We placed our hood before installing the backsplash, to see exactly where it would land on the wall. Then we did the blocking behind the wall and marked where the screws needed to go.

Then when we tiled, we cut the tile around those portions so that we wouldn't have to crack any tile when drilling. Hoods are each installed a bit differently depending on the manufacturer; ours was hung by a long metal piece screwed into the wall; we attached that on top of the finished tile via those untiled screwhole spots. It's all invisible when the hood goes up.

Oh yes, PS - the chimney, which is generally purely decorative and just covers up the actual ducting, only attaches at the bottom onto the hood itself and at the top on the ceiling -- no need to screw anything into the wall for that piece. Hope that helps!

Live_Wire_Oak, I'm hearing that I will have to drill through my backsplash, is that correct?

This presents a big problem being that we were going to DIY back painted glass. Even if I have the glass custom cut, I can't see how we could accurately enough give them the mounting holes. There would have to be some slop factor or a much bigger hole then necessary. I know glass can be cut but I don't think it can be drilled, can it?

Aloha- These are all good questions and I do not have the expertise to answer them...but, I would think someone could drill into glass, but maybe not a DIY project. Something to possibly ask your glass installer about.

I'd also talk to the hood installers and see if you could vent out the roof, or if you still have to attach it to the wall. Let us know what you find out, because the glass backsplash looks like it's becoming a popular option :)

Glass can be drilled, very carefully with the proper bit and the proper handling. But, better you than me.
There are similar-looking hoods that mount to the ceiling in their entirety, (island types) that have in general the same appearance of your style, but would avoid the BS contact problem.
Casey

Yes, this is a difficult job for even pros, and that's why the price is so high for glass sheet backsplashes. It isn't DIY friendly at all. It takes specialty paint to stick to the glass, and not come off when the adhesive is applied. It's hard to have a wall be prepared flat enough for sheet glass, and cutting holes in it is difficult.

I would suggest using the sheet safety glass up to the height of the bottom of the hood and using another material from the hood portion and up. Mix it with glass mosaic in the same color at that point? It would lend an interesting textural element to mix the sheet and the mosaic.

Circuspeanut, thanks for explaining how exactly those hoods are mounted. We were clueless.

Lavenderlass- I have to laugh when you talk about various installers since WE are the installers for most everything.

Sombreuil, since the wall mounted hoods are cheaper perhaps we can tweek it to not needing to be attached, but we this is getting into a huge mess.

Green Design we had colored in a back splash on paper and preferred it to the ceiling but with hearing all this, we may just concede to it just up to the vent. With it being rounded, I'm don't know if the backsplash would look best with a round top or squared off. I guess I can get my color pencils out and check it out.

I guess it's looking like we may have to concede on part of this look :(

The good news though, I did a slop job on an old piece of glass. Spray painted it w/o even priming it. It looks super. We were going to prop it up where the steam comes out of our current oven to see how much abuse it can take. My DH scratched our names on it like sweethearts do on a tree (he's such a romantic) to see how it came out. He really had to scratch hard to mar it up. I was going to re spray paint it to see how fixable it is.

Green Designs mentioned safety glass. Just FYI you can't cut or drill tempered glass. You can drill non tempered glass with a diamond bit. You need to keep the glass wet while you're drilling. Would be more challenging on a vertical surface such as an installed backsplash, but not impossible. I don't have any experience installing backsplashes, but I have drilled holes in glass many times.

Unless the glass is etched and has a bit of "tooth" to hold onto that spray paint, it will eventually peel off of it. Glass paint is a specialty paint that is baked onto the glass to "stick". Trying to adhere spray painted glass to the wall only increases the chance that the mastic sticks to the paint and not the glass and then the whole shebang falls off of the wall at some point and shatters. Thus the need for safety glass. Plus, if hot grease spatters regular glass, it can shatter due to the thermal shock. Safety glass will still shatter. It just won't cut you into ribbons.

Don't get me wrong. Back painted glass is a stunning backsplash. It's just better left to the pros. Call a glass company and get their estimate for doing the job right.

A bit late to the party, but hopefully the link below help anyone who's googling and came across this thread like I did.

Here is a link that might be useful: How to install range hood over glass panel backsplash