Posted: 6/9/2011 6:45:54 AM EDT
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The house we just bought has a wood porch sitting on top of a concrete pad. The pad measures roughly 8'x8'. With settling, the pad now slopes slightly toward the house. It's minor, but it's noticeable.
We want the porch redone. Instead of having the existing pad removed, can an extra layer of concrete be poured on top to correct the slope issue? |
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The pad is settling because the ground underneath it wasn't properly compacted, it will more than likely continue to settle unless you dig it up and repack the dirt. That being said, why don't you level the porch instead of the pad( i.e. shim the legs to level it)? If you are removing/replacing the porch and the pad will be accessible either plan on reworking it for the long term, or planning on shimming the new porch every so often in the short term. If you pour over it the new layer will eventually settle as well. Additionally, the settling will probably continue apace as water being directed towards the foundation leaks into the soil under the side of the pad that's sinking. Any dirt or concrete by the house should fall away from the foundation so it doesn't funnel water up against the house. eta: the legs of the porch should be sitting on blocks/pedestals made for that purpose anyway so they stay dry. |
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Quoted: I think you can have cement pumped under the pad under high pressure, which will lift it. I have seen it on home improvement shows, but have no personal experience. I got the impression it was not that big of a deal or unique. Just something to check out. My .02 Mud Jacking. Most places that do it will come give you free quotes and guarantee the work for some time...check your local yellowpages. Speed |
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Quoted:
I think you can have cement pumped under the pad under high pressure, which will lift it. I have seen it on home improvement shows, but have no personal experience. I got the impression it was not that big of a deal or unique. Just something to check out. My .02 There is a company around here that advertises that service all the time on TV. |
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Quoted:
The pad is settling because the ground underneath it wasn't properly compacted, it will more than likely continue to settle unless you dig it up and repack the dirt. That being said, why don't you level the porch instead of the pad( i.e. shim the legs to level it)? If you are removing/replacing the porch and the pad will be accessible either plan on reworking it for the long term, or planning on shimming the new porch every so often in the short term. If you pour over it the new layer will eventually settle as well. Additionally, the settling will probably continue apace as water being directed towards the foundation leaks into the soil under the side of the pad that's sinking. Any dirt or concrete by the house should fall away from the foundation so it doesn't funnel water up against the house. The porch doesn't completely rest on the pad so the slope of it isn't as drastic, at least not the top anyway. We want to re-do the porch not because of the slope, just because it's kinda crappy. The pad was poured ~6 years ago when the house was built. I know I want the slope issue corrected as you mentioned as I don't want that water pooling up there. I already had a small leak due to a downspout that emptied right against the foundation. A 3' extension on the spout and some dirt to fill the hole that was there fixed that. |
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One of the companies I work for is a concrete company. I just talked to my concrete expert and this is what he told me.
You can pour concrete on top but if you have a slope you will need to drill into the old concrete and put in some small rebar before you pour the new concrete. Another suggestion is to drill into the foundation just a little (Like 3 inches) and put in some rebar going into the foundation through existing concrete. All of this is to keep the top piece from sliding. One other thing you can do is dig a trench at the toe of the slope and put a trench measuring six inch wide and six inch deep so when you pour this trench will fill up and add more stability. If you cannot drill you can also break up the old concrete with a sledge hammer and it would do the same thing. But drilling is much better. Another thing you can do is make you pad 9X9 or 10X10. You will end up pouring over the sides of the existing pad and this will provide the best stability and prevent movement. Using this method plus adding a little rebar would be your best bet. |
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Quoted:
Quoted:
I think you can have cement pumped under the pad under high pressure, which will lift it. I have seen it on home improvement shows, but have no personal experience. I got the impression it was not that big of a deal or unique. Just something to check out. My .02 Mud Jacking. Most places that do it will come give you free quotes and guarantee the work for some time...check your local yellowpages. Only places I can find are 70 miles away. It sucks living in BFE. |
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Quoted:
One of the companies I work for is a concrete company. I just talked to my concrete expert and this is what he told me. You can pour concrete on top but if you have a slope you will need to drill into the old concrete and put in some small rebar before you pour the new concrete. Another suggestion is to drill into the foundation just a little (Like 3 inches) and put in some rebar going into the foundation through existing concrete. All of this is to keep the top piece from sliding. One other thing you can do is dig a trench at the toe of the slope and put a trench measuring six inch wide and six inch deep so when you pour this trench will fill up and add more stability. If you cannot drill you can also break up the old concrete with a sledge hammer and it would do the same thing. But drilling is much better. Another thing you can do is make you pad 9X9 or 10X10. You will end up pouring over the sides of the existing pad and this will provide the best stability and prevent movement. Using this method plus adding a little rebar would be your best bet. Interesting ideas that I can talk about with the contractors. Thank you! |
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Quoted:
The pad is settling because the ground underneath it wasn't properly compacted, it will more than likely continue to settle unless you dig it up and repack the dirt. That being said, why don't you level the porch instead of the pad( i.e. shim the legs to level it)? If you are removing/replacing the porch and the pad will be accessible either plan on reworking it for the long term, or planning on shimming the new porch every so often in the short term. If you pour over it the new layer will eventually settle as well. Additionally, the settling will probably continue apace as water being directed towards the foundation leaks into the soil under the side of the pad that's sinking. Any dirt or concrete by the house should fall away from the foundation so it doesn't funnel water up against the house. eta: the legs of the porch should be sitting on blocks/pedestals made for that purpose anyway so they stay dry. This is true. You might have to break up old concrete remove old dirt replace with new processed compacted dirt. This will depend on the soil conditions of your area. A mix of sand and clay is really good. Remember that if you do this make sure you have processed dirt outside of the pad by at least a foot. I also work for a dirt company! 
But if you cannot or dont want to do this look at my other post. |
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I need to clarify some things so there is no confusion about my previous posts.
You really have these options. 1. You can perform what we would call a Sub Ex. That would include removing the old concrete and digging up the soil around ten feet deep and at least one foot outside of the pad although five feet is the standard in the dirt business (All of this would depend on soil conditions) replacing old dirt with new processed material, then you moisture condition and compact the material in place then pour new concrete on top of processed material. The bad thing about this option is they have to be really carful compacting the new material because they can damage the foundation. It is also very expensive. Very expensive. You will have to pay for the demo, importing and processing new material and compacting said material and pour your new concrete pad. If you do this make sure you have a reputable dirt company perform this work. A good company can do this without a problem. A bad company will destroy your foundation. Please note: see counter fort below 2. As others have said you can also call a mudjacking company and they will place supports on the pad remove the old material and replace it. This will allow you to keep the existing pad. If you are going to remove the soil this would be your best and cheapest option. This still is expensive 3. Have a counter fort installed. This is a support that comes from the foundation of the house and connects to a new concrete pad. To do this you would have to sub ex. You can talk to a mudjacking company to see if they can install one of these but I am not sure if they can. This option can also be expensive but it is the best. 4.. Say fuck it and just pour over the existing pad. The problem with this option is that you might end up with the same problem you had before but it is the cheapest option. Especially if you are going too sell in the future. It might take years for the new pad to sink ( Again this will depend on soil conditions ). The reason I suggested #4 was because you asked specifically about pouring over old concrete and it is the cheapest option available to you. But it does come with risk. If you had a lot of money I would suggest option 1 and add a counter fort. If you had some money to spend and wanted a long term option. Mudjacking will work. If you had very little money to work with I would go with the fuck it option. |
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Quoted:
One of the companies I work for is a concrete company. I just talked to my concrete expert and this is what he told me. You can pour concrete on top but if you have a slope you will need to drill into the old concrete and put in some small rebar before you pour the new concrete. Another suggestion is to drill into the foundation just a little (Like 3 inches) and put in some rebar going into the foundation through existing concrete. All of this is to keep the top piece from sliding. One other thing you can do is dig a trench at the toe of the slope and put a trench measuring six inch wide and six inch deep so when you pour this trench will fill up and add more stability. If you cannot drill you can also break up the old concrete with a sledge hammer and it would do the same thing. But drilling is much better. Another thing you can do is make you pad 9X9 or 10X10. You will end up pouring over the sides of the existing pad and this will provide the best stability and prevent movement. Using this method plus adding a little rebar would be your best bet. I'd recommend removing the old. I think over-pouring might work but my problem has been that old concrete will just slightly settle below the new and leave you with perfect ant/insect habitat between the two slabs. Best to remove it and you might want to consider making the edges a fair bit deeper to prevent insects and rodents from getting below the slab. |
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just shim it and be done with it. Buld the deck with the out of level in mind and cut your supports accordingly. If it sinks in the future you can shore it up and shim it to keep it level.
Or you can tear down the slab, compact the ground using an aggregate, then tie in rebar into the exisiting structure and then form and pour a new slab. which one do you think is easier/cheaper? the proper way to fix it has already been mentioned, this is more the "Git R Dun" way. 
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Adding concrete on concrete that is on pour sub-grade = bad idea.
Additional weight of new concrete will cause some additional settling However it will get the water running the right way. Mudjacking - sometimes works very well sometimes doesn't work at all, grout ends up in places you didn't know would allow grout in (unknown cracks or holes) sometimes it seems to work, but causes other problems Take the slab out. Grade subgrade and compact subgrade - re-pour slab |
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Quoted: Quoted: The pad is settling because the ground underneath it wasn't properly compacted Untrue. http://www.remotecentral.com/dvd/tremors3-2.jpg OP has worms, and he'd better do something about 'em, pronto. Those are Graboids. They should turn into Screechers in less than a month. Look out for the Ass Blasters though. |