Quality Control of the Slab's Concrete - The Report

After much requesting, the quality report of the slab's concrete (as detailed in this post - Quality Control of the Slab's Concrete) finally arrived!

My personal suspicions are that these reports are generated regularly within Boral, it was the fact that an end client was requesting a copy is what threw them.

I never got any sense that neither should i not be asking nor should I be receiving a copy, more of a how do we get that?

Frame overhang issues

I've seen a lot of posts on the forums about frame overhang, where the frame overhangs the slab by an amount, sometimes in excess of the building standards.

A lot of the owners are getting very upset by this.

We had one location where this happened to us (the front corner of the study).

A small amount of overhang.

I asked our independent inspector about it: "Should I be concerned?".

His answer was interesting, not quite what I expected, so I thought I'd share it here, hopefully to alleviate some stress and anxiety of owners.

Even if it is not to standard, even if it should proceed to VCAT/legal action, essentially what it boils down too, is this: will it functionally work?

Quite unexpectedly, pragmatism wins!

In the case above, I'd suggest that the overhang does not functionally impare the overall functional requirements of the frame. The inspector was not worried about it. No rectification was performed.

So hopefully, this real world example provides some information that helps ease any stress and anxiety that other owners many find themselves facing, should they experience a similar situation.

First days of framing!

True to form, the day after the first timber had been delivered, the framers started.

They did not muck around.

I spoke to the framer in charge. A young guy. He was happy to talk to us, for 5-10 minutes, but beyond that, he got itchy and wanted to get on with the job. He told us that we were one of the very few who actually got out of our cars and actually spoke to them. Most take pictures from their cars, some get out to take pictures and even fewer still talk to them. I was really surprised by this. They were even more surprised when we dropped off a carton of beers that night to them. "No one does that anymore!" They were happy enough to receive them, and personally, I don't think that it hurts to treat them as people.

I informed him that we'd be getting an independent inspector to review every stage of the build. His response was interesting: "I'm glad you told me. Now I have to do everything properly." (well, I've paraphrased his response to clean it up). Clearly he was not happy at the prospect of having his work critically examined. I asked the obvious question: "well, given the amount we are spending, shouldn't you be doing it right anyway?" That question went unanswered... He did whine a bit about "having to do it right" and that the inspectors "always pick up on bits that are not important" [to him at least]. Evidently he had a different opinion on the interpretation of the Australian Building Standards with respect to straps, tie downs and bracing. I'm glad that the independent inspector and our site supervisor sees things differently "code is code, and that's how it will be done".

10am 16th April 2015

10am 16th April 2015

8:45am 17th April 2015

10am 17th April 2015

It took them only an hour to add the frame for the dining room and alfresco!

By the end of the second day, even though it had rained, they had accomplished a lot.

4pm 17th April 2015

4pm 17th April 2015

4pm 17th April 2015

4pm 17th April 2015

4pm 17th April 2015

4pm 17th April 2015

Skipping ahead to the end of the frame stage, post frame inspection report: Yep. As expected, the issues that the framer whinged about were indeed what the inspector did pick up on. Our site supervisor made sure that they were rectified. I spoke to him about the issues that he was fixing. Whilst he was going to fix them, he did say "I was never taught this way of doing things...". Clearly the thought that he'd possibly been taught incorrectly had never crossed his mind. Although, I do wonder if it had been done deliberately, as an act of defiance.

Anyway, it is certainly not something that we have gotten stressed over. There is a good relationship between our site supervisor and our inspector, so I trust them to deliver what is needed. Our overall mandate to our site supervisor: we are not in a rush for this house, just do it right.

Quality Control of the Slab's Concrete

For those of you who have paid attention to the recent press about slab issues (particularly out west of Melbourne), you may, as I have, wondered about what, if any quality control was in place for the slab and it's concrete.

Our particular slab was thicker than normal. This particular thickness that I'm talking about is the thickness of the concrete above the waffle pod. Most are 85mm or 100mm. Ours was 125mm.

In addition, the comments from both our independent inspector and the guys who put it in place also said that it was a very heavily engineered slab. More so than usual. This was in relation to the amount, and gauge of mesh put in place.

The engineers who designed the slab, it's piering etc had their reasons for doing so. Who knows! I'm not an Mech/Civil Engineer. But both my brother (Mech Eng) and my father (Mech Eng and Metalurgist) are engineers...

All of that is fine, but the engineer would also have specified the strength of the concrete itself. It is specified in MPa (Mega Pascals). What if the concrete itself was not up to specification?

I was most surprised, and utterly thrilled to see that the concrete itself being tested.

How? They take samples, let them set, and the test them. Destructively. Which is the only way that it can be tested properly.

There was a man from Boral who was taking samples of the concrete, from each truck and making testing samples.

Ever seen a thermometer in concrete? Now you have.

Samples from each truck were taken and placed into these setting pots. They each had a base and split down the middle.

They were then vibrated to allow the concrete to settle and then get rid of all air bubbles etc.

All of the samples were gathered together, and would be allowed to fully cure for seven days before being destructively tested to verify the concrete strength.

I asked the man taking the samples, how you would fix the concrete if it was not up to strength. He smiled and simply said "With a jack hammer!". Which would be the only thing you could do, as there is nothing that you can do once it's set.

So, with all of this engineering and testing, I'm hopeful that the slab issues that have plagued the building industry of late have been put to rest.

NOTE: As a follow up, please read Frame Overhang Issues for a discussion about slab issues and how they can be resolved.

Another follow up NOTE: The quality report has been received! Please read Quality Control of the Slab's Concrete - The Report for details.