Construction tolerances

Member for

19 years 10 months

Hi Gary

It has to be calculated - Bottom up 5mm Mid up 5mm Top down 5mm should do it.

Best regards

Mike T. 

Member for

15 years 9 months

Dear Mike,

 

My problem is if for example there are totally 3 layers each allow +/- 5mm tolerance, the bottom is actual +5mm higher, the middle layer is also +5mm higher, while the top layer is also +5mm higher , it comes out total +15mm higher, but the specification say the finished road level should be +/- 10mm only.

 

Do the contractor have any grant to say that the specification does not allow accumulative tolerance and who should bear the responsibility?

 

 

Regards,

 

Gary Lo

Member for

19 years 10 months

Hi Gary

A prudent contractor works to the tolerances to achieve economies.

For example a tarmac road will be in 3 layers Base - Bearing and Wearing.

The lower courses are cheaper than the higher ones. If the tolerence for each layer is + - 10mm the the cheaper layers are increased and the upper layers decreased still achieving the finish level.

Best regards

Mike T.