[Gardenscapes]

New to your forum. Very pleased I found it. I am a landscape designer but do not do installations. The more I learn about installation the easier it is to work with contractors and they appreciate that. Also helps me become a better designer.

I have a client who wants a raised patio of Courtyard Allan Block level with the sliding doors. See picture below. Problem I see is the stucco siding on the house. What kind of moisture barrier would work? Can it work? Or do you need to have breathing room between the stucco and the raised patio? Any suggestions from experienced practitioners is much appreciated. I have tried the Allan Block web site, but they are particularly silent on the subject.

[fakie99]

we do raised patios all the time - although it is typically against brick, not stucco. I will generally use a non-woven geotextile fabric between the brick and the gravel base of the patio. I really don't think that moisture is a problem, because base gravel is a fairly free-draining gravel. now, stucco will absorb more water than brick, so i think a vapor barrier/visqueen - possibly even alum. flashing - between the stucco and base gravel would be in order.

jim

[Stonehenge]

Gardenscapes, your concerns are valid. Stucco and the material it's attached to cannot withstand the compaction and pressure of a crushed stone base. A raised patio for a house like this (and most houses, for that matter) will need to be built like a freestanding unit independent of the house. That means retaining wall block along the side of the patio that would be "in contact" with the house.

The struggle with any kind of vapor barrier is, it might keep moisture out, but that also means it's keeping moisture in. So for that particular situation, I guess I'm riding the fence. Whether you use some type of barrier between patio and stucco, you should build the patio structure a fraction of an inch away from the stucco, but try to seal the points where patio separates from house to prevent that small gap from becoming a home for bugs.

[agla]

You talk to a contractor about cutting the stucco at the height that would allow a raised patio. It is, after all, another form of siding. If it were clapboard, wood shingles, or vinyl, you would also remove that before flashing and working against the house.

[Stonehenge]

We've never had to work against stucco, Agla - how would you suggest trimming that out to get a nice look?

[agla]

I never worked with it either. That is why I suggest talking to a contractor that is familiar with it. I'm a big fan of letting builders deal with the building and the landscapers taking it from there.

[skahuna]

I wouldnt remove the stucco to waterproof, at best your just going to find plywood under there and your seam will be a good place for a leak. I would put aluminum flashing over the stucco. If theres no rim joist or your concerned about damaging the wall during compaction put 2'' rigid foam to top of modified. its engineered for below grade and will distribute the weight of the patio.

[mark allen]

wow, talk about some intelligent answers, I found myseof agreeing with every post..... I ran into this with an aluminum siding house and they (and the builder) decided to do what stonehenge said..."to build a freestanding wall. My argument/point was that bricks are basically impermiable from surface water, so that's not the water to worry about...... If it were me...?..........man that's a tough one.... check more with builders and track down your Allan block rep. websites are only as good as the one who designed it......

[mark allen]

and another thing.... looking again at the picture, it looks like painted gray cedar trim around the windows......if that's the case can't you either build up to it or cut it out and put whatever barrier seal you desire and then trim it with painted gray cedar? Just a thought.

[PSUscaper]

what about just using foundation tar on it? I don't like the idea of aluminum flashing because.....how are you going to seal the top of it and not let moisture seap in behind it. On a siding house, you tuck the flashing up under neath the siding. Not here.

I would figure out the final height of the stoop and tar it about a inch below the height of the new patio.

It would be that or build the dummy wall along the backside, which is possibble, but a lot more work.

[Drafto]

When in doubt I would go for the freestanding wall against the house.

Pros:

1. you will NOT damage the house foundation/stucco/framing with compaction
2. in no way would you ever be responsible for future water damage due to cutting or damaging the moisture barrier currently in place
3. i believe in a raised patio application this is a stonger foundation then just simply terminating the walls at the house, it is similar to using deadman in a wood wall
4. if the only thing you have to worry about is creating a home for bugs then I would say this was a pretty safe decision


Cons:

1. a tad more expensive
2. explaning the extra cost to the homeowner that will never see the pretty block they paid for that is now buried

All of the above just reflects my thought process and opinions. The largest influence on the way I do things is future accountablilty, I would love to eliminate as much of that as possible.


Dan

[Gardenscapes]

Thank you to everyone that responded to this post. Very valuable information. I will be giving all the posts to my client. I did not know about the compaction problem against the house, so that was really informative. I like the free standing wall the best, built away from the stucco so that it can breathe. While I also agree with Agla about letting builders deal with the building and the landscapers taking it from there, I prefer to know while I’m in the design stage how it’s going to be built, that way I don’t design something that can’t be built or costs an arm & a leg. Just a note about stucco in my climate (which is very rainy). The reason I was concerned about building right against the stucco was due to our “leaky condo” disasters in my area. Thousands of condominium homeowners had to have their buildings stripped back to the interior walls due to moisture problems, visible leaks & mould. Extremely expensive.