sdello, yes we are on landfill and in 1990 post-tension slab was the thing to do in this area. What does that mean that the slab should be supported on grade beams? Do you mean they should dig up around the foundation (now that would be an expensive job as it is pretty much cement all the way around the house) and put some sort of pilings into the soil? We are not the original owners, but are the first people to live there. The original owners bought on spec to make a profit. The first year the builder would calk things, but then they moved on to their next development and then went out of business under that name. I would say that for the most part all these cracks have been there at least 10 of the 15 years in varying degrees. I used to caulk the ones I could reach, but never touched the cracks where the walls meet the ceiling. Funny thing, until I started wearing my glasses at home, I never even noticed them, but with my glasses everything came into focus. :-\ Some of the patches they originally did have held up the last 12 years or so. Some just kept spreading. I think made a mistake installing plantation sutters on all the windows before the settling stopped or at least slowed down as both sides of the house have sticking problems with the shutters. That was putting pressure on the opening. From the very beginning there was not a straight wall in the entire house and wall sections from top to bottom weren't even the same measurement, meaning left to right. We pretty much have patio surrounding 3 sides of the house, no contact with dirt, and then one section of the front is the driveway/garage, next to that is a planterbox area and then next to that is the frontdoor. I'd say the only sections that are exposed to dirt would be a section of the living room that is about 6'. I'd say it has probably been at a slow rate, but just never paid a whole lot of attention to it until I realized the amount of money we were spending for remodeling two bathrooms, kitchen and laundry room, also carpeting and whole interior painting. We have never painted the interior for the whole 15 years. Just minor touchups where I caulked or where there was a little wear and tear. The windows all operate, though both sides of the house, a couple windows are definitely out of square. Of course, they were like that when we moved in at 1 year old. I had the builder redo the one window, but didn't check it right away, but found that he didn't really do a great job replacing it level anyway. I'd say the areas where I patched myself, and didn't do the job right, just adding caulking and painting over it, some held up ok, others just kept reappearing after a few months or year. This was supposed to be our "forever home", so we are really upset that there might be a problem. We are hoping that this is just part of the pain of living on landfill and that there is no major problem. Can't afford to do repairs and remodel and the kitchens and bathrooms...

I didn't understand a single thing about "right,left horizonal,vertical"and on and on but here's some answeres in general. - What is the best way to fix it? How much will it cost?( You will need somone on site to tell you) - would this crack affect the house foundation in any way in the future?(Not likly,especially if the patio cracked away from house foundation) When and if you demo and repour patio,put an expansion joint between house and patio slabs. - can this crack be fixed by filling and sealing? (Not perminatly) - can this crack be stopped from further movement?(Not likly unless you install piers and/or footings beneath it. Another option is demo slab and repour a new one with proper footings and steel. - is it safe to convert the sunroom to office or it will cause more cracking?(I don't think normal weight of addition will cause any more movment than will ocur anyhow. I wouldn't reccomend adding improvements on the slab. I would leave it as is and put the addition elaewhere or replace the slab before building on it. Bottom line,you will need a pro with eyes on to get best reccomendations. Good luck with it.

Those are naturally occurring fissures. As long as the top is properly supported these will be no issues.

Thanks everyone! I won't be able to do this until Fall, since I have a huge waterlily growing in it. The crack is small and the leakage is minimal so far. I'll keep my eye on it and if it gets worse, I guess I'll have to figure out what to do with this huge waterlily (and the million tadpoles that live in the tank). If I can wait until later Fall, after the stocktank is drained, would it be better to do it early next spring, so it doesn't live through winter first? I wonder what causes these cracks.....might it be manipulating this big stocktank to turn it over in winter and then back up again in spring........or could it be a slight unevenness when it's full? I'm sure the sun is hard on it too. I have 2 in-ground 300 gallon stocktanks and (knock on wood), they've been leak-free for at least 15 years. But that's probably because of never being moved or exposed to the sun. I'm going to print off all your suggestions so I have easy access to them when the time comes. I really appreciate everyone's suggestions!