We recently had new custom made cabinets installed. Our stove is in a peninsula. When trying to install the over range microwave/hood combo we purchased, we realized that it had to be mounted to a solid back wall. There is a back cabinet wall, but it is on a peninsula so there is no solid wall with 2X4's behind it. The microwave must be mounted from the top to work in that area. I am looking for an over range microwave/hood made specifically to be top-mounted, or some suggestions as to how to mount one in this space. The dimensions of the opening (HXDXW) are 17"X14"X30"

sounds like that is not going to work. you need a free-standing hood that is supported at the ceiling for this application. take the other back or sell it on Craigslist.

You can add a back to the space out of 3/4" plywood - this will be strong enough to hold the back bracket of the microhood. You can finish off the outside with a matching veneer to the cabinets. Not sure if anyone even makes a top only supported microhood. Even so, you would want some kind of skin across the back so you are not looking at back end of microhood from the back side of the peninsula.

The other thing thought is that the microhood will drop down a lot farther than a standard range hood. This will really tend to close in your view through the peninsula. Is there anywhere in your cabinet layout that you could install the microhood without it being over the stove in the peninsula? Then you could go with a traditional hood over the stove and open things up more.

Tiger,
Can you post a picture of this? You can post one by using the "add attachment" link below the Post a Reply box. You'll probably need to make the picture smaller to get past DIY's size limitations.

In reading your post it sounds like there is a panel that goes between the adjacent cabinets where you want to hang this microwave. Is that correct? How thick is this panel and how is it secured to the adjacent cabinets?

Personally, I'd probably want the view to be open at the peninsula rather than having cabinets and a microwave above. But a photo would definitely help.

Thanks for all of your suggestions. My brother came over and helped assess the situation. There was a cabinet back about 1 inch thick in the area where we wanted to install the microwave. The bracket had holes for approximately 30 screws. He and my husband used about that many 3/4" screws, plus the three bolts through the top of the cabinet and we all think it is very sturdy and that the cabinet structure will easily support that weight. Here is a picture of the finished product. Thanks again.

And here is a picture of the back

I'm sure it will work fine. All those holes in the microwave bracket are there so that at least two can line up with studs behind the cabinet. Since you don't have the option of hitting a stud, you've done the next best thing by using multiple screws into the solid back of the cabinet. The bracket is only holding part of the rear weight of the microwave, most of the load is carried by the two or three bolts that attach the microwave to the cabinet above.