Anton Matthews, proprietor of the Memorial Stone Centre in Bognor Regis and inventor of the Stone-Safe memorial fixing system, has carried out another demonstration to show ground anchors, commonly used in the fixing of memorials, can be an inadequate way of securing lawn memorials safely. This time he put his Stone-Safe memorial stability system up against a ground anchor approved by NAMM (National Association of Memorial Masons).

Under these conditions, the result seemed unequivocal. His Stone-Safe system hardly moved at the BS 8415-required 150kg loading while the ground anchor resisted a maximum 63kg before failing. The short video below shows the tests being carried out on a windy day in Bognor Regis, where Anton is based.

NAMM, which this time had representatives among the people witnessing the demonstration (it did not attend the last one in April) once again cried ‘foul’. Keith Rackham, one of the NAMM representatives, said no self-respecting memorial fixer would have used only one pin in the ground conditions presented and would have used 1m long ground anchors rather than the 700mm anchor used in the demonstration.

The chairman of the British Standards Institution (BSI) committee responsible for BS 8415, Alan Burbridge, also attended the demonstration. Speaking unofficially at the event to others who attended, including local authorities and funeral directors, he made the point that a British Standard should not rely on the discretion of the people carrying out the work.

The British Standard requires memorial fixing systems to be tested in ‘medium sand or gravel’. NAMM maintains those conditions are met at the Northampton cemetery where it has tested the ground anchors it has approved – which includes Anton's Stone-Safe method that NAMM acknowledges is a safe method of fixing memorials. NAMM has had the ground conditions at the Northamptonshire cemetery verified by an independent engineer.

Anton says the ground at the cemetery where NAMM conducted the tests contains roots and rocks that strengthen it and is pushing for the British Standard to require tests to be carried out in pits dug for the purpose and filled with medium coarse sand (which is how he carried out his latest demonstration on 27 August) so that the conditions are consistent and repeatable.

He dug two pits, one to accommodate his Stone-Safe fixing system and one for the NAMM-approved ground anchor system. He tested his own system first, which showed minimal deviation when it was loaded to 150kg, the load the British Standard requires memorial fixings to resist.

He invited NAMM to fix the ground anchor system following its criticisms of the way he had carried out the fixing during his previous demonstration (click here to see the report from last time). The NAMM representatives declined the invitation, saying they were there only to observe. Anton and a colleague installed the ground anchor system. It failed at a maximum loading of 63kg. The contrast with the Stone-Safe system was striking.

NAMM has staked its reputation on testing and approving memorial fixing systems. It charges to test them and some of its members make the ground anchor systems that have been approved.

NAMM points out that since ground anchors were adopted as a standard fixing system in the 1990s there have not been any major incidents involving a lawn memorial fixed using a ground anchor – and these ground anchors are intended only for use with lawn memorials.

Certainly using a ground anchor is better than using nothing as it results in the memorial failing slowly rather than failing catastrophically.

Anton developed his Stone-Safe system because he doubted the efficacy of ground anchors, especially in some of the sandy cemeteries where he was fixing memorials, such as Redhill. He took an engineering approach to the problem – and others have commented to NSS that the ground anchor is a fixer’s solution, giving the user a quick and easy-to-use product.

Stone-Safe does take more time to install and, according to Anton, costs about £10 more than a ground anchor. It requires the drilling of holes in the ground for filling with mortar to accommodate dowels in a cast concrete foundation. Dowels are then fixed by resin into holes drilled in the base of a headstone. They are positioned through holes in the concrete foundation and are bolted in place underneath. The bolts mean the headstone can be removed easily for subsequent inscriptions but are hidden from view so are not liable to be tampered with.

A ground anchor is simply knocked into the ground through a base. It sticks up through the base and the headstone is located on to the protruding section. Mortar is used to hold the headstone in place.

Mortar is used so that the joint can be broken relatively easily in order to remove the stone if a subsequent inscription is required. When a headstone is removed for another inscription, it should be replaced using a new base and ground anchor, whereas the StoneSafe memorial can be replaced on the existing foundation.

Stone-Safe carries a 30-year warranty and is microchipped, confirming its authenticity and the underwritten responsibility for insurance purposes.

At a previous meeting of the BSI committee responsible for BS 8415 NAMM had been asked to re-test the ground anchor systems it has approved but it decided not to do so, standing by its original results. Anton has always argued that ground anchors cannot be relied upon to meet BS 8415 in the soil conditions required by the standard, which are deliberately intended to be some of the worst a mason fixing a memorial will encounter – the idea being that if a fixing system performs adequately in these conditions it will work in any soil conditions.

*****************************************************************************

In the September NAMM Newsletter, National Executive Officer Phil Potts reports: "NAMM have received several enquiries following the demonstration of Ground Anchor testing by Stone Safe which took place on the 27 August 2014 and the subsequent Natural Stone Specialist article stating that ‘It would appear that the NAMM approved system failed to reach the BS 8415 standard’.

"Representatives from NAMM Technical Committee attended the demonstration as observers and have produced a full report on the questionable demonstration which has been forwarded to the British Standards Committee.

"The reference by Stone Safe that “the sandpit contained ‘course sand’, which is the criteria in accordance with BS 8415 when testing ground anchor systems’ ” is extraordinary as these test conditions do not exist under BS 8415 or indeed replicate any cemetery or churchyard in the British Isles.

"NAMM would like to confirm that all Ground Anchors that are NAMM accredited have been tested to the current British Standard 8415 and witnessed by an Independent Structural Engineer. The NAMM CoWP [Code of Working Practice] gives a number of alternative fixing options when installing a memorial on soft grounds; if in doubt check with the ground anchor manufacturer.

"No injuries have occurred since the introduction of the accredited ground anchor systems when correctly fitted to manufacturer’s specifications, and NAMM believe that motivation for this demonstration is solely a vested commercial interest in trying to discredit the BSI Committee and the current Test Procedures."

******************************************************************************

In response to NAMM's comments in its newsletter, Anton Matthews wrote to Natural Stone Specialist magazine on 2 October:

The facts relating to the Stone-Safe ground anchor pull test on the 27 August 2014.

The purpose of the test was for NAMM to prove that the pin accredited fixing method complies with British Standard 8415. 

Fact – The reference to the soil condition used for the test is clearly stated in BS 8415 2012 as being medium coarse sand (sharp washed sand).

Fact – The test method adopted was carried out strictly in accordance with the advice given by the construction and testing section of the British Standards Institution.

Fact – The site was fully prepared for a suitable test condition:

1. Width and depths of the pits, in order to allow a free flow of the pin or anchors.
2. A moisture probe reading was taken showing conditions of the coarse sand to be wet
3. The specification of the Stone Safe base regarding weight, size and further dimensions was given
4. The test calibration certificate was shown.

We would further add that the chairman of BS 8415 of 2012 attended the demonstration and approved the test site. Professor Stuart Moy, a BSI committee member, was also there.

Fact – Stonemasons are well aware of sandy soil, poor soil and extremely wet conditions in cemeteries and churchyards in the British Isles, especially during the winter months.

Fact – The chairman of BS 8415 2012 informed everyone at the demonstration very strongly that any approved anchor system must be suitable without modification to stand up in all soil conditions.