Veranda movement & reactive soil...

Wilson63 · Jul 28, 2016 1:34 pm

About 9 years ago, we had a Veranda built across the entire front of the house by a very reputable S.A. company costing nearly 15K. They have done work for us & our friends which has always been impeccable. Unfortunately, our soil is extremely reactive & over the years, the structure has warped, risen & sank at various points mainly due to the fact that the post holes were not dug deep enough and/or insufficient concrete was used to hold the posts securely. The company has been out several times & acknowledged that very same issue. Our problem is the company strongly advertises a 20 year 'structural guarantee', and whilst the veranda is still structurally sound, the movement causes water to pool, a gate not to open, etc.
Can someone explain the definition of 'structural guarantee' & whether we have any options/likelihood of getting the matter resolved e.g. repaired to cope with the type of soil on which it was built.

Thanks

B STAR · Jul 28, 2016 3:32 pm

I am failing to understand how and why the pergola can move that much. Is it possible there is an underlying drainage issues.

Wilson63 · Jul 28, 2016 4:57 pm

As I said, the people who built the veranda have agreed that the holes were not dug deep enough (allowing for such reactive clay soil) to fully support the structure. As an example, when we had a recreation/TV room built at the rear of the house, we had to pay an extra 10K for foundation reinforcement due to the movement of the soil. With the type of soil in our area, drainage will always be an issue due to the high concentration of clay. I was wondering whether this should have been taken into consideration when the veranda was built (as was the rec. room) & does this initial installation error fall under 'structural guarantee' ? It has more than sufficient guttering & downpipes

B STAR · Jul 28, 2016 7:21 pm

Wilson63

As I said, the people who built the veranda have agreed that the holes were not dug deep enough (allowing for such reactive clay soil) to fully support the structure. As an example, when we had a recreation/TV room built at the rear of the house, we had to pay an extra 10K for foundation reinforcement due to the movement of the soil. With the type of soil in our area, drainage will always be an issue due to the high concentration of clay. I was wondering whether this should have been taken into consideration when the veranda was built (as was the rec. room) & does this initial installation error fall under 'structural guarantee' ? It has more than sufficient guttering & downpipes

To answer you question yes it should have been.

I think the problem is no that I think about it your veranda is much bigger and structurally complex in comparison to the simple 4 post and colorbond roof that I had imagined in my mind. Did you have a photo at all?

Also was a building permit issued? and who designed it? usually there are standards for these types of things. If the builder installed it as designed then really the engineer is responsible.

qebtel · Jul 29, 2016 1:13 pm

B STAR

Also was a building permit issued? and who designed it? usually there are standards for these types of things. If the builder installed it as designed then really the engineer is responsible.

Correct, but remember, an engineers design will only be as good as the accuracy of the soil report it relies on.

B STAR · Jul 29, 2016 1:53 pm

qebtel

B STAR

Also was a building permit issued? and who designed it? usually there are standards for these types of things. If the builder installed it as designed then really the engineer is responsible.

Correct, but remember, an engineers design will only be as good as the accuracy of the soil report it relies on.

Yes another type of engineering report

insider · Aug 03, 2016 9:51 pm

B STAR

qebtel

B STAR

Also was a building permit issued? and who designed it? usually there are standards for these types of things. If the builder installed it as designed then really the engineer is responsible.

Correct, but remember, an engineers design will only be as good as the accuracy of the soil report it relies on.

Yes another type of engineering report

Get a copy of the soil report/engineering and see if the structure complies.If it doesn't then you may be able to take the matter further.

qebtel · Aug 04, 2016 1:33 am

B STAR

qebtel

B STAR

Also was a building permit issued? and who designed it? usually there are standards for these types of things. If the builder installed it as designed then really the engineer is responsible.

Correct, but remember, an engineers design will only be as good as the accuracy of the soil report it relies on.

Yes another type of engineering report

Nope, soil testing is lab work - chemistry. Nothing to do with engineering per se.

building-expert · Aug 04, 2016 6:40 am

It seems your veranda sits on expansive layer of highly reactive clay that is subject of seasonal movement due to moisture changes. The tone of your post suggests that builder has admitted posts footings should have been drilled deeper into stable layer but it wasn't. Also your experience with TV room means high soil reactivity is no surprise.
Whoever prepared building permit plans should have designed for the soil conditions and the regulatory checking should have picked up it wasn't so.
If the builder is simply building to someone else's design and permit approved drawings and the drawings were followed then it cannot be builder's fault regardless of his structural warranty.
However if builder has not followed approved drawings (and this is more common than you think) or has not taken care of surface drainage then more than likely it's builder's fault.
Finally, owner too has maintenance obligations on highly reactive sites, so I would have expected that surface drainage is maintained, was that so?

StructuralBIMGuy · Aug 04, 2016 6:51 am

Wilson63

As an example, when we had a recreation/TV room built at the rear of the house, we had to pay an extra 10K for foundation reinforcement due to the movement of the soil.

You should have queried the $10k for TV room as well? Material concrete costs for a whole new house is less than $10K?
BTW I put down material SI Units & Quants on all my work ie..m2, kgs, m, etc,etc egs below

Wilson63

With the type of soil in our area, drainage will always be an issue due to the high concentration of clay. I was wondering whether this should have been taken into consideration when the veranda was built (as was the rec. room) & does this initial installation error fall under 'structural guarantee' ? It has more than sufficient guttering & downpipes

Short answer unfortunately not...The word structural is bandied around too much theses days to the point where clients have lost trust in its use ..Only structural + engineer can advise you & Certify whats exactly needed beforehand.. goodluck fighting it.