Last Wednesday the Stone Federation held a seminar day in London for members about design and installation of natural stone. Amarestone's Director, Steve Turner, was one of a group of five industry experts to present a talk to the assembled stone professionals.
I went along to listen to the talks which featured a range of key topics such as current industry regulation, technical specification, problem solving and general best practice. As always, the team at the Stone Federation did an excellent job of hosting the event and their collective enthusiasm for raising standards in the industry through knowledge sharing really shone through. Well done and thank you!
I think that a great deal of what was discussed during the day would benefit anyone looking to use natural stone in a project, not just stone industry professionals. If you do work in the stone industry or regularly specify natural stone in your projects as an architect, I would highly recommend that you speak to the Stone Federation for details on how to become a member - it really is a worthwhile investment. In the meantime, here is a brief summary of some key issues raised by the presenters on Wednesday -
As of June 2013, it is a legal requirement for all natural stone advertised for sale in the UK to have a CE Certificate.
The CE Certificate itself does not mean that a particular stone is suitable for your project, it simply states the properties and geographical origin of the material. The onus is on the person specifying the stone to check the details and to ensure that the stone is fit for purpose.
Anyone who assumes the role of specifying natural stone needs to be aware of this and understand that they have a duty of care to the end user. If a product is found to be unfit for purpose and, upon investigation, it does not have a CE Certificate, the person who specified it (usually the seller) is liable for damages.
Correct preparation of the substrate:
Over the last century, we have drastically changed the way that we use natural stone.
Historically, stone was laid on a compacted sand base and thicker slabs were used to reduce the risk of cracking. The stone was not fixed rigidly to a solid base so the sand would absorb any slight movement in the substrate.
Buildings and floors were designed to breathe so any moisture in the environment could pass through the stone without becoming trapped.
However, this method is no longer an option for the vast majority people who want to use natural stone. Nowadays, we are used to the convenience of man made materials that can be applied without the old constraints.
As opposed to the old draughty but breathable buildings, most of us favour a well insulated home. Very often too, we are retro-fitting natural stone into spaces that were never designed to bear the additional weight.
Without proper understanding of the material and thorough planning at the design stage, this tends to cause problems. We regularly come across instances where stone has failed due to inadequate preparation of the substrate or because of poor quality installation.
The speakers all agreed that planning is key to the success of a project and that there are a number of aspects that should be taken into account when using natural stone.
Selecting the right stone for the job:
Every stone is unique so it follows that each one will be more or less susceptible to problems such as staining and will react differently to sealers and cleaners.
The CE Certificate tells us the geological composition, frost resistance and a number of other important details about the stone. However, the presenters all stressed the importance of carrying out tests on a sample piece of the selected stone before going ahead with the installation. The sample should always be from the same production batch as the stone to be used on the project.
If the project involves using stone where it be put under stress in one way or another, it is always worth talking to the quarry and trying to find examples of where that particular stone has previously been used for a similar project.
Examples of uses where it would be helpful to carry out this type of research prior to placing an order include:
- Structural: exposure to wind, rain and pollution; load bearing capacity; frost resistance
- Commercial: slip resistance (usually more to do with the surface finish than the stone itself); durability, particularly where the stone is used as flooring; maintenance, the stone will need to stand up to basic commercial cleaning regimes
- Kitchen and bathroom (especially for worktops and wetrooms): acid etching; staining (this is more about how long the stone is likely to hold the sealer - generally, the softer the stone, the sooner the sealer will need to be re-applied)
Every project is different and natural stone can be used in so many diverse ways that it is very likely that some degree of research should be carried out before an order is placed.
At Amarestone, we always ensure that our recommendations meet the technical requirements of a project. This usually means consulting the quarry before putting a stone forward to the client and, where applicable, we try to find examples of where that stone has been used previously for a similar project.
For more information on any of the above, you can contact the Stone Federation directly or speak to Steve at Amarestone.
If you would like to know more about how we source natural stone for projects, please download our brochure or just phone or email for a chat. We're always happy to talk about natural stone!
Thanks for reading. If you have any questions or comments, please feel free to post them below.
Tel: 0345 260 8070