Replace your sink with an apron front and two 5" seams. I just added three feet to your slab.

Ok, I will upload a pic of where I'm thinking i could add the backsplash to give me the length i need for the peninsulas to be

The backsplash would go against that back wall in order to give me the length. I was thinking of using the same quartzite 5" in height along the bottom of windows as a backsplash and the length would be the width of the peninsulas then butt the slabs against the backsplash.to give me the extra 1 1/2 inches I need to end the peninsula in a waterfall finsih...I hope I'm describing my intentions clear enough?

Skip the waterfall, unless your house is a slick modern Miami house/condo.

What kind of seam are you expecting at the waterfall joint? There was a post a few days ago with an awful looking quartzite waterfall seam.

Found it:

https://www.houzz.com/discussions/kitchens/p/120

WOW..that was not acceptable either....what I'd like is an angled waterfall..like at a 45 degree angle

I have no opinion on whether or not you should do a waterfall edge,
but it seems that you could use a piece of wood the same thickness as
the stone, and almost as wide, against the wall (brown block). Butt the
slab up to it, maybe leaving a tiny gap for expansion. Install the 4"
backsplash on top of the wood, then caulk. You would need a piece on the
very end of the splash, to cover the wood block. (Cut the wood piece
short of the edge of the countertop.) Or, you could cut the
backsplash piece with a 'tooth' to fit over the wood filler piece.You
might also need to screw wood pieces across the width of wider
cabinets, to support the stone at the back of the cabinets (tan block).

After seeing pics of some of the seams and cuts fabricators try to pass off on consumers, maybe that would just be asking for trouble.

OMG!!!..this is brilliant!!!..when I show my husband, I think he'll be able to do this with the fabricator on board...what do you think of water fall at a 45 degree angle with the quartzite..do you think it would come out good? Or is quartzite too finicky?

This is our waterfall seam. ❤️ it.

Looking at mama gooses drawing I get it - What I don't get is why your original thought wouldn't work with a lot less trouble. I think what you said was to set the backsplash on the actual cabinet (moving it down to fill in mama gooses brown block, and then butt the counter up to that. That seems easier to me (if I'm understanding this correctly).

If the wood won't work, HU-----35, ask your fabricator if he has remnants the same thickness as your stone, which should expand at the same rate. He might be able to cut lengths of stone to replace the wood filler pieces in my drawing. If the seam where the filler piece and stone slab is filled prior to installation of the backsplash, there will be less chance of water using the seam as a channel to the cabinets. Which is the only reason I can think of that HU----35's original idea wouldn't work--water getting through the caulk line and running down the backsplash piece. I would imagine that every cut and every seam will add to the final cost, so although I think this should work, will it be worth it just for the waterfall? Also, as I mentioned before, we see complaints about a lot of imprecise cuts, where counters don't match contours of walls, and these cuts would need to be exact to get the length you need for the waterfall edge.

You would need to have a serious talk with your fabricator, about whether your chosen stone can be cut at 45 degree angle without chipping and cracking.

I'm seeing quartz and quartzite being used interchangeably in some of the replies ...

quartz = man made

quartzite = natural stone

The material is quartzite..I'm a little lost about the water issue..???..on that wall there is no sink..only countertops on both sides and the stove in the

Thank you all for all your input..I'm thinking I have no choice but to have a seam on each side of the peninsulas. We have 4 slabs so the fabricator will have to follow the pattern as best as can be done and just turn 1 slab around and go across 55" wide x 24" depth and then use the other slabs. It'll be seamless on the largest portion of counter top which is 55x 92

@lrod311 - As I understand it now, I think the reason to first put down the counter, and then the backsplash is if there is any penetration from water - even a spill - it will not travel down to the cabinet - If you put the backsplash in first, and then butt the counter top up to it, the only material that will stop any water is the caulk. Makes sense to me now. Will it help if you don't do the waterfall edge? As stated before, it can be tricky to accomplish correctly, and if it would help to have a regular counter, I'd forget the waterfall. FWIW - I only see them done now in very very modern/minimalist spaces.

Thanks again...how about this?..make a 5" border or strip starting from the wall and make and seam the quartzite with the slab at that end of the counter. This will give me the lenghth I need whether I do waterfall or not (which we may consider to abort) loll..this means the right peninsula would have 2 seams ...one going across bc I need pattern matching and one coming fr wall 18"W X 25" length bc I'd hv to start the other slab at the end of the 1st cabinet that's closest to the oven...the left peninsula would have only the top seam going across...this way both countertops would be seamless except for where I joined them at the top?...my goal and concern is following the flow of the quartzite and putting the seam in the least exposed area....??? This whole drama stems from not being able to find at least 2 slabs that were approximately 88 or bigger by 120 in our color ...the only other option is to only have like a 6" over hang for the right peninsula, and just the seam across at the top..the left peninsula is not as wide ..

The orange level shows where the 25" seam will be and the tape measure shows the 85" length of where the other seam will be on the right peninsula

The left peninsula will only have that seam across ...I am hoping this can be done..even if we need to reinforce the open spaces with plywood like that first cabinet has in order to do this..this way the major part of the counter top will be seamless

Yikes - I wouldn't do that.

In finding it hard to visualize your plan but it kind of looks like a letter C with angles? If so, I would either want to opposite L shaped pieces of material that meet to create one seam only or two seams total.

Any chance you could replace the cabinet on the end of each run with a narrower cabinet, so that you would have sufficient stone to make the waterfall or overhang?

Design girl..why do you not agree with the cut???...

AS - I am approx 1 1/2 " short on length and in the pic I posted, I would start the 2and slab after the 1st 18" cabinet in order to keep the pattern...I cannot for the life if me picture the slab turned sideways and able to match the pattern which would just give me 1 seam straight across...I just cannot see how my pattern would flow if the stone needed to be turned to where it's 115 across

What quartzite did you choose? Ours is quartz but has no movement. So that helps. We also chose everything to avoid there being a seam...

I just think a 5 inch seam across the back is really going to look bad. I have to say, i'd rather remake the cabinets than do this. Is this all because of the waterfall edge - if it is, give that up.

HU:

If you were a potential customer of mine, you'd be scaring me because you're venturing wayyy to far into "how" for my comfort. Were I your fabricator, I may give you choice "A" or choice "B", but no way would you be placing seams.

Sure, you're writing the check, but my name's on this thing for eternity. You can have your check back if I don't like your seam ideas. I predict trouble for this fabricator unless he puts this pony in her pen.

Lolll...I'm really not trying to be difficult.. I'm just trying to see if anything can be done with the less seams possible and in the most inconspicuous areas...

Design girl...the issue is not the waterfall at all...but probably the movement in the slab...and trying to put a seam in the least visual space so the majority of the slab is seamless...redoing the cabinets brings more complications like redoing the floor....the biggest thing is we could not find slabs long or wide