Is rust on shipping containers an issue for building

summereire

Hi, we have an old prefab which is essentially a shipping container in its dimensions, steel frame, connectors on corners, though the walls are not steel but insulated board with a metal covering.

We were thinking of using the frame as the basis of a new building but have noticed that it's rusty on the surface. Does this matter in an way? Are we good to just paint over it after some sanding, or do we need to get it all off, or is the presence of rust a warning sign that best not to use it?

We plan on having it there for the next few decades (but covered as we'll just be using the structure) so want to make sure it will last if we use it. Thanks

PROJECT K

grind the rust off, prime it and use a suitable anti-corrosive paint and it should be ok - depends a lot on how you intend to upgrade to a "building" - will it be heated/insulated/ventilated/occupied etc etc. Shipping containers have been widely used as dwellings/offices etc but you need to be careful to introduce sufficient ventilation, ensure a continuous lapped and sealed vapour control layer on the warm side of the insulation (with no penetrations - i.e. provide a service cavity or have services only on internal walls).

summereire

Great thanks. When you say grind the rust off, is the aim to get it down to metal with no sign of rust or is it enough that there is nothing loose? The flat bits wouldn't be too bad to do but there are some lipped bits that are a bit more fiddly. Also have no access to underneath, could it spread from there?

PROJECT K

its important to get rid of all loose bits, after that it depends on what primer/paint you use - some can be used over a small bit of rust but its always better to remove as much as you can.

Markcheese

A good rub of a wire brush - then a big tin of hammerite and a few brushes that you don't mind binning - or you could use oxide paint (probably cheaper)

summereire

Thanks that's great. In practice does the bottom of the container matter much? Near impossible to get at without a crane and the edges are embedded into the ground, does the rust rise up from there, any clever strategies?