Whats the best way to install a level concrete subfloor?

[deefadog]

I had my kitchen leveled with that plasticized mix stuff around 2 years ago (and i am in Swansea). I got a firm that work for a carpet company to do it as they were coming to put down the lino.

Took one guy an hour, just mixed it poured it and rolled it with special mini roller.

I think he charged £80 for it, which i thought was well worth it

 

[^woody^]

Yes you can do this, but strike the shuttering as soon as you have tamped and leveled the floor, and then fill the gaps with some of the readimix kept by from the main pour.

Yes a little bit will fall in, but the bulk is leveled and it is easy to just trowel the new bit level - even if it means walking in it with the wellies

 

[keycare]

I had my kitchen leveled with that plasticized mix stuff around 2 years ago

would that be self levelling compound (bagged stuff)?

I just had a quote for free flowing screed supplied by a company juts down the road...£1900+vat for a 11m x 4.5m floor. Whoa, he warned me that it would be pricey but that's just silly.

 

[Shytalkz]

Christ, with a 75 thick screed, that's only 3.75m3; £512/m3+ VAT, can't see that, someone's on the make there, even allowing for slightly more involved prep work.

 

[deefadog]

Not sure as i was in work, but is was the pasticy type, it dry like a bluey grey colour. If you go to the carpet place next to halfords in the enetrprise zone and ask for there fitters numbers!

 

[noseall]

the only trouble with free flowing concrete is you tend to get aggregate settlement which leads to an uneven dispersion of the aggregate.

ok for light domestic use though i guess.

i use a tamp and a 4' level. piece of cake.

 

[keycare]

OK, here's an update...

I finally found a supplier of Self levelling concrete. Hanson Premix had a product called easyflow that sounded about right. I ordered 6m3 at a cost of £750. Std concrete was going to cost about £550, so I figured it was worth the extra.

I suspended 4x1 planks from the ceiling joists so that the bottom edge of the 4x1 would be the level of the concrete. That way I could see the level without having to remove any formwork.

After a bit of mucking me about with delivery times it finally arrived in 2 trucks on Friday afternoon. (2 trucks because the wettness of the mix meant that if they filled up a truck it would slosh out of the back when going up hill.

It needed a bit of raking around but nowhere near as much effort as concrete. Me & My dad easily managed to spread nearly 50m2 of the stuff.

I made up an H-bar with 22mm copper pipe and end-feed joints to create a 'dapple-bar' to encouage the aggregate to settle just below the surface. Two passes at 90deg and I now have a really flat surface to lay my insulation slabs. I would be estatic apart from the fact that I miscalculated by about 1/4m3. I shuttered off a small section of the floor (so that the level was maintained in the rest of the floor) and will have to mix up about 3-4 loads to fill the hole.

The driver also gave me the number of a screeding specialist in Ammanford who does liquid screed. Hope it's cheaper than the £1900 I got quoted last month!!

TTFN.

 

[diyisfree]

Am i missing something here ?

cant say i have ever renovated an old barn before but i have laid my fair share of crete. Why didnt you lay sand binding, DPM, then insulation and finaly flood with the grey stuff ?

Ive only ever done it the other way when a radion mebrane was required and a raft foundation with ring beams for the interior walls.

Here's one i did the way you are because of radion barrier and raft.

Was knackered after floating all that lot so i forgot to take one after it had been power floated. Took 52m3. By the way, vibrating poker helps with leveling a little. My wife loves helping me with that

 

[keycare]

my ufh spec stated that the pipes had to be clipped to the insulation hence...dig out, sand + wacker plate, DPM, concrete...then insulation, etc.

I wanted a smooth flat surface to lay the insulation slabs on. Also, there was no way I could shutter-off the slab so tamping level would have been a challenge. I'm a DIY'er so not the level of experience with concrete that you pros have.

 

[diyisfree]

Ah,

Sorry. I didnt read the bit about underfloor heating You going for a wet system then ?

 

[Shytalkz]

Ah,

Sorry. I didnt read the bit about underfloor heating You going for a wet system then ?

Heheh, never mind it was nice to see your pix

 

[keycare]

Yes I have already installed and part commissioned a wet UFH system from Nu-heat in the other part of the house. I can recommend it as far as warmth and comfort is concerned and installation was a doddle.

 

[keycare]

BTW I'm really impressed by the surface finish of this easyflow stuff. It's almost "finished screed" quality.