[DIYOkie]

We have 3/4" granite countertop in storage we're wanting to install for our kitchen. We bought it used. It was taken out of a fancy hotel during their remodel so we got a good deal on it.

It has 3/4" plywood apparently glued to the bottom of it.

My question is about the island. It is going to hang over one edge about 12" to make a good ledge for dining, or what not.

Am I supposed to cut the 3/4" plywood support 12" back so it's just granite hanging over for the ledge, or am I supposed to keep that 3/4" plywood as additional support for the ledge? I just don't see how plywood helps support anything as a cantilever.

I am also assuming I need to support this ledge with some brackets, regardless.

Any help would be appreciated, as always. Thanks.

 

[Nealtw]

I would just paint the plywood so it isn't obvious.

 

[Old Thomas]

Is the edge covered? If the plywood will not show, leave it. We regularly overhang 12” of granite with no supports, but it is thicker than 3/4”.

 

[chandler48]

You may want to consider installing a couple of corbels to aid in the support. Granite can snap real easily, even with the plywood underlayment.

 

[huesmann]

No matter whether the plywood will show or not, you can't remove it. 3/4" granite isn't strong enough to go without a substrate.

Chandler's idea is a good one, or you can run some square tubes across the entire counter to support the overhang. Easy to fasten since you've got the plywood to screw into.

 

[DIYOkie]

Thanks for the replies fellas.

Yes, I planned on installing brackets, or corbels I guess (or square tube - good idea), no matter what. I assumed they would be necessary.

And that's partly why I wasn't sure if I should leave the plywood on the ledge - because it's a cantilever. I don't see how plywood actually contributes any support as a substrate for a cantilever since it bends and flexes and granite does not.

But that's cool, I can trim it with something, make it look nice.

So I'll just leave the plywood on there. Thanks again!

 

[lauriejustinmat]

I would advise you to just leave the plywood as this helps in the prevention of cracking. As far as I know, granite has this tendency to crack when there are areas wherein it is not supported. Repainting it just as what Nealtw suggested is on point in my book.

 

[MTN REMODEL LLC]

We have 3/4" granite countertop in storage we're wanting to install for our kitchen. We bought it used. It was taken out of a fancy hotel during their remodel so we got a good deal on it.

It has 3/4" plywood apparently glued to the bottom of it.

My question is about the island. It is going to hang over one edge about 12" to make a good ledge for dining, or what not.

Am I supposed to cut the 3/4" plywood support 12" back so it's just granite hanging over for the ledge, or am I supposed to keep that 3/4" plywood as additional support for the ledge? I just don't see how plywood helps support anything as a cantilever.

I am also assuming I need to support this ledge with some brackets, regardless.

Any help would be appreciated, as always. Thanks.

It's close , but you have 2 cm granite rather than 3/4".... Unless there is some quarry I've never run into.

You are dead right that with a cantelever you will need support with any 2cm rock.(Different rock has different streangths, but 2cm is too weak for a cantelever.)

Without knowing your exact installation, I'd leave and trim out that existing plywood to look good and still use some good strong supporting corbells.



.

 

[DIYOkie]

It's close , but you have 2 cm granite rather than 3/4".... Unless there is some quarry I've never run into.

You are dead right that with a cantelever you will need support with any 2cm rock.(Different rock has different streangths, but 2cm is too weak for a cantelever.)

Without knowing your exact installation, I'd leave and trim out that existing plywood to look good and still use some good strong supporting corbells.



.

This has been installed now. Turns out, the front and back edge of the island counter top was trimmed out with granite to hide the plywood, leaving only the two sides exposed. So I trimmed those back about 1" from the edge and will use a little piece of trim on each side to hide that.

Corbels being shipped at the moment.