How Long can I leave slab exposed

[Tin Soldier]

Hi there,

 

I'm setting about arranging trades to carry out the individual stages of my build after getting some frankly criminal quotes back from the local builders.

my question relates to the slabwork, foundation blockwork and drainage.

 

My build is schedule for April next year with the SIPS panel company coming onsite and erecting the house frame directly on preprepared blockwork/slab.

The slab itself is not the final finish with insulation, UFH and screed going on top once the kit is erected.

 

Can I build and leave the slab/blockwork this year, ready to go for April next year?

What are the risks of leaving it exposed?

 

 

[PeterW]

Hi

 

Very few risks, in fact concrete gets better over time ! You would need to ensure any below ground cavity is covered to stop any water ingress but other than that there is no issue. May make sense to leave a couple of places you can sweep out any standing water from the slab by leaving out a block or two.

[jamiehamy]

As Peter said, none really. But don't feel tempted to put any salt down if you are doing any work in a frost! Don't think that would react well! (we used to do work in winter with hard frosts. Bloody mad we were! We wore clip on things to stop us sliding). 

[ProDave]

No issues with the slab being exposed. I see it a lot here on small developments (probably building the slab so the development is "started" to lock in the PP then leave building the actual house until some time later)

 

Another point though, as you are having one contractor do the slab and another build and erect the frame.  Get the frame contractor to come and measure the site, check it for level and squareness, then build the frame to the actual on site measurements, NOT the measurements on a drawing.

[Tin Soldier]

ProDave

 

You've hit the nail on the head as to why I want the slab in early , in paid for and the kit manufacturer measures up

 

That's a great idea re the blockwork and leaving some gaps to sweep the water

 

Cheers Guys

[Nickfromwales]

I always wondered about where the water goes after rain hits the slab and goes down between the slab and DPM, which is essentially a pond liner. 

I just assume the DPM will likely have a tear in it or water would weep out of any overlapping joints ? 

[Declan52]

My slab was exposed for 18 months on my block build and caused no issues apart from the odd green bit of mould where there was a bit of standing water.

[ToughButterCup]

3 hours ago, Tin Soldier said:

[...]

Can I build and leave the slab/blockwork this year, ready to go for April next year?

What are the risks of leaving it exposed?

 

Compare the risk of doing it early next year with those related to doing it now. In terms of frost-free days, the consequences of getting the timing wrong are....