snecked rubble step by step
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Snecked Rubble WallingA step-by-step guide for stonemasons
Stonemasonry Department 2013
The aim of this presentation is to introduce you to the method of building snecked rubble
walling against a block backing. By the end of the lesson you should have developed an
understanding of the bonding arrangement and process for constructing this type of walling.
The first course is built using a repeating pattern of one riser followed by three levellers. You
should see that at the stop end of each of the returns the pattern is stopped but if the wall was
longer this pattern could repeat indefinately.
The second course consists of arrangements built between the risers of the first course. This
arrangement will continue throughout the remainder of the wall. Between each riser there is a
sneck, then a riser, then two levellers. Remember the minimum overlap is 100mm.
The third course is similar to the second. A sneck is followed by a riser and two levellers. You
may find that more cuts are required on this course as you need to ensure that the bonding
requirements are followed. Remember there are a maximum of three heads to a joint.
As you progress higher up the wall you should see that the pattern continues; sneck, riser,
leveller, leveller. By this stage of the construction you should be becoming more familiar with the
bonding arrangements and able to plan each course with the next course in mind.
The main challenge in maintaining a regular bonding arrangement is making sure the bond is
maintained at the returns. The external return in particular requires careful consideration as the
external arris must always be plumbed and minimum overlap adhered to.
As you approach the top of the wall you should see a pattern emerging where the position of
the risers form elongated diamond shapes. You should also notice that the courses alternate
between 1/3 height stones and 2/3 height stones.
On the second-to-last course the risers are levelled to finished building height. Have you noticed
that the risers have been arranged to form the external return? This is the simplest way of
forming the return as the stones are larger and easier to keep in alignment.
The top course is completed entirely of snecks (or levellers). These are intended to represent the
sneck, riser, leveller, leveller pattern as though they had been built and then cut to form the
finished building height. Once complete you should level the top course and point the wall.
Developed by The Stonemasonry DepartmentCity of Glasgow College
2013