In message , cormaic
writes
'Twas Mon, 28 Oct 2002 16:48:52 +0000, when Grunff
enriched all our lives with these worthy thoughts:

AFAIK, that *is* what the are, and if your concrete is indeed only 4"
wide, then it would almost certainly split.

4" *wide*??? I assumed that was an error and the OP meant 4"
*thick*. At 4" wide, it's doing well holding itself together!

I thought something similar.

In that case, I'd use frame fixings to fasten a timber batten
to the concrete and then fix the GH to the battens.

That's exactly what I used to fix my timbers to my concrete block base
wall - of a similar width. Has made a good and secure fixing.
--
Chris French, Leeds