Piers\Footing poured at same time as slab?

building-expert · Sep 04, 2015 7:43 pm

We just completed bored piers for my extension and sure enough when we bored them out we had some water seepage. We cleaned them out , had them inspected and poured concrete. I would have hated to have them open for couple of days with seepage and sides falling in, and what if it rained?

building-expert · Sep 05, 2015 10:23 am

Guess what?
It's raining, boy am I glad I poured concrete yesterday.

goody59 · Sep 06, 2015 10:35 am

It is the way it should be BE.

mgilla · Sep 06, 2015 8:25 pm

insider

The piers are in contact with the soil and moisture could travel up the pier onto the slab.Defeats the purpose of a moisture barrier but I'm guessing because I haven't seen it done before.

Its no different then when internal beams are poured first and the plastic is only put over the pad. The beam is left exposed with starters that are then tied into the slab mesh.
There seems to be a perception on H1 that just because someone has never seen something done a certain way then it must be wrong.

building-expert · Sep 07, 2015 7:34 pm

mgilla

insider

There seems to be a perception on H1 that just because someone has never seen something done a certain way then it must be wrong.

I don't think its wrong and it is good to experiment. In any case forum is for the exchange of ideas.
I just don't like the risk of leaving open excavations overnight but there may be a s special case where it is convenient or necessary.
It depends on many factors and including cost effectiveness of a particular method.

insider · Sep 07, 2015 8:55 pm

mgilla

insider

The piers are in contact with the soil and moisture could travel up the pier onto the slab.Defeats the purpose of a moisture barrier but I'm guessing because I haven't seen it done before.

Its no different then when internal beams are poured first and the plastic is only put over the pad. The beam is left exposed with starters that are then tied into the slab mesh.
There seems to be a perception on H1 that just because someone has never seen something done a certain way then it must be wrong.

Not saying it is wrong just interested how it would work .I haven't seen internal beam done that way either.I suppose it is the engineers I work with have their particular way of doing things and that's what you get used to.

simrob · Jul 14, 2016 12:24 pm

Gday all,

Im currently having some issues with whether or not i have had my piers put in.
Reason being is i have been there every night and have not seen a hole, or the leftovers of any concrete to indicate they had been done. I just went last night and the waffle and re-bar was all done and the builder told me the piers are already done. Is it possible to have the site prepped, piers dug, checked, filled and the all the above slab all prepped for pour in one day? seemed way too fast. and its not a tiny slab, its a 46sq double and i was told it needed piers all through it.

Looking though this topic it seems that the holes have to be checked by an external body. Can someone tell me who that body is? council? I want to check for myself. should there be photos?

Cheers
Simo

building-expert · Jul 14, 2016 3:41 pm

Have look at your building permit then call your building surveyor and ask for pier inspection certificate.

insider · Jul 14, 2016 7:49 pm

The geotech or engineering company will inspect the piers to confirm they are founded into the appropriate material and companies like group 4 building surveyors also will inspect the piers.You can have the excavator cleaning holes while you are inspecting and the concrete pump and trucks lined up waiting for the go ahead so it can be done all on the same day.
If you have the design you can physically check if the piers were installed usually there will be a pier at least on every corner.

StructuralBIMGuy · Jul 15, 2016 8:37 am

simrob

Gday all,

Im currently having some issues with whether or not i have had my piers put in.
Reason being is i have been there every night and have not seen a hole, or the leftovers of any concrete to indicate they had been done. I just went last night and the waffle and re-bar was all done and the builder told me the piers are already done. Is it possible to have the site prepped, piers dug, checked, filled and the all the above slab all prepped for pour in one day? seemed way too fast. and its not a tiny slab, its a 46sq double and i was told it needed piers all through it.

The question is, was it done correctly and certified complaint? I doubt it because
With cement trucks backed up ready to pour.. dealing with non-compliance in this instance becomes a big problem.
All engineers require at Least 24 hrs notice prior the pour to check drawing & compliance matters, for this very reason

simrob

Looking though this topic it seems that the holes have to be checked by an external body. Can someone tell me who that body is? council? I want to check for myself. should there be photos?
Cheers
Simo

Here in WA an engineer should issue inspection and compliance certification and this is available to all clients when requested, you should have something similar please check with your local Council building authority

simrob · Jul 15, 2016 1:59 pm

Great, Cheers for the info all, will go follow it all up now

Steve G. · Nov 20, 2023 7:58 pm

1.) Edge and slab piers up to 0.4 m in depth may be poured integral with main slab.
2.) Edge and slab piers between 0.4 m and 1.0 m may be poured integral with main
slab providing a bond break is installed between top of pier and underside of edge beam.
3.) Edge and slab piers greater than 1.0 m must be poured separate to main slab.