We are having a patio poured against the house, do we need to have any special barrier between the house and the new concrete being poured. It will also continue along an rv area. Will we need expansion board, or nothing. Also one concrete guy mentioned a new rubber (instead of expansion board) that has come out on the market, anyone know anything about it?
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Replies
My FIl's 25 YO house had the front sidewalk poured against the hous and now there is 1" of rot above the SW. I will be cutting a section out so there can be drainage/ venting before I replace the sideing.
If you go with a close pour be sure to consider what is going to happen to all the moisture that will be cought between the house and the sponge (concrete)
SamT
"Law reflects, but in no sense determines the moral worth of a society.... The better the society, the less law there will be. In Heaven, there will be no law, and the lion will lie down with the lamb.... The worse the society, the more law there will be. In Hell, there will be nothing but law, and due process will be meticulously observed."
Grant Gilmore, The Ages of American Law (New Haven: Yale University Press, 1977), pp. 110-111.
From 32866.117
Do everything possible to avoid putting the concrete against any wood of the house. You will almost certainly have rot and/or insect problems if you do. If you must do it, try to install some serious flashing between the wood and concrete, such as ice and water barrier protected by aluminum that goes well below any wood and up under the siding.
Al Mollitor, Sharon MA
We have a 10 year old patio that was poured up against our brick facade. Since the slab settled, and our house didn't, there are huge cracks all along the points where they meet. Apparently, this was the second attempt by the PHOs to make a patio. Nothing like tearing up a mistake made of thick concrete. ;o)
I can't think of any cons to not pouring it against the house, so I'd say put something in between if at all possible.
Even out here in the desert we have the same mosture problems. We always separate a new slab by about 1 foot to 2 and dig a trench between the two and pour in gravel like a french drain. But of course you can't always move the slab that far away, especially a porch. I would have a go with the rubber idea
jason
The two problems have been mentioned in various ways.
One is settlement or heaving. If it settles, it mostlyjust damages the slab, but if it heaves, it will tear up the connection to the house.
The greater problem is moisture, even in a desert. The concrete will often be cooler than surronding air and provide a place for condensation to happen. The concrete will also wick up water from the ground if no vapor bar is placed under when it is poured.
Obviously, keeping a wood surface wet is a good way to develope rot or to grow a colony of mold. Codes require that anytime wood comes into contact with concrete, it must be redwood or treated. better to barrier it with flashing, rubber membrane, expansion board, or Vycor.
Excellence is its own reward!
We have no wood against the house where the concrete will be poured. I think the contracter will be drilling rebar into the house before they pour the concrete. I guess it would be good to put alot of water on the soil before they do the job, so that it is settles better.
Pouring water on dirt is not compaction. Your need a proper subase for the slab. Tying the slab to the house with rebar is asking for trouble. Place filler material and pour an independent slab....that's not a mistake, it's rustic
I guess it would be good to put alot of water on the soil before they do the job, so that it is settles better.
No!!!
SamT
"Law reflects, but in no sense determines the moral worth of a society.... The better the society, the less law there will be. In Heaven, there will be no law, and the lion will lie down with the lamb.... The worse the society, the more law there will be. In Hell, there will be nothing but law, and due process will be meticulously observed."
Grant Gilmore, The Ages of American Law (New Haven: Yale University Press, 1977), pp. 110-111.From 32866.117