I’m helping a friend solve some issues with his patio. Right now, it is a poured concrete slab that unfortunately slopes toward the house.It is about ten feet out from the house, and about 20 feet wide. He said it slopes about 2″ the wrong way, which to me means it is off by about 4″ altogether.
He would like to correct this by either:
pouring additional concrete on top of it
-or-
adding a layer of flagstone, either using sand or mortar to get the right slope.
I’m not sure which method would be best of the three, and how thick the new pour would have to be at a minimum. Would 2″ on the outside and 6″ by the house work or is the 2″ area too thin?
If he goes with stone, would you recommend using mortar or sand? It’s a freeze-thaw climate (Wisconsin).
At any rate, I hope to not remove the slab that is there. Save that much agony, right?
Maybe some stamped/stained concrete would be nice?
Other suggestions?
Thanks.
Replies
dawg... where ya beeeeen ?
hey, he's gotta correct the pitch of the slab .. or all the water will drain thru and follow the old slab back to the house...
could do it by regrading with gravel and then a 6 mil poly... but the chances are food of puddleing (sic )
how a bout a new top over slab and then lay his pavers on that ?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Would be easier to break out the sledge hammer and bust it out and start over. you could also rent a jackhammer for about 40 dollars a day (the jackhammer is more fun than the sledge.)
call one of the concrete leveling companies to come out. they will pump under the low end and raise it to the correct height. probably be cheaper to start over though..
Remove the existing slab! You are talking about a few hours here. I could bust that out and load it in an afternoon with a sledge. With my electric jackhammer it would bust out in about an hour. You will spend far more time, effort and money trying to avoid this simple job.
I would break it out and start over but your customer may think you're crazy when he hears how much the haul and dump charges are. You can't patch this one MAD Dog , how about buiding a deck over it! You don't even have to space the boards if you don't want to.............:-)
Bob
"Rather be a hammer than a nail"
Recently, I broke up a very heaved and cracked garage slab, the result of a severely leaky roof. Instead of breaking it into large chunks that'd have to be hauled off, I broke it into little bits that could be wetted and compacted and used as a base for the new slab that was to finish 3" higher in elevation than the old. Worked great!
Didn't take very long with a Bosch Brute, 1 day for a 20'x15' slab, but , no dump costs and no new material for base. Noticed a pic in FHB's "Foundations and Concrete Work" of recycled concrete used as base. Not any less work to do it this way, but quite a bit more sustainable due to decreased trucking.
Lance
Got me there P-D! That's a good memory, I'd forgotten about all that malarkey.
We did talk about the deck, but they would prefer a patio of stone or concrete, maybe even bricks.
Looks like everyone wants me to take that slab out. Don't tell me how simple it is, I've been busting concrete for 25 years. He also wants to remove and redo the concrete driveway so it's not like we won't get a chance anyway.
What about the option of mortaring vs sand in the stone phase?
I'm not sure how large an area we're talking here but the only section I would worry about in floating a new slab would be farthest from the house. I would rent a concrete cutter and just break out the high spot so you could get a full 4"pour. How deep would it be at the house?Could you put some of the broken concrete from the high side at the low side toward the house before you poured a new slab? That might save you a few yards of pour.
I'm not a brick layer but if I did a brick patio I would use sand over mortar because the mortar would break out from settling eventually.
I really like the new stamps for concrete they use today. Slate, cobblestone,brick.
If you are doing a driveway I would talk them into a complete package pour. Drive. sidewalk, and patio. Brick with Cobblestone edge really looks sharp..Bob
"Rather be a hammer than a nail"
About Mad Dog's sloped patio----don't think that the concept of drainage has been addressed well enough in the replies yet.
1. the option of a wood deck over the existing would level it just fine for customer satisfaction when walking on it.........but STILL something must be done about keeping a now-hidden slab from delivering water to the house/foundation etc. Also, the wood deck would need to slope away from the house but I figure Pro-Dek you know that---
2. the sand v.s. mortar issue same problem: sand may level the setting bed and yes it's more forgiving for cracking/settling, but drainage is still toward house through that medium, unless some kind of impermeable membrane is put up against house first--but I'd bet the joint would fail and water will seep towards house.
the post about worrying more about the far end of the slab makes sense in that in order to avoid going too tall overall, you are at risk of tapering the new layer of concrete to infinity and it will break up because it's too thin? Depends on how far the door sill is from the existing slab---& how high you have to go to get slope for drainage.......
Guess the advice for jacking it up or breaking it out is sounding better to me--I hate breaking up concrete! you guys that make it sound like a piece of cake really impress me...........
Lil'Acorn
hey---i'm doing a quick edit 'cause I just re-read the posts and figured out someone was being a joker suggesting the deck over ---that must be what the 'malarkey' comment was about; especially since the "you don't even have to space the boards" comment seems like a red herring........obviously a memory of an old job & a 'you had to be there' event.....So I know when to butt out and leave you guys to it. Never mind my jabber....... Lil'Acorn
Edited 4/10/2003 1:12:41 PM ET by Lil'Acorn1
If (when) you pour the new patio...do yourself a favor and at least look at the stamped concrete. I was standing on some the other day and it was really amazing...I've seen some that was very poor.
It's not inexpensive, too much for much budget and patio size, but it is really nice looking.