screed before walls and roof are up

[marmic]

Morning all,

 

opinions and experience please on type / thickness of screed.....?

 

beam and block; DPM wrapped up and over perimeter supporting walls sealed to DPC; 150-175mm PIR in 2 layers staggered joints and taped + upstands; membrane; UFH pipes; floating screed

 

current intent is 150mm PIR + 75mm reinforced floating screed (type / spec tbc)

 

Screed will be laid before walls and roof are on - timber frame company also building internal non load bearing stud walls straight onto screed. Reduces risk and grief!  Continuous build with no option to down tools for a week or two whilst a screed goes in after roof on.

 

Confusion and lack of trust now klcking in - screed companies quite excitable about liquid screeds and keeping to a minimum thickness and increasing insulation - which is fine. However, I'm now losing confidence as it seems the ones I had narrowed down to simply didn't listen with regard to the fact this would be open to the elements.  Appreciate can't do any of the options in rain, but moving air (wind) and sunlight is unavaoidable!  One has now suggested I put up a temporary roof which is bonkers!  Sounding like I may need to revert to original intent?  Which would be a shame as liquid screeds sound very good and also less cost!

 

guessing I'm not the first person with this conundrum!

 

 

 

 

[JohnMo]

Just do concrete, not screed. No effect once cured with weather. Just do fibre reinforced if you need anything.

 

We concrete with fibre 100mm thick.

[nod]

Most screeding  companies insist on the windows being in No chance without a roof 

[marmic]

1 hour ago, JohnMo said:

Just do concrete, not screed. No effect once cured with weather. Just do fibre reinforced if you need anything.

 

We concrete with fibre 100mm thick.

thank you - 75mm with fibre? just sand i assume to get around pipes?

[JohnMo]

9 minutes ago, marmic said:

thank you - 75mm with fibre? 

Yep

9 minutes ago, marmic said:

 just sand i assume to get around pipes

No, like this, insulation (PIR) polythene barrier sheet, UFH pipes clipped to insulation through polythene, then 75mm of concrete. Power float smooth.

 

Just like this

 

[marmic]

40 minutes ago, nod said:

Most screeding  companies insist on the windows being in No chance without a roof 

maybe none of them listened then!  frustrating as original intent was no screed with insulated precast 'slabs' ready for self leveller, but had to change as manufacturer moved the goalposts. But too late then to change the timber frame!

[marmic]

3 minutes ago, JohnMo said:

Yep

No, like this, insulation (PIR) polythene barrier sheet, UFH pipes clipped to insulation through polythene, then 75mm of concrete. Power float smooth.

 

Just like this

 

thanks John.........

 

[nod]

1 hour ago, JohnMo said:

Yep

No, like this, insulation (PIR) polythene barrier sheet, UFH pipes clipped to insulation through polythene, then 75mm of concrete. Power float smooth.

 

Just like this

 

 

1 hour ago, marmic said:

maybe none of them listened then!  frustrating as original intent was no screed with insulated precast 'slabs' ready for self leveller, but had to change as manufacturer moved the goalposts. But too late then to change the timber frame!

That picture isn’t a screed I think your getting a bit confused 

[marmic]

18 minutes ago, nod said:

 

That picture isn’t a screed I think your getting a bit confused 

no confusion!  pls see earlier responses / comments!

[JohnMo]

1 hour ago, nod said:

 

That picture isn’t a screed I think your getting a bit confused 

I wanted as the OP to do the screed before walls, so just used a normal concrete, it really doesn't care about the weather. For clarity we have zero screed, just concrete over the UFH pipes.

 

My build-up is

200mm rebar concrete slab, then 200mm PIR, then as described further up thread.

Edited yesterday at 13:46 by JohnMo

[marmic]

spoken to a couple of companies again -  as assumed they clearly hadn't listened previously!  People have been the biggest headache from day one on so many things - something i didnt anticipate going into this!!!   One is now proposing fibre reinforced flowing concrete 75mm thick which is almost as original intent!  (and I can't go any thicker). Waiting for call back from the other 

 

thanks all for comments - glad it wasnt me going mad!!

[JohnMo]

I just got my ground contractor to do it. Normal concrete lorry and in our case, but because of distance and access, we use a concrete pumping lorry also.