How can I repair floor plate warped from hot dip galvanising?

[reddahaydn]

Hi,
We have has some stairs come back from the galvaniser with significant warping in the landing floor plate.
Is there any way to try and flatten these waves out to make it a bit less noticable?
Cheers

 

[Tmoose]

Wow.

Are the waves showing us that there are joists running crosswise?

 

[REGRUMBLE]

We have had this happen to us. You can add stiffeners in opposite direction if the customer will let you. Are you responsible for the design or just fabrication. Platforms and landings that are designed for galvanizing have a lot more braces than ones that are designed for painting. The designer should know better.

 

[moltenmetal]

Doubt you can "fix" that- rather, you need to prevent it next time with better design.

We always galvanize plates like that loose from their structures, then attach with countersunk fasteners. Others may have more economical suggestions.

 

[reddahaydn]

We are responsible for the design, however we are also the architect and PM so we end up dealing with this stuff as well.

In hindsight we should have specified that the floor plate was galvanised separately and not quenched, then attached later (either welded or bolted).
However shouldn't this be the fabricators responsibility? They are the so called 'experts'. There are plenty of stairs that have been galvanised without warping.

The plate is only 1100 wide. There isn't actually joists running under all of the waves.

Next time we will add stiffeners in the other direction, or get them to galv the plate separately but this time we need to get it fixed.

 

[StoneCold]

A very patient guy might be able to create a jig and using a porable hydraulic jack, press the waves down. It is a big maybe. That might also crack the galvanized coating and then you are done.

Regards
StonCold