Building on Boundary Problem

Hi Guys - I need some advice...

Building with a major builder, and ready for slab stage to take place, i just received the bad news that our job has "stopped" due to what seems to be an error made by the engineer.

We have chosen to build our home with our garage set on the boundary. As it turns out "on the week the slab was due to be poured" our builder picked up that our next door neighbour (who's garage is also lined against the same boundary) has a slab thickness of 300mm.

Because our engineers report recommended that we use a 600mm slab thickness we are unable to proceed because if we do with the 600mm slab, we run the risk of causing damage to the next doors home (from what I understand it has to do with the weight of our slab vs theirs).

I'm no builder but shouldn't this have been picked up by the enigneer conducting the Footing Report Recommendations?

The way forward is for next door to agree to have their garage underpinned, to allow further strength. If they accept this, we may be forced to cough up more cash to rectify - and this is after contracts have been signed off on . I know there are provisions for finding rocks etc, but to me a builder's stuffup (it's their engineer who submitted an non detailed report) should be covered by themselves.

Is this a common issue?
Should an engineers report cover such information (slab thickness of next door home)?
Surely they builder is responsible for letting this slip??? [/b]

Havent heard of anything like this, but it does prove that people are paying attention to your plans, which can only be good.

Anyone else help?

Hmm - Interesting issue.
I'd say the builder has to foot the bill, their mistake - their cost?
That's what I do with my projects
Maybe go halves is an option - 1/2 builder 1/2 you - but don't cave in too early and be hardnosed talking tribunals etc first.
Steve

If this issue was detected earlier you would still have had to foot the bill to protect your neighbours slab.

Unfortunately I think you'll find you will have to pay for this.

Get some more information on the reason first.

I don't see how the weight of your slab can affect the neighbours slab.

The only thing I can think of is that, because your edge beams are 600mm thick, the builder has to excavate below the edge of the neighbours 300mm slab, which may cause it to crack.

Couldn't they shore it up during construction? After your slab is down, there is no problem as far as I can see.

Or could the engineer design a beam 300mm deep but wider, so it has the same strength as the 600mm beam?

Was the neighbours garage there at the time of the engineers initial inspection? It should have been shown on the DA approved plans if it existed before, so the engineer would have known about it.

Thats probably what they are planning to do. Temporary re-inforcement of the neighbours slab.

Thats the extra work that will need to be paid for.



Perhaps they didn't know the thickness of the neighbours slab until they started excavating. They may have assumed it was 600mm thick and didn't foresee any problems.

Thanks for the feedback.



Thanks for the tip. It's still early stages and there is no confirmation that we will be fed the cost, but I won't be caving in.



Check, and will get more info from builde. Neighbours garage was there at the time of engineers inspection, and was also included on the DA Approved plans - I specifically recall our admin officer advising there would be an engineer requiring access onto our block to check the depth of next door's footings. So it looks as though someone didn't do their job...


According to our contract we have paid approx $200 for a footing probe to take place. Of course there was also a note stating if any costs arising from the investigation were found that they will be charged to us via a Post Contract Variation.

This was then followed up by a Post Contract Variation confirming there would be no further costs assoc with this as per footing probe report.

The way I look at it is we have been quoted a price which has been agreed on. In this price I can only trust the builder has done their job properly and has quoted accurately - we shook hands (signed off) and the deal had been sealed. There is no mention of incompetence by builder will result in extra cost to client.

I'll have to wait and see with what they come back with - there's no point worrying about something I can't control. I wonder what our options are if the neighbour declines builders request!!!

Different….I’ve not heard this one before.

Strange how you are expected to foot the bill for something on the next block.
Doesn’t seem right to me.

That would be my main concern. Hopefully the neighbours are accomodating. You might have to buy them a slab.

Still doesn’t seem right!
What’s going on here?

Stewie's slab is going to butt right up next to the neighbours existing slab. Both slabs go right to the boundary. However Stewies slab needs to be 600mm thick. The neighbours slab is only 300mm thick. They need to dig down 600mm on stewies side which may weaken and possible crack the neighbours slab. Therefore the neighbours slab needs to be reinforced until Stewies slab is set and dry.

They need to ensure they don't do any damage to the neighbours house whilst building Stewies house.

Thanks Mark….got all that, but are they both building at the same time?

Nope. From what I can gather neighbour is existing house.

That's right CookieMonster.

OK…….now I see the problem!

Yes a bit of a worry! Good luck with your resolve Stewie!!!!

Stewie from what you've said you won't be paying anything.
The only problem associated with the edge beams is stopping the soil under the neighbours beam from moving. This is generally not a big deal but does take a bit of time to set up boxing etc.

Cheers Ausdesign for your professional opinion...it's much appreciated and a relief to hear that the problem will not automatically result in extra cost.

I guess I'll have to sit back and wait to hear from the builder to see which direction we head. I'm sure they're doing their best to hurry the process along - after all, the longer they take, the longer it'll take for them to see the $$$.

Stewie