1 / 67

Presented By: Mike Mudrick

2012 ICRI Carolinas Chapter Fall Convention. Coating Failures, Causes, Preventative Measures & Repairs. Executive Development Center 1241 Military Cutoff Rd #A, Wilmington, NC. RESIDENCE INN FRIDAY OCTOBER 12 th 2012. Presented By: Mike Mudrick.

sarah
Télécharger la présentation

Presented By: Mike Mudrick

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2012 ICRI Carolinas Chapter Fall Convention Coating Failures, Causes, Preventative Measures & Repairs Executive Development Center 1241 Military Cutoff Rd #A, Wilmington, NC RESIDENCE INN FRIDAY OCTOBER 12th 2012 Presented By: Mike Mudrick

  2. Vapor Moisture Transmission In the Construction Industry

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

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

  5. DIFFERENCES BETWEENGAS FORM & LIQUID FORM Vapor Emission (GAS)Pressures: • Humid gas passing through the capillaries of the concrete with minimal pressure, very little water, and will dry out when surface is not covered. Hydrostatic(WATER) Pressures: • Generally moderate to high pressure, measured in PSI, saturates the concrete, moves laterally, and remains constantly wet.

  6. FLOORING FAILURES DUE TOMOISTURE VAPOR EMISSION

  7. Acrylic Based VCT Tile Adhesive Failure Photo courtesy of Construction Technology Laboratories, Inc."

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

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

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

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

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

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

  17. 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

  18. 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)

  19. 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

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

  21. 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

  22. 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

  23. WHAT IS DRY CONCRETE ANYWAY?!?! Isn’t Concrete Is DRY In 28 Days?NO!! Concrete Is Only CURED In 28 Days!Not Acceptable RH%Not Under 3 to 5 lbs of MVER Rule Of Thumb For Concrete Drying Time: AT LEAST ONE MONTH PER 1” OF THICKNESS (Will More Than Double In Winter) Lightweight Concrete Mix Designs Dry At Rate 2 Times Longer Than Normal Concrete ALWAYS TEST TO BE SURE!!!

  24. Concrete Drying Times

  25. 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

  26. CALCIUM CHLORIDE TEST • ASTM F-1869 • Measured in Pounds, of the Amount of Water Emitted from 1000 sq.ft. of Concrete Over 24 hours. • (8 lbs = 1 gallon) NOT PSI….. • Proper Testing Requires 1 test per 1000 sq.ft. With a Minimum of Three Tests. • Space MUST Be “Climate Controlled” 48 Hours Prior to Kit Placement and Conditions Be Stable Throughout the Test. • The Surface Should be Ground, Clean and Remain “Open” 24 Hours Prior to Placement. Tests Require 62 to 70 hours.

  27. Improperly Performed Calcium Chloride Tests X

  28. 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 • Pros • Precise, accurate • Can be quickly re-measured • Not AS influenced by ambient conditions • Cost effective • Easy to track drying • Proven accuracy

  29. Relative Humidity Probes • ASTM 2170 • R. H. Probe Hole Depth 40% Of Slab Thickness • 5” Thick Slab x .40” = 2 Inches Deep • Drill & Clean Hole, Insert R. H. Probe • Allow R.H. Probe to Acclimate as Required by Manufacturer Before Obtaining Readings

  30. WHERECAN VAPOR EMISSION PROBLEMS APPEAR? • SLABS ON GRADE

  31. SLABS ON GRADE Outdoors Indoors

  32. WHERECAN VAPOR EMISSION PROBLEMS APPEAR? • SLABS ON GRADE • SLABS ABOVE GRADE

  33. SLABS ABOVE GRADE Structural Concrete Components Concrete on Non-Vented Metal Deck

  34. Rehabilitation Or Remedial Projects

  35. HOWDOES VAPOR EMISSION CAUSE FLOORING SYSTEMS TO FAIL?

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

  37. Moisture Vapor Emission TRANSPORTS MINERALS & CONDENSATES AT SURFACE

  38. SOLUBLE METAL IONS • Calcium Hydroxide: “Free Lime” • Potassium Hydroxide: “Caustic” • Sodium Hydroxide: “Unstable” • Result: Dissolved metal ions raise the pH levels in the “solution” allowing a chemical attack on the organic compounds.

  39. WHY NOW…. I Never Had Problems Before?!?! VolatileOrganicContent REQUIREMENTS CHANGED IN THE LATE1990’s The Real Issue Is High Ph NEW GENERATION OF PRODUCTS DO NOT PERFORM WELL IN HIGH pH ENVIRONMENTS

  40. pH Scale is Logarithmic • pH 7 is Neutral • pH 7 and Lower is Acid • pH 7 and Higher is Alkaline • A pH of 13 compared to a pH 7: 1 MILLION Times More Alkaline!! • Adhesive Warranty Limits: pH 8.2 to 9

  41. 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!

  42. APPLYA QUALITY SURFACE APPLIED VAPOR SUPPRESANT WHEN: MVER Is Greater Than 3 or 5 lbs OR Relative Humidity % Is Too High IF HIGH MVER or RH% IS IGNORED YOU RISK SUFFERING COSTLY FAILURES & REPAIRS

  43. Various Vapor Suppression SystemsCurrently there are 6 major system categories or material methods 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.

  44. 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

  45. 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

  46. 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!)

  47. HOW MOISTURE RETARDING EPOXY COATINGS WORK Vapor Suppressant Vapor Suppressant V. B.

  48. Epoxy Vapor Suppressant Penetration Vapor Suppressant Thickness Vapor Suppressant Penetration Microscopy Showing Penetration Of The Vapor Suppressant

  49. STEPS TO SUCCESSFULVAPOR SUPPRESSANTINSTALLATIONS

  50. ALWAYSEvaluate & Diagnose Existing Floor

More Related