Decorative contractors spend time and money they can’t afford repairing sealer problems that hurt their reputation and delay payments. The final application of a sealer is a small item on an estimate sheet, but one with big consequences to cash flow when failure occurs, which is all too common.
Recognizing this, on Dec. 1–2, 2011, the American Society of Concrete Contractors (ASCC) and its Decorative Concrete Council (DCC) organized a conference sponsored by Concrete Construction (CC) magazine to discuss problems contractors have with thin-film sealer applications. Bev Garnant, ASCC executive director, says she’s heard contractors complain about sealer problems for years and decided it was time to do something.
Conference attendees were decorative concrete contractors, formulators of sealer products, distributors of decorative products, and manufacturers of resins used to make sealers. The discussion was limited to solvent and water-based acrylic sealers for exterior and interior use.
Contractors often blame manufacturers for application failures and manufacturers respond with, “Our product is manufactured properly so the problem is how you installed it.” But blaming is a dead end. Collaborative relationships between manufacturers, distributors, and contractors are the only way to solve problems. So the ASCC and CC invited all parties to gather to discuss the problem and come up with solutions.
What manufacturers need to do
Legally, all manufacturers must provide material safety data sheets (MSDS). But better work results when the relationship between contractors and manufacturers is more collaborative. Manufacturers should consider:
Provide instructional manuals and guidelines. Include information such as product UV susceptibility, gloss level, abrasion resistance, tools and tricks, and maintenance requirements.
- Offer troubleshooting help to contractors when they experience failures (contractors often have no idea why failures occur). Provide troubleshooting guides with photos of failures and related descriptions of cause.
- Provide data sheets for each product listing favorable ambient jobsite conditions: temperature, humidity, air flow, and dew point.
- Create a database of jobsite failures for each product. Data accumulation can suggest trends and solutions.
- Increase contractor training.
- Communicate changes to products contractors regularly use so they know what to expect.
How to install sealers
Conference attendees agreed that many contractors don’t follow the best procedures when planning for and installing acrylic sealers. Here are some suggestions:
Experienced crew. Have an experienced and well-trained team install sealers and perform maintenance work. Avoid sending whoever is available to do this work.
Preparation is key. Provide the surface profile that sealer manufacturers specify for their sealer for each decorative treatment. Preparation methods might include power washing, acid washing, light sand or soda blasting, or diamond grinding. Oils or spills due to other trades must be removed as well. Consult with the International Concrete Repair Institute’s website at www.icri.org for surface preparation guidelines.
Consult manufacturer prejob checklists. If the manufacturer of your product doesn’t supply written information, call your sales rep and ask for the jobsite ambient condition requirements. You need to know temperature, relative humidity, slab moisture, slab pH (sealers have acceptable pH ranges), and wind speed limits. Record the information on the job sheet for future reference.
Additional equipment. To observe jobsite conditions, equip your crew with the following:
A handheld weather meter to measure ambient jobsite conditions such as temperature, wind speed, RH, dew point. The Kestrel Co. in Boothwyn, Pa., (www.nkhome.com), makes the Construction Weather Tracker Kestrel 4300, which also tells you if surface crusting conditions are present when placing concrete. The conditions that cause surface crusting might also be the same ones that cause sealer problems.
- An infrared thermometer to read slab temperatures.
- pH paper/test strips or pH pencil to measure slab pH.
- Calcium chloride test kit (for moisture vapor emission rate) or moisture meter.
Thin is in. Epoxy and urethane coatings can have thicknesses up to 30 mils, but acrylic sealers require thin-film applications (2 to 5 mils). Installing them thicker—to achieve a higher gloss appearance—limits the sealer’s ability to pass moisture, increasing the risk of failure.
Know what’s already there. Serious compatibility issues between sealer products can lead to expensive repairs. These include penetrating sealers and spills left by other trades. The manufacturer of your product can help you with information about which families of products to avoid. Lithium densifiers, on the other hand, may enhance the bond and performance of all acrylic sealers.
Educating the consumer
Consumer expectations and absence of knowledge about the products installed on their work are reasons failures occur. Sometimes, owners want an appearance that won’t work on their project; the decorative contractor needs to present realistic expectations. Contractors should provide owners with maintenance manuals that include the name of the sealer, cleaners to use, stain susceptibility, and how the work should be maintained over time.
New VOC regulations established by the Environmental Protection Agency (EPA) mandate the use of approved solvents, cosolvents, and surfactants. Percentage levels of solids also are being increased. As a result, the window of opportunity for ambient jobsite conditions is narrower for successful installations. You need to educate yourself and your sealer crew to be able to install quality products, even when they require greater care.
This conference marks the beginning of an effort to produce guideline statements, checklists, training, care and maintenance documents, and troubleshooting help for ASCC–DCC members to help them solve problems and save money—another reason to become a member.