The International Concrete Repair Institute (ICRI) revised and updated technical guidelines No. 310.2R-2013, “Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair” in 2013 and yet many architects and
resinous flooring experts have still not modernized their practices.
These guidelines outline what equipment is needed to achieve each concrete surface profile (CSP) grade and the correct CSP for the protective flooring system chosen.
This is very helpful for an installer as flooring product manufacturers specify the type and quality of the surface preparation that is required to ensure the success of their product.
While it would be difficult, if not impossible, to explain all of the various techniques used to perform a complete survey of existing conditions this blog post will explain the basic criteria that are assessed.
So how do these guidelines aid the selection of the proper concrete surface preparation method that adheres to the manufacturer’s specifications? One of the best tools provided is a checklist for assisting in specifying surface preparation, including:
- Evaluation of:
Substrate condition
Material to be installed
Job-site conditions
- Review of surface preparation method(s)
- Selection of surface preparation method(s)
4.Surface preparation requirements
Profile (CSP)
QC testing criteria.
Before you even start evaluating the condition of the substrate you will want to consult with the manufacturer’s specifications to determine what special properties or characteristics the flooring system material may have.
The next step is determining the condition of the substrate. You will want to evaluate the substrate for qualities such as strength, deterioration, existing coatings, and many other factors to help determine the type and amount of surface preparation needed.
The ICRI provides a checklist for a thorough substrate evaluation to help visualize the general to specific qualities to assess.
Substrate Conditions Evaluation Checklist
- Surface Conditions
Efflorescence, Encrustations, Solid
Surface Imperfections
Previous Patches
Bond Breaking Contaminants
- Soundness
Delaminated concrete depth
Cause of deterioration
Pull-off tests
Chloride content and penetration depth
Carbonation depth and pH
- Hazardous Materials
PCB
Frangible Asbestos
Chemicals
Lead
Heavy Metals
- Finish
Formed Wood Float
Metal Trowel
Power Trowel
Broom Finish
Sacking
Storing
Block
Shotcrete
- Moisture
Concrete Maturity (Fresh/Green Concrete)
Hydrostatic Pressure
Substrate Moisture
Vapor Barrier Present
No Vapor Barrier
Drainage
- Joints and Cracking
Cold Joints
Construction Joints
Expansion
Dynamic
Static
Crazing
Leaking
- General Observation
Permeability (inhibit penetration)
Section thickness
Required depth of removal
There is no way to select the surface preparation method without first knowing the properties and application requirements of the flooring system to be installed. The repair material and/or flooring system will strongly influence the surface profile and surface preparation needed.
Speaking generally, the protective system and repair material should be analyzed by its substrate strength, profile, application thickness, moisture tolerance, and alkali tolerance. Again there is a checklist provided for a thorough substrate evaluation.
Material Requirements Evaluation Checklist
- Substrate Strength
Tensile Bond Strength
- Profile
Sealers 0-3 mils (0-0.075 mm) CSP 1-2
Thin Film Coatings 4-10 mils (0.01-0.25 mm) CSP 1-3
High Build Coatings 10-40 mils (0.025-1.0 mm) CSP 3-5
Self-Leveling 50 mils-1/8 inch (1.2-3.0 mm) CSP 4-6
Polymer Overlays 1/8-1/4 inch (3-6 mm) CSP 5-9
Concrete overlays, toppings and repairs >1/4 inch (>6 mm) CSP 5-10
- Other
Application Thickness
Moisture Tolerance
Cleanliness (dust)
The most difficult and lengthy factor to evaluate is the job-site conditions as there are so many variables to assess such as noise, vibration, dust, and water.
There are also many concerns the facility owner may raise such as uninterrupted use of the facility, concerns about the operating environment, or property damage potential may limit the choice of surface preparation method.
The areas of concern can be broken down into three main categories: Accessibility, environmental considerations, and mechanical data – utility supply (type, availability, access location, and cost). All concerns can be seen on the checklist below.
Jobsite Conditions Evaluation Checklist
-Accessibility
Physical Conditions
Surface Orientation
Obstacles
Exposure
- Environmental Considerations
Recycling/Disposal
Airborne (i.e. abrasive blasting)
Liquid (i.e. hydrodemolition water)
Solid (i.e. shot blasting)
Debris (i.e. concrete)
Hazardous Waste (i.e. existing coatings)
Containment
Temperature Conditions
- Mechanical Data – Utility Supply (type, availability, access location, and cost)
Electricity
Compressed Air
Ventilation
Water
Sanitary Facilities
Fuel
Performing a methodical, thoughtful system of evaluation, review, selection, and specification, the proper surface preparation method(s) can accurately and efficiently selected and verified.
While it is not possible to completely outline every step and consideration for undertaking a survey of existing conditions of a project, the guidelines, checklists, and charts provided in the “ICRI technical guidelines: Appendix B” is a great starting point and will greatly enhance the odds of a successful project.
Remember that there is no substitute for an experienced, knowledgeable resinous flooring expert. Armed with your evaluation and selected criteria the next step is to identify the method, or combination of methods, most likely to produce the desired results for the project.