The number of times Termidor SC is applied depends on the ratio that is used. At the .03% rate, the product can be used four times a year. The other option is to apply three times a year at the ratios of .03% twice and .06% once. We would recommend checking out the Supplemental Document for this product for any more information.
Termidor SC is the Suspended Concentrate, which is a liquid concentrate. Termidor HE stands for "High Efficiency" because it is the most concentrated product the manufacturer has with this active ingredient, which is more convenience for Pest Control Professionals who may be treating dozens of homes each week. You cannot purchase Termidor HE unless you have a Pest Control Operator's license, and you would need to purchase it from a local distributor in that case. We do not sell this product or other Restricted Use Pesticides.
As long as Termidor SC has time to dry and bind with the soil, the rain will not affect it. It is best to wait until you have a few days of no rain in the forecast so there is at least 24 - 36 hours time after you treat before it rains. After that it will hold quite well to rain and weather.
Yes, Termidor SC is harmful to bees that come in contact with treated surfaces. To avoid bee exposure, we recommend that you follow all label instructions and perform outdoor treatments in the early morning or late evening.
Termidor SC and Timbor are used for two different purposes. Termidor SC is generally a ground treatment, while Timbor is used to treat wood directly. Mixing two insecticides together could potentially cause a resistance with pests. It would basically be like doubling up on a product, and that is unnecessary. Moreover, Termidor is only labeled for spot application to wood where there are active termite infestations; it cannot be broadcast over the wood and would not be absorbed into it the way Timbor will. It is recommended that you follow the label when using any professional products.
We would highly suggest trenching and treating instead of only treating inside the cinder block wall. Termidor is meant to bond to soil and be applied into the ground. It will not last very long just treating into the cinder block walls. Cinder blocks are also very porous, so they will soak up a lot of the termidor and you might get a few months of protection instead of 10 years when applying it into the ground.
You should follow the instructions as outlined in our How To Do A Termite Treatment article to treat the exterior and underside of your crawl space.
It is completely up to what you prefer, some people are more infatuated with the name brand product Termidor SC but they are the same product and work in the same manner so it is completely left to what you prefer to go with.