Lintel bowing

Just currently in discussions with my builder regarding the bowing of a lintel above our 3600mm stacker door in the alfresco area. The builder has used a 6mm lintel instead of a 10mm lintel (150 x 100 x 10 as per engineering plans), which has now created the bowing. Build is finished, and we are in maintenance period at present.

The builder's engineer has come back and advised;

"the maximum 6mm deflection above the rear 3.60 metres wide slide door does not undermine the structural integrity of the angle.
The maximum allowable deflection is determined as span divided by 500 which is approximately 7-8.0mm."

I'm of the belief that the deflection is at least 9mm.
Is anyone able to advise whether the engineer allowable deflection statement meets tolerances under the standards? I am having difficulty locating this tolerance allowance.

Thanks for any assistance.

You don't need tolerance. If the builder has failed to install 10mm lintel as specified its a breach of contract and a breach of warranties.

Thanks. That's my stance as well.
I just wanted to know if their tolerance argument (the calculation) was valid, if they had used the correct 10mm lintel.

ozmonkeyoy
Please put up more info, and photos (which also helps others) and you will get the info & proofs you require
OT, you put heaps of pretty snaps up during your build ...but i noticed you missed a lot of important Structural Stages.Not all mistakes are easily picked up once the house is finished often they are buried, concreted and covered over. Over the long term your bricks will crack over those lintels.. ..was the Brickwork Reinforced
I also noticed your house is a double storey that makes it worse?...

Thanks.
Will post a few pics when I get a chance.
Didn't post a lot of the structural work on the forum during construction, but I do have a lot of those pics on file.
Oz

That is of major concern
How are those structural photos on file going to help you when issues manifesting outside of the warranty /structural period present... when you didn't bring them to the builders attention before hand?

Works were inspected throughout build by various parties, any known defects/issues were brought to the attention of the builder during construction, and seemingly rectified in our eyes. Photos show no major structural issues, although there may be issues beyond my scope of knowledge. My position involves working with a few building clients and throughout the house build process they were asked many questions and showed different stages of the build, without many concerns raised. Building inspector was engaged during construction, issues found and those rectified by builder.

This particular lintel issue was not picked up. The bowing effect really pronounced only after handover, not so much during construction. My eyes did not see that the lintel thickness was different to all others - kicking myself that I didn't see it sooner. Photos directly related to the lintel in question are scarce, as I away at the time that those works were happening.

I couldn't really have been much more proactive during the build than I was - for the average homeowner, we are time poor and have limited knowledge of the process. Contracts and warranties ensure a level of protection, outside of this (as with most things in life) there's probably not a lot protection for consumers.

Odd attitude to have? It’s not the consumers responsibility to identify and rectify issues. Building with a volume builder you can’t even go on site without the site supervisor present, it’s very difficult to see each stage in detail let alone project manage it.

ozmonkeyoy
Ok I get it, you ask for assistance and in addition you don't like what you read.
Here are my further comments
1. Put a claim on your Builders Inspectors PI Insurance company for major Structural Repairs or
2.Take action against your builder as I can't see how it's the Engineers fault as I doubt he inspected it
3. The long term lintel bowing will get worse and it results from Metal Stress/Creep.. engineering calculations are available
Photos help, always put a tape measure in for dimension & reference purposes
4. Lintels are mostly visible, my comments refer to other items that are not visible. This also begs the Question "If They missed visible Lintels ..what else has been missed during inspections?"
5.Being Kicked doesn't help, but I've always found honesty to be the best approach
6.Unfortunately the current system is not geared to help the average Battler & Punter Homeowner,Hopefully the New Engineers Act 2018-> will make Building Practitioners accountable but that's another story
7.A sympathetic response is not going to solve consumer building problems.. you need to take action when required
Finally, I read odd attitude to have, That's the general attitude I have on site when i inspect Structural Problems/Repairs out of warranty that involve costly repairs compare my attitude to the swearing, crying, anger i hear from owners...I believe my attitude is acceptable. Basically they get mad but not at me hth

BTW how many times did you visit your building site during your build...just curious?