Tolerance of individual materials

The following tables illustrate the mutual tolerance between individual materials or with engineering structures. It is an excerpt from ČSN 73 3610.

 The D.4 table specifies whether materials of sheet-metalwork structures can be in mutual contact.

Table D.4: Mutual influence in the contact of selected metals 

+ The materials can be in contact.
- Contact between the materials should be avoided; strongly influential, electrolytic corrosion occurs in the presence of water.
o Contact between the materials should rather be avoided.

Water running down the copper structures contains ions of copper, which can cause corrosion of aluminium, zinc, titanium-alloyed zinc or galvanised steel, especially if the water runs from larger copper areas. Therefore, the mentioned metals should not be positioned below copper structures.
It is necessary to prevent water running from steel structures without anti-corrosive protection to all types of sheets.

The D.5 table specifies whether materials of metalwork structures can be in contact with selected materials of the sub-base.

Table D.5: Potential effect of engineering structures on materials of sheet-metalwork structures 

+ The materials can be in contact.
- Contact between the materials should be avoided; strongly influential, electrolytic corrosion occurs in the presence of water.
* Wood with pH > 4.5: for example Scotch pine, shore pine, Norway spruce, beech, poplar.
** Wood with pH < 4.5: for example Douglas fir, red cedar, oak, chestnut tree, maritime pine, European larch.
? Potential contact with the sub-base material should be checked with the producer of the coated sheet. 43 ČSN 73 3610