A general rule-of-thumb for concrete drying is one month for every one inch of concrete thickness when the slab is 3" thick (under good drying conditions). For each additional inch of slab thickness, dry times increase exponentially, i.e. a 4" slab might take 5 months, an 8" slab 12 months. Add to this wet, west coast weather, and dry times are definitely not on the construction schedule’s side.
One thing is for sure - if the concrete is not dry in time for the scheduled installation start date, a decision will have to be made. The choices are these:
1. Delay installation and wait for the concrete to dry to recommended levels.
2. Install a moisture barrier.
3. Switch the flooring system and or products.
All too often, a fourth option is taken…
Proceed with the flooring installation (against manufacturers’ installation guide lines), waive the warranty and risk moisture related problems later on.