Wrapping the wall with plastic
I was very happy to find your site and hope you are able to help me with this question. We covered the side and back of the house with stucco 30 years ago. The finish wore thin and am having it recoated with a Portland, Black, Red, Brown cement, lime, sand, Acryl 60 mix. Before this mix is placed on the walls, the mason brushed on Plaster Weld, to help ensure that the new mix adheres to the old job. Tuesday, the last section was troweled on to the walls there was only about 4 hours before heavy rains poured down.
I covered the walls with plastic, but water still ran down from the roof and was able to soak the walls. I took off the plastic last night and I looked at the wall this morning. I was able to see a couple of cracks and it seems that the lime surfaced causing a white coating over the area or portions of the area just done. Should I be concerned about this section not adhering, future cracks, etc? The color also seems to be lighter than the other sections. Is this due to the rain or the white bleed through or something else?
The contractor said he is going to wash down the entire job after he is done with acid, grind out any cracks and fill them with the same mix. Because of the rain is this section weaker? The back portion of the house came up with a few hairline cracks. The day this section was done it was in the 80's. The answer to these questions and any other advice is greatly appreciated. If you need more information let me know.
Wrapping the wall with plastic when the finish coat is freshly put on will leave white splothes on the wall. if the plastic contacts the wall. When covering a wall with plastic to protect a fresh color coat from the rain, it is important to make a tent, for example, nailing the plastic to the facsia board and pulling the plastic over the top section of scaffold. Another example is for columns or chimneys the plastic needs to be stretched out like a tent, weighting down the four corners of the plastic.
It is a good idea in cold weather to leave the wall covered two or three days. The finish sets slower, and may take days to set up. Meanwhile, if it rains the wall can get messed up.
An unexpected rain storm hit us the other day when we brown coated this chimney. This quick correx "roof" saved the mortar without contacting the work.
If the white splotches aren't too bad, you may try my mystic secret of water seal. Here's a link to the mystic secret of water seal.
If the wall is real bad, you may want to re-coat the whole wall. It is important the mortar has acrylic bonding admixture. We always mix the admixture half and half with water and mix the mortar with this mixture. With color cement mortar, the color is too white. Another mystic secret is to add 25% more color to the mix. Here's a link to the mystic secret of adding 25% more color.
I hope you didn't paint the wall with plaster weld, but used weld crete. Plaster weld will fail if it gets wet or used outside. This could create a larger problem. I like bonding admixtures so much better than weld crete.
Thanks for writing. I hope this helps.