Intregal Concrete Admixture WaterProofing In Elevated Slabs?
Intregal Concrete Admixture WaterProofing In Elevated Slabs?
(OP)
Anyone use concrete admixture "water vapor proofing" in elevated slabs?
The concern presented is in regards to flooring failures in new construction from slab moisture content.
The concern presented is in regards to flooring failures in new construction from slab moisture content.






RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
I believe that it is supposed to greatly retard moisture movement both in and out of the concrete.
A client who has had many moisture problems is interested in integrating it in all floors, both on grade and elevated.
I have concerns if it might not be metal deck friendly, both in itself and due to the retained moisture. And then there is the question of bond to composite decks.
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
Water is necessary for hydration of cement. If a "waterproofing admixture" or vapor reducing admixture is used, it must be something that reacts with the remaining moisture in the concrete after hydration occurs. This is often done with calcium silicates applied to the surface of concrete after sufficient curing....they produce void-filling calcium silicate compounds from the inherent moisture in the concrete...surface "hardeners" if you will.
The other approach is something to encapsulate or isolate the moisture within the concrete as hydration occurs. This is the premise of a "waterproofing" admixture such as Xypex or similar. How much of the moisture can it bind and how much can it leave available for hydration?
Answer this question and you can decide if a "waterproofing" admixture works or is even appropriate.
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
OR if you dont want to risk weird reactions with metal or the surrounding environment just use a hella low water to cement ratio. It's as good as waterproofed. Permeability goes way way down. Sounds like this is a good job for a concrete consultant to recommend the right mix.
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
This is about the moisture content of recently poured slabs creating floor finish bond failures. Apparently there is concern for potential problems long (6 plus months) after placing the concrete. Widely variable test results have elevated the insecurities.
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
Would this have long term effect on the concrete, metal deck or reinforcing materials or bond?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
We have bond tested waterproofing coatings on concrete slabs and achieved bond strengths in excess of 1.0 MPa (145 psi). If you have good surface prep and good environmental conditions during installation and can achieve at least a 0.6 MPa bond strength at installation it unlikely to debond due to vapour pressure in the future. Vented deck may reduce the chance of vapour pressure building up behind the membrane/coating.
In the past, we have specified vented decking, however, see below link from the Steel Deck Institute which tends to discount the effects of venting and hanger tabs.
http://www.sdi.org/papers/PPVENT.pdf
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
Both versions retard your set time greatly even though neither manufacturer wants to talk about that. I even used it in my own personal elevated slab, and the finisher waited from 8am until 2am the next day before he could get on it. The set time is a bit problematic for wall forms as we have learned.
Brad
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
Setting time is not the only thing these manufacturers don't want to talk about. The necessity for extensive crack control reinforcement, as you pointed out, was formerly emphasized, but now is not. I have investigated several leaking decks where dependence had been placed on Xypex, only to have big problems with leaks onto the expensive cars below. The crack control had been neglected.
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
I recently received the new Kryton magazine and was surprised to see they are suggesting using the KIM in an ICF form. We get involved in a lot of ICF's and know how important the form pressure is. I cannot imagine how they can do this for an ICF form. Form blowouts will be a huge problem if they fill an 8' tall form, and it will only get worse after that.
Brad
RE: Intregal Concrete Admixture WaterProofing In Elevated Slabs?
If the dosage is low enough to prevent damage, it will not fill the voids appropriately.
Use other means to "waterproof" concrete.