Bidet Seats For French Curve Toilets


How do I know if a bidet seat will fit my toilet? This is a common question for those looking for a bidet seat for hard to fit toilets. The most difficult toilets to fit are toilets with a french curve. This curve limits mounting space to an extreme level, and greatly limits the bidet seat options at your disposal.

There is some good news, however. Our favorite bidet seat also happens to be the most likely to fit a hard to fit french curve toilet. Watch our video to learn about what toilets work well with bidet seats, which toilets are problematic, and why they are problematic. We also talk about how to install a bidet seat on a toilet that previously would not work, and much more.

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Common toilets with french curves include:

  • Kohler Rialto K-3386 works with select bidet seats but the seat will have overhang
  • Kohler San Raphael K-3722 will work nicely with select bidet seats
  • Kohler Rosario K-3434 may or may not work with select bidet seats depending on the year the toilet was made
  • Kohler Santa Rosa K-10491 will work well with select bidet seats
  • Kohler San Souci K-4007 will not work, but other versions of the Kohler San Souci toilet will.
  • Kohler San Martine K-3435 is too tight in the back to work with any bidet seat
  • Jacuzzi Primo toilet will work with select bidet seats, but a modification to the mounting plate will need to happen for it to fit

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Hello, this is Daniel, owner of

Today we are going to talk about, French Curve toilets.

Now french Curve toilets are popular in older homes, because of their low back and their fringe curve; Right here we can see the French Curve. It’s a curve that comes around the outside of the bowl.

So unlike a “standard toilet” where the tank is flush back here and just comes straight down and does not impede the toilet bowl. A French Curved toilet curves towards the outside of the toilet bowl, making space in the back very limited.These French Curve designs are stylistically very pleasing to the eye, but it makes for a tricky bidet installed. Not only are bidet seats hard to install on a toilet like this, but in general these toilets because of their low back, don’t offer great flushing power either. So there’s a couple of limitations that you get when going with a toilet like this.

There aren’t that many of these toilets on the market anymore, most of them are in older homes, but if you’re looking at installing a toilet in a newer home there are still a couple models of French Curve toilets that are available.

It’s also important to note that when we use the term ‘French Curve’, we’re talking specifically about the curving around the outside of the bowl, like we see here. We are not talking about where the tank comes down and curves this way. Now that can be a problem on some bidet seats that are a little bit less versatile, but when talking about French Curve we are specifically talking about the curve around the outside of the bowl. So, i think i’ve, i think we’ve clearly talked about what a French Curve is, hopefully that all makes sense for you.

Let’s go and talk about putting a bidet seat, on a French Curved toilet. So, you can see here our mounting plate and this mounting plate has to mount onto, the toilet bolt holes and then the seat has to slide in on it. Well this is a standard, very very standard mounting plate. Well what’s the problem with this mounting plate? Well, it’s square, it’s large and those French Curves start, right up in here on most French Curved toilets. So you really have very little wiggle room to work with. So, I can’t even get this mounting plate to sit flush against the porcelain and get both holes inside of the needed window, to install this mounting plate. Now let’s say that, by chance, I was able to… What would mounting the seat on it look like after the mounting plate was installed? This DIB-850 is actually a little bit slimmer in the back than most bidet seats. So you would think, I have a good chance of getting this to fit on the French Curved toilet. Well let’s take a look; so we’re going to go ahead and put this on, and you’re going to see that, we don’t really have a good fit. So because the sides of the bidet seat hit the sides of this French Curve, the bidet seat is not able to slide back far enough to clip into the mounting plate. So even if we were able to slide it into the mounting plate a little bit, this bidet seat would slide freely and it wouldn’t even be connected to the toilet. So bidet seats don’t really work well with a French Curved toilet.

However, there are a few exceptions.

Our favorite exception to the rule is called the Cascade 3000. Here’s the Cascade 3000s mounting plate, let’s compare the two. Look at the size difference of that mounting plate, look at the curve in the back of the mounting plate, both great things when we’re talking about a French Curve. This gives us more room to work. The length of the mounting plate says where it’s going to fit, and the size of the mounting plate in the curve in the back says how it’s going to slide in and out. So this mounting plate can actually rest flat against the porcelain, on most French Curved toilets, so let’s take a look here. So you can see how that mounting plate looks on that French Curved toilet and it’s actually got some wiggle room. It’s got some back and forth, not a lot but it has some back and forth,that’s the mounting plate all the way back. So you can see we’re looking at, a half an inch a quarter inch of space, where the mounting plate has wiggle room on this toilet. So quite a bit to work with there with this particular mounting plate, again this is for the Cascade 3000 which is our top pick for French Curve toilets. Here’s the Cascade 3000 seat so what we would do (is pretend that this mounting plate was actually screwed on) we would simply slide the Cascade 3000 into the mounting plate, and when we do that we’ll hear it click. Now on this particular toilet you can see there’s still a little bit of overlap in the front, but the bumpers are resting on the bowl. You’ll also notice though, that as we spin it, that it’s able to sit back further than the other bidet seat that we showed a moment ago, because of how curved it is in the back. So this seat is more curved in the back and has a more curved mounting plate and because of that it can sit further back on, this toilet making it a fit. Now some French Curved toilets will be a perfect fit, other French Curved toilets with the Cascade, you’ll see some overlap in the front. This is one of those tighter models, you’ll see some overlap in the front.

Furthermore, even if you know the make and the model of your toilet, different years of the same make and model have slightly different stylistic designs, especially when you’re talking about some of the Kohler French Curve toilets. So we might say well most versions of “x” toilet like the San Rafael, most versions of the San Rafael work great, but there are a few years that that toilet was made where there might be problems. So, it might fit but it might have overlap in the front or it might fit better and all of that just depends on how sharp this French Curve is in the back. Depending on how sharp that French Curve is, we’re going to have a better fit or worse fit.

There’s also something else to bring up, and that is, on this mounting plate (again this is the Cascade mounting plate) there’s quite a bit of wiggle room here in the back. So, compared to a standard mounting plate where it’s very thin here in the back, and again much wider and compare that to the Cascades mounting plate where there’s some wiggle room here in the back and it’s shorter as well as curved. There are specific toilets like the Jacuzzi Primo toilet, which is one of the few toilets made today with a French Curve, where this curve in the back is just too tight to install the mounting plate and slide the Cascade into place. But it is close enough, that if you were to take tools and cut out a little bit further back on this mounting plate, and cut back a little bit further on the layer below to make the groove longer you can actually make this mounting plate work for a toilet like the Jacuzzi Primo. Despite the fact that out of the box it might not. So, French Curve toilets, you have the curve in the back and depending on that curve some French Curve toilets will work with the Cascade 3000.

Also would work with the Blooming or the Galaxy so there are three seats on the market that French Curve toilets can be paired with. Again the Cascade is our pick, for a variety of reasons. Feel free to visit our website and live chat with us as to the reasons why.

But, not all French Curve toilets are created the same. So this curve may be shallower or steeper and depending on that curve you may find that even the Cascade may not fit your toilet. So you may be looking at if it’s really really close like with the Jacuzzi Primo, you may find yourself cutting out a little bit of this mounting plate and then mounting it (that does work we’ve had customers do it and have success) or you may find yourself needing to replace the toilet. So, if you know the make and model of your toilet, visit our site, chat with us. We are experts on the French Curve design and which toilets will work well, which toilets won’t. So come chat with us, talk to us about whether or not you have a toilet that will work well. If it’s not a toilet that will work well we can still talk about replacing it with a toilet that would.

Hopefully you found everything that we talked about today helpful, and informative. Again this is Daniel Johnson, owner of Many Bidets, thanking you for watching our video about French Curve toilets and how they work or don’t work so well with most bidet seats on the market. Check out our Cascade 3000 and how that pairs with your French Curve toilet.

Thank you for watching, don’t forget to subscribe if you’d like to see other videos about hard to fit toilets, installation, troubleshooting, cleaning and maintenance and a variety of other helpful videos. Thanks again and have a great day!