Heat resistant worktops: what about granite and quartz?
Kitchens are rough places, with all kinds of stresses and threats to the kitchen units, the worktops, and to the cooks and bottle washers who do the work! Hot objects are one source of potential danger, and some of our most frequently asked questions have to do with heat and worktops. Here are three common ones:
Can I put a tea-pot or make hot drinks with the mug directly on a granite or quartz worktop?
Yes, you can. With both granite and quartz worktops there is no need to worry about temperatures up to boiling point and beyond.
For quartz that means up to 120°C. Tests run by Cosentino (makers of Silestone) show some significant changes in the surface of the worktop above that temperature. They may not be readily visible, but with the passage of time even mildly over-heated areas may begin to be harder to clean, showing up stains and dyes more easily.
Granite can go far hotter, but only if heated slowly and across a wide area. It is even possible to cook steak on a granite worktop with a blowtorch underneath – but only by raising the temperature slowly and steadily, and we don’t know any practical kitchen use for this fact! You have to be careful with very sudden, localised heating – see notes below.
Can I put a saucepan or casserole straight from the hob or oven onto a quartz or granite worktop?
Quartz worktops contain a plastic resin. As such, they are susceptible to scorching under extreme heat. We do not recommend that a recently heated saucepan, or a casserole straight from a hot oven, should be placed on a quartz worktop.
Granite worktops are heat-resistant to a higher temperature than quartz. In general, hot pans will not damage a granite top. All the same, we recommend the use of a trivet, especially where the worktop is particularly cold.
The possibility of heat damage is because of rapid thermal expansion. Rapid expansion in the crystals near the surface of the kitchen worktop can cause a tendency for them to sheer away from the layers below. This can lead to a breakdown of the surface – at the least a change of colour where gaps between crystals become visible, and, at worst, actual disintegration of the surface layer. This process is actually used where a flamed finish is desired – a blowtorch played on the surface causes crystals to break away, creating a beautiful, stippled surface.
Is there a worktop which can take hot pans without worry?
Yes – if you are desperate to put the hottest pans in your kitchen straight onto the worktop and have a deep-rooted desire never to use a trivet, then you have to consider ceramic-style, sintered-particle surfaces like Dekton®, Neolith and others. These materials contain no plastic and are manufactured under conditions of immense heat and pressure. If heat is the biggest threat in your kitchen, then ceramic is the way to go.
Granite worktops in the extreme
What was our most extreme example of heat resistant worktops?! It was also an extreme example of temperature related damage. We had installed some Blue Pearl granite worktops in a country home near Horsham in West Sussex. Some years after installation, and with all of the family out, their kitchen suffered fire damage. A tumble dryer left running had unfortunately caught fire. The flames spread into neighbouring units, but the granite worktops contained the fire, until a neighbour saw the smoke and called the fire brigade.
It was only when water from their hoses hit the extremely hot worktops that the granite finally cracked – the sudden shock of the cold water causing rapid contraction and internal tensions in the stone that even the extremely tough Blue Pearl could not withstand.
After making their insurance claim, the owners came back to us for their replacement worktops, in the same lovely granite. They reported what the fire fighters had said: “Granite worktops saved our home!” An unusual recommendation, but one we treasure!
If you want more information on heat resistant worktops or any other kitchen worktop issue, just browse our FAQs or give us a call! We are here to provide the kind of technical information and design advice that can give your kitchen not only practicality but the wow factor too. Email us at email@example.com/ or call us on 01293 863992