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concrete against stucco siding?

1500 Views 6 Replies 7 Participants Last post by  Racinmason
No responses previously, so I'll simplify the question...

A new porch will butt up against the house. Can I pour up against the existing stucco (maybe with an expansion joint?) or would you trim back the stucco? If so, what type of underlayment?

Thanks!
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I have this same question and can’t find a clear answer. Some say absolutely not, some say expansion joint, some say waterproofing, some say saw it out and run concrete under the stucco. we would like to walk out of our house without a large step down to a patio, Right now our door sill is about 16” above grade, and we want to pour concrete just 2” lower than the door so it is wheel chair friendly. This would cover 8-10 inches of our stucco wall, 6” of which would be above the foundation. Back fill & Concrete to stucco to foam to sheathing to framing. Phoenix, Az. I see all sorts of issues… my husband says it’s fine, don’t worry… what say you?
Maybe post your question in the “concrete/masonry” sub-section.

I don’t have any technical expertise regarding your question, however what you describe does not seem to be doing it the right way. Will it work? Probably. Will it last???

perhaps post a few pictures
I have this same question and can’t find a clear answer. Some say absolutely not, some say expansion joint, some say waterproofing, some say saw it out and run concrete under the stucco. we would like to walk out of our house without a large step down to a patio, Right now our door sill is about 16” above grade, and we want to pour concrete just 2” lower than the door so it is wheel chair friendly. This would cover 8-10 inches of our stucco wall, 6” of which would be above the foundation. Back fill & Concrete to stucco to foam to sheathing to framing. Phoenix, Az. I see all sorts of issues… my husband says it’s fine, don’t worry… what say you?
I'll do my best here....

By the book or in new construction the stucco would stop about a half inch above where you would have the top of your concrete. The stucco contractor would have a termination strip there. A termination strip is like a drain, if any water gets in up above in the stucco... than that let's the water get out. Also, before the house was stucco'ed, a waterproofing would have been applied behind the concrete area protecting the wood. The waterproofing behind the stucco and the concrete would be a system that works together.

That being said, your house may be older and not have a lot of these systems. Retro fitting might not be an easy thing here. What I have seen, and many times I might add, is this is often ignored and the results seem to be fine.

If care is taken and caulking is added at key points then little to nothing will need to be done.

It's just not the preferred way.

Pictures of your stoop area might help.
The answer is no, the stucco has a drain pane behind it and needs to drain, you block that and you are causing a problem that nearly always causes rot behind the stucco.
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I can not fathom a situation where concrete above the top of the stem wall would be a good idea.
Outside is even a worse idea. Stucco is not a completely water proof surface. If you look around your home you will find a drip edge at the bottom of the stucco.
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Is this for a new concrete pad under the porch, out of the weather? Will this pad float or be on a foundation? More info or a pic on this end will definitely help, other than that, everyone is speculating, until then you'll get every answer imaginable.
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