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What Lurks Under Your Floor?

What Lurks Under Your Floor?. ICRI 2010 SPRING CONVENTION Thursday April 15 th 2010. Presented By: Brian Cordak. MOISTURE VAPOR EMISSION. Understanding The Challenge: Moisture Activity In Concrete. Moisture Activity In Concrete CAN BE ENCOUNTERED EITHER IN:. In Liquid Form

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What Lurks Under Your Floor?

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  1. What Lurks Under Your Floor? ICRI 2010 SPRING CONVENTION Thursday April 15th 2010 Presented By: Brian Cordak

  2. MOISTURE VAPOR EMISSION

  3. Understanding The Challenge: Moisture Activity In Concrete

  4. Moisture Activity In ConcreteCAN BE ENCOUNTERED EITHER IN: • In Liquid Form • Capillary Action • Hydrostatic Pressure • Measured in psi. OR

  5. Moisture Vapor TransmissionA COMMON OCCURANCE IN THE FLOORING INDUSTRY • In Gas Form • Diffusion Action • Vapor Static Pressure • Measured inlb/1000 ft2/24 hr. • (MVER)

  6. Failure of a Water Based VCT Adhesive Due to Moisture Vapor Emission Photo courtesy of Construction Technology Laboratories, Inc."

  7. Failure of a Polyurethane Adhesive Due toMoisture Vapor Emission Example running track

  8. Failure of an Epoxy Mortar Overlay Due To Moisture Vapor Emission

  9. Failure of Trowel Down Epoxy Coating Due toMoisture Vapor Emission

  10. Failure of Thin Film Epoxy Coating Due toMoisture Vapor Emission

  11. The Common Denominators? All Result In Lost $$$ Probably Could Have Been Avoided!! Increased Liability

  12. WHEREVAPOR EMISSION PROBLEMS APPEAR • SLABS ON GRADE • SLABS ABOVE GRADE • SLABS BELOW GRADE

  13. GENERALLY SPEAKINGVAPOR EMMISSION PROBLEMSCAN BE CATAGORIZED IN ONE OF TWO WAYS 1. Concrete Drying Issues “Closed Slab or Above Grade Situations” 2. Chronic Diffusion Issues “Open Slab Situations”

  14. CLOSED SLAB SYSTEM A Closed Slab System is where an PERMANENT VAPOR BARRIER or non-perforated metal decking is in place directly beneath the concrete. In a Closed Slab System the only source of moisture is free-water originating from within the concrete itself.

  15. OPEN SLAB SYSTEM An Open Slab System is the most challenging condition for a topical moisture & pH suppression system as moisture within the concrete will typically rise above the originally tested levels over time.

  16. SOME COMMON CAUSES OFVAPOR EMMISSION PROBLEMS • OLDER BUILDING Without Any Under Slab Vapor Barrier • OLDER BUILDING With a Damaged or Deteriorated Under Slab Vapor Barrier

  17. COMMONLY OVERLOOKED SITUATIONS LEADING TOPOTENTIAL VAPOR MOISTURE TRANSMISSION PROBLEMS • Renovation Or Reconfiguration OfExisting Space • NEW CONSTRUCTION With A Compromised (Direct Contact) V.B. or Fill Saturated Before Slab Pour (Indirect Contact)

  18. GENERALLY IGNORED SITUATIONS LEADING TOPOTENTIAL VAPOR MOISTURE TRANSMISSION PROBLEMS Renovation Or Reconfiguration OfExisting Space • NEW CONSTRUCTION With Compromised (Direct Contact) V.B. • Fill Saturated Before Slab Pour (Indirect Contact) V.B. • FAST TRACK/NEW PROJECT: No Time to Wait for Concrete to Fully Dry

  19. Reasons Achieving Proper MVER in New Construction Can Be Difficult 2. WATER Of Convenience In The Fresh Concrete Mix 1. Concrete Or Fill Moisture Events

  20. Amount Of WATER In Fresh Concrete • Example: A simple 6-sack concrete mix consists of • 564 lb cement/yd3 (Type I, II, …..) • ~3,200 lb aggregates/yd3 • Water for mixing, placing & hydration of cement • Additives (superplasticizer, air entrainment, etc.) • W/C (water/cement ratio): 0.5 assumed • Typical Amount of WATER: 0.5 x 564 lb = 282 lb • = 34 gal/yd3

  21. Total WATER in concrete • mix = 34 gal/yd3 • b.REQUIRED: • WATER for hydration of cement ~35% = 12 gal/yd3 • c.RESULT: • ~65% surplus WATER needs • to evaporate = 22 gal/yd3

  22. How Long Until Concrete Is Dry?Blow 75% RH(Actually Under 3 to 5 lbs of MVER) Rule Of Thumb For Concrete Drying Time: ONE MONTH PER 1” OF SLAB THICKNESS (Typically Will More Than Double In Winter) Lightweight Concrete Mix Designs Dry At A Rate 2 Times (or more) Than Normal Concrete ALWAYS TEST TO BE SURE!!!

  23. How Is Moisture Vapor Emission Measured? ASTM F 1869 3 Test Kits For The First 1000 S/F of Floor & 1 Additional Test Kit For Each Additional 1000 S/F Example: 7000 S/F = 9 Total Test Kits Calcium Chloride Test Kit

  24. Insufficient Number of Calcium Chloride Tests X

  25. How Is Moisture Vapor Emission Measured? Another New Test Method Is Currently Being Used: ASTM F 2170 Test Method For Determining Relative Humidity In Concrete Floor Slabs Using In-Situ Probes

  26. HOWDOES VAPOR EMISSION CAUSE FLOORING SYSTEMS TO FAIL?

  27. Moisture MovementThrough Interior Slabs On Grade VAPOR EMISSION Varies Throughout The Slab Itself May Also Fluctuate During Different Times Of Year

  28. Moisture Vapor Emission TRANSPORTS MINERALS & CONDENSATES AT SURFACE

  29. pH Scale is Logarithmic • pH 7 is Neutral • pH 7 and Lower is Acid • pH 7 and Higher is Alkaline • pH 7 ---to--- pH 14 is 10 MILLION • Adhesive Warranty pH 8.2 to 9

  30. How Should One Proceed When MVER Is Not Within The Required 3 or 5 lbs/24 hr*1000 ft2 or Below 75% RH • Risk Installing the Floor System? • Pretend It Is Not A Problem? • Run Away & Hide? • NO!

  31. Vapor Suppressant Install A Quality “Negative Side” or Surface Applied VAPOR SUPPRESSANT

  32. Various Vapor Suppression SystemsCurrently there are 6 major system categories or material approaches being marketed tomitigate a high moisture or pH condition in concrete sub-floors. Treatments rangefrom single coat applications to multi-stage systems that combine two or morecategories of materials.1. Reactive PenetrantsReactive penetrants are fluid applied treatments designed to penetrate the concretesurface and react chemically with the concrete. The goal of such treatments is toreduce the moisture vapor emission rate (MVER) and to bind up soluble alkali suchthat high pH levels are not experienced at the concrete/adhesive interface.The most common reactive formulations used for moisture & pH suppression arebased on sodium silicate, potassium silicate or lithium silicate.Before giving consideration to a silicate-based, reactive penetrant one must havethorough knowledge of the concrete composition and degree of surface carbonation.Concrete mixtures that contain pozzolanic materials such as Fly Ash or Slag canreduce available reactive material within the concrete and thus lead to incompletereaction of the silicate-based treatment. Concrete that is more than superficiallycarbonated may produce a similar result. Not only will un-reacted silicates notachieve the desired reduction in the moisture vapor emission rate (MVER) but theycan inhibit the bond of subsequent flooring or coating applications.Reactive penetrants, as a stand alone treatment, are considered a very high riskapproach to topical moisture and pH suppression.2. Cementitious DensificationModified cementitious overlays are intended to isolate the concrete surface fromadhesives or coatings applied above. Such systems are intended to lower moisturetransfer and restrict soluble alkalis within the concrete sub-floor from reaching theadhesive/overlay interface but can be inconsistent in efficacy.

  33. Various Vapor Suppression Systems3. SealersFluid applied sealers are available to help reduce moisture transfer and isolate theconcrete from the adhesive applied above. Most sealers have warranty limits between 8 & 12 lbs or less and low ph stability. Therefore sealers should be limited for closed slab systems where the demands and required performance is limited.4. Specialty CoatingsHybrid epoxy-based or epoxy-modified coatings, specifically designed for highmoisture/pH conditions, reduce the Moisture Vapor Emission Rate (MVER) and actas an isolation barrier to keep solutions of highly alkaline salts within the concretefrom reaching the subsequently applied adhesive or coating.One, two and three coat systems are available. Some systems may require multiple coats to achieve sufficient mil thickness on very aggressively shot blasted concrete.Additional leveling or cementitious substrate material may be required over thecoating. When that becomes necessary the materials and processes to follow should be approved by the manufacturer of the suppressant system.5. Dispersement MembranesDispersement membranes were historically one of the first approaches to topicalmoisture suppression that experienced a reasonable measure of success. Suchsystems utilize a special fabric adhered to the surface of the concrete whichprovides a lateral avenue for water vapor to diffuse. These membranes are only for floating systems.6. Combination SystemsSeveral companies utilize a combination or “Cocktail” approach where two or moreof the systems discussed above are combined, but this approach is usually cost prohibitive

  34. DEFICIENCIES OF INFERIORSURFACE APPLIEDVAPOR SUPPRESSANTS • MANY VAPOR SUPPRESSANTS CAN ONLY PROTECT UP TO 8, 10 or 12 LBS MVER (NOT FOR OPEN SYSTEMS) • FEW VAPOR SUPPRESSANTS CAN WITHSTAND 25 LBS OF MVER • STILL LESS ARE 1-COAT SYSTEMS! 2-COAT & 3-COATSYSTEMS AREAVAILABLE….BUT WHY?!? • BEWARE!!! MANY DO NOT PERFORM IN HIGH ph ENVIRONMENTS OF 13 TO 14 • HAVE MOISTURE SENSITIVE CHARACTERISTICS

  35. Desired Capabilities Of Quality Surface Applied Vapor Suppressants: • Must Have Ability To Be Applied To “Fresh” or Old Concrete • Must Withstand Constant pH 13 – 14 (Normal pH of fresh concrete is 12 – 13) (Aged concrete has a pH 8 – 10) • Must Provide Proper pH On Surface For Flooring Applications (Neutral = 7) • Must Tolerate High or Unknown MVER • Moisture Insensitive Formulation(Damp Surfaces OK!)

  36. STEPS TO SUCCESSFULVAPOR SUPPRESSANTINSTALLATIONS

  37. ALWAYSEvaluate & Diagnose Existing Floor

  38. TEST FOR SUCCESS • Extract Core Samples From Both.. Affected & Unaffected Areas • Analyze Cores In Lab Under Scanning Electron Microscope (SEM) • Analyze Cores Using Ion Chromatography • Analyze Cores Using Infra Red Spectro Photometer

  39. Example of Test Cores

  40. Example of Ion Chromatography Test Results

  41. Example of Infrared Spectroscopy Test Results • Core #1 (MI#28014-01C); 0-3 mm BTC The amount of organic extractable residue comprises approximately 11,100 ppm (1.110%) of the concrete mass. The IR spectrum of the residue indicates the presence of alkyd and polyester resin material. • Core #1 (MI#28014-01A); 3-5 mm BTC The amount of organic extractable residue comprises approximately 8940 ppm (0.894%) of the concrete mass. The IR spectrum of the residue indicates the presence of alkyd and polyester resin material. • Core #2 (MI#28014-02A); 0-3 mm BTC The amount of organic extractable residue comprises approximately 16800 ppm (1.680%) of the concrete mass. The IR spectrum of the residue indicates the presence of alkyd and polyester resin material. • Core #2 (MI#28014-02C); 3-5 mm BTC The amount of organic extractable residue comprises approximately 9,390 ppm (0.939%) of the concrete mass. The IR spectrum of the residue indicates the presence of alkyd and polyester resin material • .* Note: ''BTC' = Below the Top surface of the Core

  42. Surface Preparation! ACID ETCHING? ABSOLUTELY NOT!!!

  43. Proper Surface Preparation SteelShotblasting

  44. Proper Surface Preparation Grinding

  45. Proper Surface Preparation Scarifying

  46. ConcreteSurface Profiles CSP- 2 CSP- 3 CSP- 4 X CSP- 5 CSP- 6 CSP- 7 CSP- 8

  47. Degrease If Needed! Remove All Contaminants

  48. Proper Surface Preparation Remove Excess Water & Puddles

  49. Mix Thoroughly & Spread Suppressant at Prescribed Rate

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