A Diocese of Lichfield investigation into the number of unstable gravestones in a Wolverhampton churchyard has blamed poor installation by the original stonemasons.
About 40 per cent of the memorial stones in Wombourne Churchyard failed safety tests carried out by South Staffordshire District Council.
In November last year, the diocese announced it would investigate. The Archdeacon of Lichfield, the Ven Chris Liley, commissioned a report from a West Midlands stonemason.
His report prompted a more detailed study by both the National Association of Memorial Masons (Namm), the professional body representing stone masons, and the Institute of Cemetery and Crematorium Management, representing operators of burial grounds.
Both of the reports blamed poor installation.
The report from the Institute of Cemetery Management said: "For many years lawn type memorials have been removed from cemeteries and churchyards in order to place additional inscriptions.
"Over the course of time it has become commonplace to simply cement the memorial to the foundation rather than fix using the traditional method of installing dowels in the joint.
"Properly installed dowels assist in supporting the memorial should the cement joint fail.
"Most lawn type memorials appear to have been installed simply using cement in the joint between the memorial base and the foundation, making removal easy.
"Water then gets into the joint, freezes and the joint eventually fails."
The Namm added: "A lot of lawn memorials were loose at the joint between base and foundation and most showed evidence that the cement joint had failed some time ago."
The two organisations were also asked to investigate the testing methods used by South Staffordshire District Council but both concluded the council conducted the tests to a high standard.
Last night the Diocese of Lichfield said it would consider licensing stone masons before they are permitted to carry out work in Church of England churchyards.
Kevin Hartley, Chairman of the Diocesan Advisory Committee (DAC) said: "Families pay a considerable amount of money for memorial stones and they expect them to last for more than a few years.
"We need to consider whether we should advise the Chancellor that only those masons prepared to give a written guarantee that their work will be executed to Namm standards should be given permission to carry out work in the churchyards of the diocese.
"We also need to consider whether a legally binding guarantee that memorial stones which fail within a certain number of years should be rectified by the original stone mason at no cost to the bereaved should also be imposed."