Ralph found a botanist who (amongst other things) said about ivy:

"... the appendages are for attachment purposes, but can be modified
to absorb water when needed.  I think that the real problem arises when
the mortar begins to decay and you begin to build up residue that will
hold moisture for a period of time ..."

I reiterate my points made earlier:

1)  If ivy is on the wall, does this keep rainwater off the wall?

2)  If ivy is planted at the base of the wall, does this suck lots of moisture out of the ground and reduce rising damp?

3)  If (1) and (2) are true, then will there be very much moisture in the joints for the attachments to become roots?

4)  If (3) happens, then will ivy have a bad effect (except for the physical effect of displacing masonry units due to trunk growth)?

Nevertheless, I think a trellis frame constructed away from the wall and regularly chopped out with a long machete or similar must have some pretty good possibilities for giving us ivy on buildings without all of the problems.

Shall we set up a business to design, manufacture and install the ivy trellises?  What should we call it?  BULLAMANKA IVYSCAPES?

Cheers

david

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david west
Arup Facade Engineering
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