Replies

1. 
   Train_Driver_Chris | Feb 08, 2001 11:34pm | #1

   *
   What about slab jacking the existing patio. Basically a sand/cement grout mixture is injected at low pressure into 2" holes strategically placed thru the slab to raise the slab to more suitable location, then the holes are filled and troweled. If the slab is not structurally fractured already, this can be an option. Have to hire a contractor specifically outfitted for this though.

   TDC

1. 
   Jim_K_ | Feb 09, 2001 12:36am | #2

   *Look up "polymer overlay" in a search engine. These products can create a strong, thin topping (>5000 psi and 3/8" or so). Perhaps one of the suppliers can advise you on the way to build up to the 1.5" you need at the one edge.

1. 
   Heck_ | Feb 09, 2001 12:50am | #3

   *Thanks for the reply,TDC...I didn't mention that the slab edge is tied to the house(an ICF home) with rebar and that it has also cracked in several places.We have a high clay content here and that has contributed to this patio problem..I'm not sure if the home subsided or the watered lawn adjacent to the patio swelled and raised the outer edge and cracked the patio...??Anyway, slab-jacking probably is not an option.

1. 
   Jason | Feb 09, 2001 01:05am | #4

   *Ever since I posted a message about six months ago on "Waterproofing a Porch", I've been experiementing, with good results (and I've gotten a lot of new business). I've had fairly good results with custom making my own screed boards on a tablesaw to compensate for the back "tilt" of a porch or slab, and then adding the correct fall. With these, I've done a pretty good job at using a sand topping mix to overlay the old. I've also been investigating Mapei and Ardex overlay products, but have not had the chance to get to a big enough city that would have the products. So far, my results have been good (no leaks, no standing water, no cracking, etc.), and the customers are very happy they didn't have to rebuild. Both Mapei and Ardex are on the web; just use the http://www.com surrounding their names. Hope this helps.

1. 
   Heck_ | Feb 09, 2001 01:44am | #5

   *Jim and Jason-Thanks for your responses....I have been researching various sorts of toppings-polymers,epoxies,everything I could think of that might work.As you are probably aware,the problem is finding a product that can do so many things...be stiff enough and have enough body to build up to 1.5" on one side and be able to be very thin but very strong on the other.I need something that would adhere to the existing slab,but would resist cracking if the slab moves again.I'm concerned that a sand topping mix,even with additives,would crack and break at the thinner section.I will check out the products you mentioned,in case I missed them.

2. 
   Ralph_Wicklund | Feb 09, 2001 02:27am | #6

   *Here's another to check out. FHB advertiser, too.http://www.abatron.com/home004.htm

3. 
   mark_holbrook | Feb 12, 2001 02:36am | #7

   *I'd bust the sucker up and put a new one in. It probably has a bad base under it, and its 5' big (25sf?) so its no big deal. No topping will work for long on this patio. A new one seems the best choice to me. You wont be going back on a new slab, but you will on a patch.

4. 
   Heck_ | Feb 12, 2001 04:33pm | #8

   *Thanks Mark-I have about come to the same conclusion...sometimes I have to do things more than once to get it right!The patio is actually 5' wide by about 50' long and makes a 90 degree turn inside an "L" in the building.It seems I have more trouble with concrete than with anything else...Wishing I had a good concrete sub and resigned to the tear-out...Thanks to all, James

2. 
   Heck_ | Feb 12, 2001 04:33pm | #9

   *
   I have a client with a 5' concrete patio, and the patio after settling now slopes back toward the house. Is there a way to pour a topping over the existing slab instead of tearing it out and starting over?
   I can come up about 1.5" at the house,topping would only be about 1/2" thick at the outer edge of the slab. This would give enough pitch to drain water away from the house and would be less of a mess for the home owner-however,I have been unable to identify a product that will work as a durable topping, especially at 1/2" thickness. Do I have no choice but to remove the existing slab and start over?