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I may have already found the cause (or not) for stucco to be expanding in strange formations (looks like ringworm or other nasty skin diseases) at various heights above ground level (0 to 5 ft.). I’d like to ask your opinion(s) and solutions.
The house was built in 1913,Praire style, is (was) brick until all was covered with stucco in, I think, the late 40’s. It had been converted to a hospital and when the hospital addition of CMU’s was removed the owner at the time decided it was too much trouble or expense to repair the original brick and just covered it ALL up. Do you suppose that when the stucco was applied and the weep holes for the brick were covered over that the capillary action began and kept the brick and mortar wet enough to finally cause the spalling and efflorescence that is now occurring? And, if so, is there a fix, such as drilling around the foundation, to make new weep holes? A note: part of the house has a basement and there is water seepage along cracks in the floor and part of the house has a crawl space and some of the brick foundation above ground level appears to be slightly damp. Thanks, Ralph
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New messages came so hot and heavy just after I posted this question about possible capillary action between stucco and brick that it got lost. Has anyone a clue if I'm on the right track and can find a fix? Thanks, Ralph
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As I read your message (correct me if I am wrong): This was a brick building exterior that was covered in the 1940's with CMU's? (Concrete Masonry Units??) You may need to explain that further to me.
Anyhow, if the brick was covered with stucco or some type of material was bonded to the brick backe in the forties.....latices(synthetic rubbers, aka latex) was just being introduced as a "perfect bonding additive" to cement based plasters. Originally, brick construction, of both vitreous and non-vitreous construction was common. Weep holes(actually cotton rope) was routinely placed in the mortar joints to wick the moisture that would build up via condensation(due to lack of insulation) to the exterior.
I am sure someone else on this forumn with more experience and "current experience" could comment on both the effects of moisture wicking to the exterior and the effects that moisture behind these "new synthetic rubber compounds" and "effloresecence", actually soluable salts AND the difference between laticee bleed and ..........well you get the drift?
Soluble salts can be deposited on surfaces when alkiline water(such as from landscape sprinklers) is allowed to hit masonry surfaces. Let me guess? Southern California?
Efflourescence from a cementicious mix will usually peter out within 1-5 years of placement.
Latex bleeding CAN occur 50 years later if all of a sudden hydrostatic pressure is allowed to saturate and force the latices out of the stucco, brick mortar or layer of bonding mortar. Especially if the weep rope from the air space behind the brick to the atmosphere was compromised. This would allow moisture to build up(hydrostatic pressure) in the stucco. The path of least resistance would either be the interior of the building or the "voids" in the stucco. Whenever you trowel plaster on a wall, it is extremely difficult to achieve a monolithic structure free of voids.
My advice: Chip off a couple of those "ringworms", gather a sample of the landscape irrigation water and take them to an Environmental Testing Lab for analysis. Call them before hand. Inform them of the situation. Inform them of what you(I) suspect and they will supply you with the proper containers(may be several w/stabilization chemicals). There is normally a charge for each chemical/compound they test for. Usually $5-15.00 per test. Environmental laboratories employ chemical engineers(at least in Ohio) and would probably welcome a visit from someone with a situation such as yours. These folks are as bored as medical lab technicians who anylize piss samples day in and day out.
btw: go in early in the morning and bring a couple dozen doughnuts. {grin}
ps: make it very clear to the lab that any water samples you submit ARE NOT an evaluation of WATER FOR CONSUMPTION. The method of evaluation and the costs differ greatly.
And keep us informed, SBR, alkiline sprinkler water of weep rope, or who can guess what? I do know from personal experience that these synthetic bonding agents/plasticisers added to cementicious materials and inert fillers were intended to form a very strong polymer chain. So strong as to be considered invincible to specific conditions of moisture and temperature extremes BUT highly affected by hydration, curing temperatures(and humidity levels during initial curing process) as well as the compatibility of the ingredients.
Ask for no more explanation, I am not the chemist or the chemist's son, but I will have combined the chemistry until the chemist's son comes.
Jeff
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Ralph, In my experience any building of this age that used brick would not have used double wythe walls, air space, therefore, I would say that there are no weep holes to be plugged.
You say that you have a slight moisture problem in the basement. I think this problem you describe might have more to do w/ interior moisture (vapor) penetrating the wall and condensing on the interior side of the stucco or sheathing or what have you.
You might have to take down part of the surface to investigate this. Check the archives here for other related topics under "vapor barriers," and "moisture diffusion."
Phil
*Thanks for the responses.The house is located in Jacksonville FL. The basic structure is frame with 1X diagonal sheathing then single layer brick, then a stucco-like material. The problem is also occurring inside the house on a rather massive wall corner that used to be the junction of the side and rear exterior walls but is now a 10 foot wide entry to an added sunroom. The porte cochere support columns which have no connection to the main structure, other than being on the far side of a 10 foot wide wrap-around tile floored and mostly unroofed veranda, are swelling up in places. No migrating moisture from inside the house there. I saw an old picture of the place as it was before the stucco job. Maybe if we wait long enough this butterfly could shed its stucco cocoon and be out in all its former glory. If I could figure out how to convert my scanner output to .jpg files I could send a picture. Thanks, Ralph
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I may have already found the cause (or not) for stucco to be expanding in strange formations (looks like ringworm or other nasty skin diseases) at various heights above ground level (0 to 5 ft.). I'd like to ask your opinion(s) and solutions.
The house was built in 1913,Praire style, is (was) brick until all was covered with stucco in, I think, the late 40's. It had been converted to a hospital and when the hospital addition of CMU's was removed the owner at the time decided it was too much trouble or expense to repair the original brick and just covered it ALL up. Do you suppose that when the stucco was applied and the weep holes for the brick were covered over that the capillary action began and kept the brick and mortar wet enough to finally cause the spalling and efflorescence that is now occurring? And, if so, is there a fix, such as drilling around the foundation, to make new weep holes? A note: part of the house has a basement and there is water seepage along cracks in the floor and part of the house has a crawl space and some of the brick foundation above ground level appears to be slightly damp. Thanks, Ralph
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Stucco should not be continuous from walls to below grade. It is customary to terminate the bottom of stucco with a drip screed. This allows trapped moisture to drain and provides a capillary break to prevent wicking. The stucco could be removed to about 6" above grade, the screed installed and the stucco patched.