Widen hole for cooktop in granite countertop


Old 06-28-19, 01:12 PM
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Widen hole for cooktop in granite countertop

A neighbour asked me for help installing he new cooktop. Although 30in wide, the hole is about 2in too narrow for the new cooktop.

I have done this on my corian counter top but this one is granite. I am concerned that we won't be able to adequately eliminate stress points in the corners. It seems like the granite is supported on all 4 side of the opening.

We can get a diamond circular blade and make the straight cuts but how do we handle the corners?

Is this worth it?
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Old 06-28-19, 04:01 PM
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Is it worth your neighbors future friendship?

Personally that is a favor I would walk away from, the down side is a new granite slab!

Let us know how it works out!

Diamond and or carbide hole saw blades will easily cut granite!
Norm201 voted this post as helpful.
Old 06-28-19, 07:00 PM
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I'm not sure if that would be something I'd attempt either. But if I did..... I would use a diamond or good carbide bit to drill the four corners. Those four holes should eliminate the countertop from cracking.
Old 06-29-19, 03:13 AM
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I would contact granite counter companies and see how much they'd charge to enlarge the opening. They'll probably use a diamond hole saw to radius the corners first. Then they'll cut straights in between with a circular saw and diamond blade. It's something you can do yourself but by the time you buy the diamond drill bit and saw blade you can just about hire a pro to do the job.
Old 06-29-19, 01:05 PM
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He asked me to come over and take a look at it. Turns out it was Corian, not granite. We were done in about an hour. I agree with the hole saw in the corners. I think that would be the only way to do it.

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