Quartz seam cracking


Better than Granite but not a great material

Quartz countertop material was oversold from the start.   Salesmen would come into the shop claiming scratch resistance, wouldn’t stain, and heat proof.   About a year later the ads started appearing in Kitchen and Bath trade journals saying otherwise as the warranty claims were mounting.

Quartz  countertops are not UV stable, no polyester resin truly is unless they spend a fortune on added chemicals, so sunlight, even what little UV light that comes from florescent bulbs will bleach or yellow the countertop.  Quartz scrap left out side will quickly degrade from direct sunlight, bleaching and cracking the surface.

Quartz countertop materials also reacts to solvents like acetone which will etch the polyester resins, leaving streaks, spots, or dull areas.  The product will etch easily too with acidic foods such as coffee, soy sauce, red wine, or ketchup and other tomato products being the top offenders.   Any sort of metal can can leave rust stains, even hard water is notorious for leaving spots and streaks or rings around the faucet components.  Rechargeable battery chargers will put off fumes that will etch quartz countertop back splashes and the quartz  countertop beneath the plug in charger

Quartz is a mixture of polyester solid surface and quartz chips, around 7% polyester by weight, between 28% and 35% polyester by volume which they forget to mention in their marketing.  Any mixed product like this must have some thought put into it, especially on the co-efficient of expansion of the two products which is the rate of expansion and the reason for the expansion to prevent the product from ripping itself apart as the temperature changes. An example of a combination that works is reinforced concrete, concrete and rebar have the same co-efficient of expansion

Quartz expands more and faster than polyester which is why that quartz top on the top of the page had a big quartz chunk pop out.   Good fabricators will warn you to never drag anything across a quartz countertop, especially a metal pan, not because the metal will scratch it but because the likelihood of a loose quartz chip popping out being under the  pot and causing a scratch.

Very low temperature changes such as when buffing an area of a quartz top or even friction from the tie down straps used to hold a top being transported can and have left marks that can’t be removed.  Online forums have a number of consumers that have had to have their tops ripped out and replaced over markings on the top caused by low level heat, attempts to polish, or attempts to fix a dull spot or scratch.   One company has claimed to have developed a paste or cream for top polishing quartz countertops but the reviews are mixed as some colors can be polished by an experienced technician but you are rolling the dice if you try.

Why not quartz?

  • About half of the time quartz countertops will  stain quite easily, which half is anyone’s guess
  • Heat will ruin it quickly
  • Seams are not guaranteed, they will break eventually
  • Quartz popping, scratches, not repairable
  • Etches easily with common chemicals, turmeric, coffee, red wine, even hard water will leave spots and glass rings

The difference in co-efficient of expansion is also the reason that quartz countertop seams are not covered under their warranty.  As the two materials expand at different rates the glued joint will rip itself apart.   A house in Nichols Hills that we redid a few years back had had new quartz countertops installed throughout the home about four years earlier and every single seam had broken. 

Quartz countertops scratches and damage is not repairable because the super hard quartz chips and the soft polyester don’t polish at the same rate and the minor heating caused by the polishing changes the color of the polyester.  This is well known and understood in solid surface work, if you are going to heat and bend part of a job you need to heat all of the parts that are seamed to the heat formed part because the heating will change the color slightly.

Polishing quartz countertop edges is okay because all of the edge gets polished and there  is a break between the polished edge and the top of the countertop.  While you are polishing you are rotating the water fed diamond pad grinder up and down across the edge but if you go too far on a single pass of the grinder and get up on the top you have ruined the countertop and must start over with a new slab of material.

Quartz countertop material is also notorious for cracking and warping due to internal stresses.  The sheet is poured and cured then ground down and polished at the factory.  Once you cut that large slab down into parts for smaller countertops you redistribute the internal stresses caused by the curing and polishing.  The two ends of a seam might not be flat, one might be bowed up or down,  creating a ridge when you slide a plate or your hand across the countertop seam.  If you force it flat using vacuum clamps and trust the polyester resin to hold against that sort of pressure you will eventually pay the piper.  They call the glue epoxy but it is really polyester plastic that sets up into a glue.

Quartz  countertops stain quite easily.  The online forums are full of horror stories where one customer has no problem and the next customer has to treat the countertop like it is fine linen to prevent stains.  Once a consumer called in asking about heat damage to his wife’s new quartz countertop.  She had gone on a business trip and had warned him about hot items on the top.   The guy had set a cup of coffee on the top in several places while fixing lunch and left a series of rings, most likely a combination of low heat and acidity from some coffee on the bottom of the cup.  His goose was cooked and he was reaching out for help but as it is nearly impossible to top polish quartz countertop materials unless you re-polish the entire top to deal with the color change there was no good news for the guy. Cleaning products are also a source of a lot of phone calls and emails on quartz countertop problems.   Murphy Oil Soap is a common culprit.  The care and cleaning instructions always warn you not to use any cleaner that is alkaline or acidic, well almost all cleaners are alkaline such as soaps or detergents.