay heave. Do you suffer from clay heave in your area? You lay your 100mm slab over this with the DPM between.

I don't know how anyone can say what thickness insulation you need without knowing your floor dimensions. It is worked out using the Perimeter/Area, go to an insulation site and look for the P/A value that gives you a u-value of 0.2 or better.

Happy building.

Oh dear.. this was posted a while ago. i think i may need thicker glasses,