Question on piers

Vlad76 · Jun 10, 2007 1:47 am

I just had my piers put in prior to the slab, due to soil being classified Class P. These things are hard to check, whether they've been done properly or not, in terms of depth or even number of piers going in, as you just can't see them once they have been put in.

Supervisor told me he'd get an independent report on that to confirm they've been done as per engineers specs.

But what I did notice, a few holes in the ground towards the back of the block. Not sure what they were, but it could have been piers going too deep, or them drilling in a wrong place and leaving the holes empty.

Has anyone who had piers installed seen anything similar?

Casa2 · Jun 10, 2007 2:15 am

Vlad,

I know about as much as you, but I would have thought that if your piers have been build you should at least be able to see how many there are? :shock:

Cheers,
Casa

Hennig · Jun 10, 2007 10:23 pm

Mate, in Victoria, the building inspector has to inspect the pier holes prior to filling them.
Get a copy of your slab design from your builder, if you ask politely he may give you one, if not use the privacy act - never fails.

Vlad76 · Jun 11, 2007 2:48 pm

I have the plan of the piers design.
The problem is once they're in, you can't see them as they are below ground level. In some cases I can see concrete traces on top of where the pier has gone in, but in some areas it's covered with soil.

There is no reason to suggest they haven't been done properly, but what worried me a little was that I saw a couple of holes in the ground towards the back of the block, which suggested to me that either they were holes drilled in the wrong spot and abandoned, or piers that went too deep if that makes sense.

I will ask the supervisor on Tuesday, and will ask for the independent report copy.

I am 99% sure everything is fine, but you can't help but worry a little given these things aren't easy to check yet mean a helluva lot to the future and longevity of the house.

david s · Jun 11, 2007 3:55 pm

Hennig

Mate, in Victoria, the building inspector has to inspect the pier holes prior to filling them

I'm in QLD and a class P requires design and certified by an Engineer.
My engineer requires two inspections at this stage:

1) Foundation and excavation stage – before the footings are poured; and
2) Slab stage – at completion of reinforcement installation but before to
placement of concrete;

Building certifier is also required to inspect at the same time too.

I've got non-reactive soil but part of the slab will be built over soft soil where a mango tree used to be. I'm still not sure if the piers are going all around or just in the soft part as we need to excavate part of the block 1 meter and the soil test shows good soil at 700mm on this side.

ahuang · Jun 14, 2007 12:48 am

Hi Vlad76,

Why don't you take a few photos? In case you need to prove it to someone for whatever purpose in the future.

In my contract, the builder actually specified how many meter of pier length are covered, anything over that is charged something like $75 per meter. And we were told we will be asked to come on site to check when they drill the hole, just to prove they don't over charge us. Do you have anything mentioned about the pier in your contract?

Cheers
Allan
http://building-our-first-house.blogspot.com/

Vlad76 · Jun 14, 2007 10:27 am

The pier details are not in the contract. But they are very well described on the engineering report which includes some nice digrams.

3timesbuilda · Jun 14, 2007 11:56 am

When we had piers, they put in a provisional $ amount. When they put in the piers, they found that the ground was better than the soil test indicated so they did not put in as many piers as originally planned. Ie. they responded to the conditions as they went.

We got some $$$'s back since we didn't need as many.

Perhaps they decieded that the extra piers are not necessary or perhaps they were test holes?

3xb

ahuang · Jun 14, 2007 1:28 pm

Vlad76

The pier details are not in the contract. But they are very well described on the engineering report which includes some nice digrams.

Engineering report? How come I didn't receive anything like that from AllCastle? We did have a engineering drawing for the retaining wall but that's for landscaping.

I only received a final drawing marked as "construction set", a list of colour selection/upgrades, drawings for electricity stuff, and a tender.
Or is it because we haven't sign the contract yet??

Our slab is class "M", are we suppose to receive a "Engineering report"?

Cheers
Allan
http://building-our-first-house.blogspot.com/

Vlad76 · Jun 14, 2007 2:04 pm

I'd say you should ask for one.
I got mine at the final stage when I knocked down the old house on the block and they did a final soil test and contract consolidation.

I then requested the engineering report which included all the slab design, piers, retaining wall, roof and things like that.

david s · Jun 14, 2007 11:28 pm

ahuang

Our slab is class "M", are we suppose to receive a "Engineering report"?

Mild reactivity.

IIRC doesn't require engineered slab, like P for Problem.

burnettcastle · Apr 09, 2009 5:38 pm

We will have a lot of piers due to a 'p' class of our block

Should I also get a inspector just to check the piers before the slab is poured? I am worry not as they will pour the slab next Thursday and I am running out of time.....is it really important to have the piers checked before the slab is poured?