If a person puts his or her hand on their heart and begins to say something you can be pretty sure that what they are about to say is the absolute truth. There are many truths referring to dry stone walls. Wallers may disagree about some of these truths or 'rules of walling' but there is one rule that is pretty much an absolute must – 'A dry stone wall needs to be properly hearted, which requires that there be enough small sharp shaped small pieces so as not to skimp on the filling and pinning of the stones throughout the inside of the wall'.
What do we mean by enough? I would guess that a normal dry stone wall requires that almost a third of the amount of stone used to build it be this small hearting material, being no bigger than small lemons ( and most of it being even smaller) and their optimal shapes being that of lemon wedges.
To find this much small stone is very labour intensive and almost impossible. It's easy to fill a wheel barrow with five medium size stones and it doesn't take any time at all, but to try to fill that same wheel barrow with very small wedge shaped pieces might take over an hour. This is often the problem when gathering material to build a wall – the heart isn't in it.
A wall, if it did have hands and had an opportunity to be truthful would likely put its hands on its hearting, if it had some, and say I am an honest wall because I have been hearted right, and I will stand the test of time. That would be the truth. A wall without much hearting will be an untruthful wall and will probably not stand for much.
I always make sure people have enough of this right type of small hearting material always available in a location near them when they are working . To try to use lots of round stones won't work, even if they are small. The stones act like marbles between the bigger stones causing the wall to eventually slip apart. To try to build without much hearting too, just making do, is often the temptation. I have even seen certified testing where there wasn't enough hearting available for the wallers to build a proper wall. This is not right.
For most of our projects then, over the last ten years the only solution we could come up with for our walls was to have one or two guys making hearting all day by breaking some larger odd shaped rocks up, in order to supplement the inadequate amount of small stones that usually come with a normal tandem truck load of random building stones. There is even a technique on how to hammer rocks so as to make 'good hearting', but that is for another blog post.
Quarries in Ontario, almost without exception, don't seem to specifically make any 3 to 4 inch clear material ('railroad ballast' is the best description for what it is we tell them we would like) which is what we always need for walling. They usually just supply smaller gravel material, or a 3 inch minus material, which means it is filled with tiny stones and dust and 'fines' as well.
But recently we have come up with a source for a very reasonably priced, perfectly suitable, quarried, 'hearting material'. It's really great stuff and makes the wall building go so much better. We now have several tons of it brought to every dry stone wall project and that way we free up all the wallers on the job to be just be building and of course doing it 'with all their hearting'. If DSWAC members want to know where they can get this material from, just email us for the information.