Matt,
Stucco is a material that is Cement-based , but has a bit of a different chemical make up. It is mixed with sand (I prefer a more course sand than most. It tends to be a much lighter weight than concrete.
The screen acts as a method of keeping the amount used minimal. I needs to be said that it WILL EXPAND AND CONTRACT WITH TEMPERATURE CHANGES!!!.
When used on houses, expansion joints are put in every 6 to 8 feet vertically, and 8 feet horizontally. Because of the distance vertically I have no concern for cracking that way, but know that it will have ‘fault lines’ vertically because of the horizontal expansion and contraction. Since this is expected, I leave an overlap at 45 degrees in places that are less visible, so when these joint do what nature makes them do, it does not damage the larger portions. I have layed heavy plastic in some of the joint areas of the longer sections so that the expansion and contraction will be more apt to slide rather than create cracks. Since none of these sections are more than 6 feet long and 2 feet tall, large cracks are not an issue.
Jon,
We are at 4375 feet above sea level, and although summer time temperature can get over 100 between noon and 5 PM, nights are in the 70’s. Winters are usually mild with lows at night in the teens at the worst, but less than a month of daytime temperatures below freezing. Usually it gets up in the 60’s in the afternoons.
Normal humidity levels are in the teens, this being more than 9 months of the year.
This seems mild but most standards, but the drastic temperature changes of sometimes more than 40 degrees require more consideration for expansion and contraction issues than other climates.
And one other consideration: a crack in a rock wall is quite natural, so controlling where it cracks is the best way to maintain a level of managability in this process.
Once it is cured it does need to be washed of several times before painting. This is due to the lime content which leaches to the surface when mosture is present. If not washed properly, paint will peel off in a matter of weeks. However, if it is cleaned well and a good quality latex paint is used, these expainsion joints and other problematic areas will simply let the paint go in a small area and flex without ever turning loose at all.
I have seen this process used on some pretty big ‘mountains’ that started as stacks of concrete blocks and ended up being huge waterfalls and the like. Very light weight, very fast construction and above all (this being my personal favorite) when installed over hard packed dirt, with steel rods in the ground for structural reasons, NO WEEDS OR GRASS TO DEAL WITH!!!
I have several areas that will be first poured as concrete planter boxes for lack of a better way to explain. These will be in mountain sides and such. Once cured the stucco mold process will cover the lower side of the hill. I can then plant sedum, dwarf trees, and not worry about growth that I just don’t want.
Hopefully I answered all of tyhe questions. I’ll post more as progress comes along
