When calculating the amount of Natural Stone Tile or Pavers you need for your project ordering the correct amount of overage is an important part. There is a rule of thumb within the industry when working with Travertine, Limestone, or Marble Tile which is ordering at least 10-12% overage for your project. This overage is important to cover waste, miscuts, and any material that is broken or chipped during installation or when pulled out of the pallet. The main focus for this is making sure you have the correct amount of material to properly complete your project and that you're not left short which can cost you time, money, and frustration.
This rule of thumb is the same whether you're working with your local supplier or found an option like Rock Bottom to have your material delivered direct to you. Any type of tile that you work with from Travertine, Limestone, Marble, Slate and even Porcelain are all susceptible to a small amount of breakage both during transportation and during the installation process. Cuts will get missed, measurements might not be right the first time, and there can always be more waste than you initially think depending on how many cuts need to be made. You have to also remember that all of these stones are taking longer trips around the world than most of us will ever take so that is a lot of traveling and handling before it makes it's way to the stone yard and your home.
It is absolutely better to have a little extra tile left over than to be put in the spot where your project cannot be finished on time and could even run into an issue with availability on the same product or color lot. We have had very few customers run into any issues with that when calculating at least 10% overage for their Travertine, Limestone, or Marble project. For interior tile these are all usually 1/2" material so while of course being fragile they are still pretty dense and strong.
The one exception on the overage amount would be for Slate which we recommend at least 15-20%. The majority of Slate tile is a little thinner at 3/8" thick and slate is also more of a layered or flaky type of stone which can make it a little easier to break. You will definitely find more chipped and broken pieces with Slate than you will with Travertine, Limestone, or Marble.
Scenarios where you would want to consider ordering more than 10% overage for Travertine, Limestone, or Marble projects are when you are trying to ensure a more consistent look or if you are ordering material for a smaller project. A major part of the beauty of natural stone is its uniqueness from piece to piece making each tile different but for people that want to try and ensure a more consistent look we would recommend a larger amount of overage which gives you more leeway to select the pieces you want to install and leave out any that you don't think fit for your look. For smaller projects you would want to consider ordering at least 15% because that will provide your installer with more room for error when working with a smaller amount of material.
The 10% overage rule also applies to exterior landscape pavers and pool coping. These are very durable products but again you want to ensure you have enough material to cover all the waste and any breakage that might happen during installation. With landscape pavers it is also always really nice to have spare pieces left over just incase any material cracks after installation it can easily be replaced.
Following these guidelines for calculating the proper overage amount for your project can help avoid issues and headaches associated with coming up short during installation. Your project already has enough going on without added delays, cost, and frustration to the process. Always check and double check your numbers prior to ordering and always err on the side of more material when finalizing your number.
Hopefully, this helps you with ordering the correct amount of overage for your tile project!