Question
During a recent snowstorm, the contractor used calcium to melt the ice that had formed on the TruFlor sub-flooring panels. Are there any issues with this method of melting ice that he should be aware of? What do you recommend?
E. Raymond, NH
Answer
Thank you for the question Edward. I took your question to the APA for expert advice and below is the reply:
“Although most common salts and salt solutions have no significant effect on wood, certain highly acidic or alkaline solutions may reduce its strength. Calcium chloride is slightly acidic which should not affect the strength properties of wood structural panels. Reference APA Research Report 132 (pages 16 & 17).
We discourage use of ice-melting salt(s) due to concerns regarding corrosion of fasteners and connectors exposed to calcium chloride or sodium chloride. We would expect the corrosion rate to increase as a result of such exposure (it is also possible that pitting corrosion will occur). If exposure is limited or short term in nature, engineering judgment may be that significant concern is unwarranted.
A Handbook of Chemical Engineering shows that at concentrations of 50% and at a temperature of 100 F, calcium chloride can corrode steel at a rate of 0.02″ per year. These conditions would be the extreme end of floor exposure.
Calcium chloride is a water absorption agent, which if it gets into the wood fiber could promote water absorption by the OSB sub-floor and prolong the drying process. This could lead to increased corrosion risk.”