Unable to replace grass with stone

@Nimbindi Not sure if I'm following your description correctly, so I apologize if I'm off-base... did you put the brick trim around the pool? is it possible it wants that space used for the trim in the pool accessories/trim areas in the pool build mode? Also, is the ground possibly hilly and would it have issue with that? Did you try the spray-on stone/bricks? Perhaps that would have the flexibility you need for whatever is the issue that is making it fight you.

@Nimbindi, since @SheriGR has addressed your first problem, I will address your second one. 🙂  The outdoor "room" that are available will usually only work on houses that don't have foundations. 😉 If your house has a foundation (like the one you are using now) then you can either re-create the "room" with the same items (tedious, but at least you get the same look) or you can extend the foundation to cover most of your yard and put the outdoor "room" on that! 😎  Here are some pictures to better explain:

House as is

Option #1: House with "room" & stairs added

Option #2 :  House with "room" added and extended foundation to make backyard cohesive

Same as above but different view

And yet another view

Option #3 :  "Room" recreated by hand to get the same look

Option #4 :  "Room" attached to a house with no foundation giving no height problem

@PugLove888 I'm so glad you clarified that as I had no idea what a 'waterslide room' was. I figured it was something from a pack I don't have and I was literally thinking of a room in the home, so I was way off-base! (I was thinking it was something different than the patio/backyard pack 'slip-&-slide' thing, which I don't have.) 😃 Well, it was also the middle of the night and I was getting a migraine, so there's that too. Couldn't see 'outside the box'. Literally! 😉

Anyway, your excellent explanation makes perfect sense. That thing where ALL of the same floor on any level in any building - or out building - on a property must have matching foundation &/or wall heights per the floor-level wall is annoying. It is nice that you can vary the wall heights on different floor levels, though. But I digress...

@SheriGR, LOL yes, a "Waterslide Room" is not normal thing in real life 😃 (although it should be! 🥳 )

And yes, when I think of a "water slide" I think of a giant one at a water park.  But the one I showed pictures of is a slide with water, so the term "water slide" is logical. 😉  

There are some other outdoor "rooms" in the pre-made room section that you might have since you don't have the Backyard SP.  There were a few outdoor "rooms" with the base game, as well as many other packs.  I think the Romantic Garden and Toddler SPs might have the most.  Here is a picture of a house I made with an outdoor "room" garden that came with Seasons:

I purposely made the house without a foundation in order to accommodate the outdoor garden "room" ! ❤️

And yeah, I had to include pictures since it was too difficult to explain otherwise!  Did you know that sometime next month we are getting a game update that will give us Terrain Tools? 🤨:eahigh_file:  I saw the Maxis Monthly livestream last week announcing this.  It was supposed to come out this month, but had to be delayed since it wasn't quite right yet.  So, this might change this backyard "room" issue and how we deal with it! We should be able to just raise the portion of our yards to the height of the foundation, but with smoother sloping sides! 🙂 (But if you make the slope steep it won't be able to be covered with grass 😕 -- but I don't know if we will able to use the spray paint terrain covers on the sloped sides or not. 🤔  My guess is that we will. 🤞  But I agree that the current foundation height issue is annoying! 😞

I just hope that @Nimbindi finds a solution to at least one (but preferably both) of their problems! 😉

@PugLove888   That is definitely good news! I remember using the Terrain Tools in Sims 2 (and possibly Sims 1). Sims 3 never stuck with me so I didn't get as far as working on terrain. Ya, the rooms thing when all things must match per foundation or wall height is probably no fun for some folks who download some of the greenhouses I made. Some are a building that would have to be placed before your home or it will place instead of your existing building, I assume. That's how I place them when using them with a new house build when I use them. Otherwise you just need the greenhouse or plant rooms. I have gone so far as to, when I wasn't positive I had enough yard or building room space to place a room without destroying anything, to go 2 layers down (two basement levels, since I occasionally have issues when only going one level down for this, and making a room there bigger than the room I'm placing and with extra tall walls if there are trees in the room (greenhouses) then placing the new room there and bringing the items up one at a time to the yard or home area that I want them. Gotta do what works, and be creative often, with sims. 

Anyway, the Terrain Tools will be very helpful for your situation @Nimbindi , once they come out. I suppose, as @PugLove888 said, you can just do something temporarily until then. They should provide you a lot more versatility if they are like the old ones and allow you to raise and lower terrain to fit your needs, for example. So, @PugLove888 - do you just need to raise the ground where the room or item will be placed/built to the height that would match the house (in other words raise the ground the amount of height the foundation has added to the home) then the foundation will not automatically be added to the 'room', gazebo, greenhouse, etc., that you are placing in the yard? Do you happen to know if there's a video or information about this upcoming release that we could also view? 

@SheriGR, sorry I’m late in replying – my computer froze up for some reason last night when I was trying to reply, so I had to postpone it.  (My computer made me feel like I was playing The Sims 3 it was so slow! 😪 )

It sounds like you go through an ordeal in making your greenhouses! 🤨  I hope the terrain tools help you in that aspect.  I'm very happy to be able to finally manipulate the terrain like we were able to do in TS3 & TS2!  I'm not a big builder, but sometimes I do like to build, and/or give my landscapes some distinctive touches.  And of course, even people who never build their own houses in TS4 will still benefit from the terrain tools since it will affect what's listed in the Gallery by people who love to build! 

I don’t know the extent of the terrain tools, so they could be exactly like the ones in the past, but they could also be somewhat different. 🤔  My guess is that when using an outdoor “room” on a house with a foundation, you will still get a raised land platform under the room, but with the terrain tools I think you should be able to lower that platform so it is more level with the rest of the backyard, or at the very least you should be able to slope and smooth the edges so they look like a natural rise in the land (and you shouldn’t have to add stairs either! 😃  )

Here is a link to the footage for the terrain tools from the developers’ livestream.  They are planning on having one every month to update us on news regarding TS4 and other games like the mobile ones (Sims Freeplay and Sims Mobile). It's called "Maxis Monthly" and will be on the Twitch TV site. 🙂 The first half of the video is only about what’s new with the mobile games, so starting about halfway through they get to the new TS4 stuff.  There also will be a new career for free in this update! 🥳

https://www.twitch.tv/videos/317544173

Happy Simming! ❤️

@PugLove888 Sorry about the computer freeze-up! Computers can make you nuts sometimes, huh? Well, no worries... adding my greenhouses or other things isn't difficult... that is just a technique I have been using to get items out of a room and into the build when I have no open space to plunk a room into. It's not actually difficult. Other methods of doing so would be more difficult (when I have no space to put the room but I want the contents). 

I appreciate the details on the terrain tools. I'm looking forward to this for sure!

Thank you so much for the link to 'Maxis Monthly' ! I haven' t seen that before and look forward to checking it out! 🙂

@SheriGR, I just realized that there will be another Developer's Livestream explaining the upcoming update in more detail in about 12 hours from now as I'm posting. 🙂 It will be Thursday, October 11, at 11:00 AM Pacific Time!  But if you can't watch it live (where you will be able to ask questions live) you can still watch it afterwards! 😎  This might answer more of your questions. 😇

@Nimbindi, you might want to watch this too, since it will probably help with your current terrain problem! 😉

@PugLove888 I watched the livestream today - the demo of the terrain tools... Wow! Exciting stuff! I sure hope it comes with some bigger lots to accommodate the dynamics of varied terrain on a lot.Thanks for the heads-up! 🙂

I took a screenshot of the problem but I have no clue where it is saved so I can't attach it here. The pool was surrounded with stone. The walkway made a straight line to the pool except for the last row of squares. So, what I have is a walkway that does not connect to the walkway surrounding the pool. Four squares of grass separate it. When I try to replace those four squares of grass with walkway tiles, it replaces the grass, but it will also replace one or more tiles of the walkway. So I am unable to connect them. Because it keeps replacing a tile fo walkway with grass. Basically moving the grass tiles instead of replacing them