Hi everyone . Thanks to all for the info I have read on stucco coatings. I'm leaning away from the cementous stucco and more to the Acrylic, more for speed and elastomeric properties as we are in a very seismic zone. I am looking for a good/high quality product that will withstand Heat, High humidity and mold. Probably not unlike Florida as I am told.  I'm searching for the right product that  will be long lasting , little maintenance.   Does anyone have experience with products in these conditions. Suggestions welcome.  I'm looking for inside coatings as well.
The other subject is roofing coatings, not flat roofing, low slope or a regular 4/12 pitch.  Is there anything out there that I can just put in the concrete or seal the concrete with to provide waterproofing, colour? , or do I have to put a tin or membrane over it ?
Thanks Randy

Posted By laclu on 16 Feb 2010 09:11 PM

Hi everyone . Thanks to all for the info I have read on stucco coatings. I'm leaning away from the cementous stucco and more to the Acrylic, more for speed and elastomeric properties as we are in a very seismic zone. I am looking for a good/high quality product that will withstand Heat, High humidity and mold. Probably not unlike Florida as I am told.  I'm searching for the right product that  will be long lasting , little maintenance.   Does anyone have experience with products in these conditions. Suggestions welcome.  I'm looking for inside coatings as well.
The other subject is roofing coatings, not flat roofing, low slope or a regular 4/12 pitch.  Is there anything out there that I can just put in the concrete or seal the concrete with to provide waterproofing, colour? , or do I have to put a tin or membrane over it ?
Thanks Randy

Randy;

yes I have much experience with elastomeric & acrylic stucco in Florida ....ALL BAD.  Use cemetitious stucco

concrete roof in seismic area ............. remember Haiti?

Gigacrete has a 3-4 mm product that will work on the interior. I would use this same material on the exterior as well but put an EIFS or TAFS finish coat over it for color and to give it additional protection from the humidity in CR. On the roof, there are many great products for sealing after the fact. If this were my house in CR, I would put something like Xypex in the concrete mix, then once the roof is complete, coat it with a product either from Euclid or Sonneborne, depending on what you want the roof to look like when finished. We'd be happy to discuss these as well as construct and apply. Where are you in CR?
[email protected]

Chris, What bad experiences have you had with ICF coatings?

What generic, simple name can we use to describe these coatings?

In Panama, something called M2 is used. It is foam and wire and gets covered with cemetitious stucco on both sides.

Most common - block/stucco walls (no wood), steel roof supports, sheet metal roofs with foil covered foam on the underside. But this means no wall insulation.

Hi Chris. Thanks for the info. I do remember Haiti.  I'm curious  about why acrylic stuccos don't work in these climates.

moisture underneath the coating is the problem, no dew can be present on substrate or coating will blister/peel, too long in sun and surface is too hot, so the window for application is narrowed to about 2-4 hours a day. (it is NEVER the mfg. fault, its always the application)
oddly enough the rep says to mist surface if too hot, oh wait a minute now you have a moisture problem again. It just becomes a finger pointing affair that you never win. But cementious stucco is less suseptable to all the variables of what can go wrong

laclu;

the other problem with a concrete roof  in hot climates is it's thermal mass stays warm.

Posted By laclu on 16 Feb 2010 09:11 PM

The other subject is roofing coatings, not flat roofing, low slope or a regular 4/12 pitch.  Is there anything out there that I can just put in the concrete or seal the concrete with to provide waterproofing, colour? , or do I have to put a tin or membrane over it ?
Thanks Randy

There are admixes like Hycrete to make hydrophobic concrete, but shrinkage cracks can defeat these products.  Good concrete >4500psi or so is virtually waterproof by itself,  but again, cracking can be a problem.  I have more faith in traditional solutions.

There is nothing wrong with concrete construction in a seismic zone as long as it is properly designed and constructed. 

Bruce

Post tensioned cables + glass fibers supposedly do a good job of preventing cracks in concrete.

Posted By jonr on 17 Feb 2010 05:35 PM

Post tensioned cables + glass fibers supposedly do a good job of preventing cracks in concrete.

post tensioning won't prevent cracks, but if they occur, the end bolts can be cranked up to close the cracks up

Posted By jonr on 17 Feb 2010 05:35 PM

Post tensioned cables + glass fibers supposedly do a good job of preventing cracks in concrete.

I thought there are only two kinds of concrete; concrete that has cracked, and concrete that hasn't cured yet!

Randy:

I would suggest you contact manufacturers of the acrylic coatings to get the word "straight from the horse's mouth. We have built structures with these coatings in the Caribbean, Central America, Middle East (yes, Persian Gulf area has extremely high heat and high humidity) and the Philippines without the "catastrophic failure" that some of these posts would lead you to believe are imminent.

Products such as xypex will actually produce crystalline structures to seal cracks, that is one of the salient features of these products which may seem a bit contrary to previous comments. You can also look up products from Euclid and Sonneborne that will provide UV resistant coatings that are also severe service coatings that provide waterproofing and abrasion resistance for applications such as parking garages, etc. that would work as a finish coating for your roof application. Degussa which is basically a conglomeration of the major EIFS and TAFS companies in the US is a place to research the acrylic coatings for use in hot, humid climates. Incidentally, they are based in Florida (considered hot humid corrosive climate)

Post tensioning a slab or roof is typically a "one time shot"...... I would be interested in someone producing a "typical and common salient feature" example where the live end of the cables are chiselled out and tensioned to a greater degree after the structure has been in service for any length of time. Typical post tensioning is done within a few weeks of placing the concrete. In the case of a post tension slab above grade, a partial tensioning may be done when concrete strengths reach a minimum psi (to limit shrinkage cracking among other things) and full tensioning done upon a prescribed determination of the concrete strength. Once the cables are tensioned, the live end is typically cut off below the slab edge surface and grouted to protect the live end from corrosion and damage. Should the slab develop any sort of cracking, the solution is not so easy as previously noted to "tighten the bolts". Should there be cracking and the thought of "tightening the cable" more is to be considered, the live end would need to be opened up, the crack would need to be completely cleaned of any dirt or spall and then the determination if the cable can withstand further tensioning without harm to the slab. Opting to use a post tension slab vs. conventionally reinforced slabs is not typically chosen with the thought that it is "serviceable" should something move. Either way, the design of the slab is hopefully enough to do the job that it was intended to do without the thought that "well, we can always tighten the bolts"....

Lite Deck ICF roof systems are commonly specified with a combination of reinforcing steel and post tensioning.....in this case, the lite deck system provides you with an insulation factor as well as attachment points. If you choose to go with a conventional structural slab, these are easy enough to do with a dropped ceiling which allows space for HVAC and other utilities as well as insulation on the underside of the concrete. These methods are common and not reinventions of the wheel. I would contact Mike King of ICF Direct in Amarillo, Texas for more information on post tension roof and floor decks with ICF as he is probably the most experienced engineer in the country with these systems.

Again, I would suggest you discuss your project with manufacturers of the products you are considering as well with engineers that are fluent with the applications of these products and methods. The materials and methods discussed here all work, you will need to have competent people involved with the decision making process, design and installation.

atitagain;

you are correct, it was past my bedtime when I made the post, the cables can be re-tensioned if needed. I had the cable ends in my mind with the self gripping sleeves, not sure what those are called? I mistakenly called them bolts

There are some bolt type systems, but the idea is to prevent the cracks, not tighten them up after they occur. For example, a tennis court that has no cracks or control joints. Post tensioning also saves on steel and concrete.

Glass fibers are supposed to stop the shrinkage cracks that might appear before the tensioning.

http://www.dsiamerica.com/products/post-tensioning/bar-post-tensioning-system/system-description.html

I would be interested in hearing about any residential or commercial concrete roofs over occupied office or living space that rely on admixes such as Hycrete or treatments such as Xypex as the primary line of defense.

Same request for residential or commercial concrete roofs over occupied office or living space relying on bridge and deck coatings as the primary line of defense.

In these situations it would be necessary to place the insualtion under the roof slab.

Bruce

Bruce:

There are two buildings in Grand Cayman (significant rainfall and high heat and humidity) that used Hycrete type product for the roof deck this past fall.  The product was used as the primary line of defense on two three story condominium units with an area of roughly 5000 sf.  The application was chosen for the roof deck terraces with the idea that the purchasers of the roof decks will be able to apply any tile or other finish of their choice at a later date without incompatibility issues.  No leaks that I know of.
In North Texas, there are several AMDeck (Amvic's ICF floor/roof system) with Sonneborne garage floor deck coatings on them.  The ages of these range from 5 or 6 years to less than a year.  No leaks.  There are many more, all you need to do is research the products and perhaps visit the websites looking for project profiles.   Both Sonneborne and Euclid have products made specifically for this application (there are other products out there as well, but we are applicators of these two).  This is not an uncommmon application, these products are made for these applications.  Many commercial parking garages have serviceable space below, additionally, in parking garage applications, if you see water dripping from the surface above, then you ought to park somewhere else as that garage is probably not being maintained properly.  BASF has a tremendous amount of information on these technologies as well.  These guys have a great index of products and applications for just about any issue that can come up for waterproofing and repair. 
http://www.cadeco.com/cadeco.php?se...searchParm  You can spend a lot of time learning by reading the information published by the manufacturers.

Waterproofing concrete should considered in two elements - (1) waterproof concrete, (2) waterproof construction.  Waterproofing admixtures, such as Hycrete, deliver waterproof concrete - keeping water out of the concrete and from going through the concret.

Waterproof concrete, however, is a subset of waterproof construction.  Two adjoining slabs have a joint that must be sealed, as well.  Penetrations must be considered.  And, even with the best construction practices, concrete will always develop some shrinkage cracking.  A waterproofing solution must covers these elements to deliver waterproof construction.

Solutions companies such as Hycrete do the bulk of their work through as systems approach - Hycrete System W, for example - that cover all these elements.  The systems approach incorporates 3 major elements, then - waterproof concrete from the admixture, waterproof construction through the service element (ensuring sealing of joints, maximizing concrete quality, and repairing the inevitable cracks), and a comprehensive performance warranty.

The traditional approaches require membranes.  Membranes are a Bandaid employed to keep water AWAY from the concrete, where the real objective is to keep water away from the OTHER SIDE of the concrete.

Hycrete System W outperforms membranes on durability, risk (minimizing # of responsible parties, failure points, complexity, labor contect, etc.), cost (generally >30% lower cost than membranes), schedule (shaving days or weeks off the construction critical path), and sustainability (eliminating tons of nonrenewable membrane materials from a site, plus the waste).

www.hycrete.com

Respectfully,
Aaron Ayer
Vice President of Marketing
Hycrete

Post Tension ends