Can you please tell me what kinds of signs we should look for to determine if our home was used as a meth lab? What kinds of smells? We have three rental properties as well. We rented out the home we live in now for about a year. When we came back, it looked as if tape had been put on all of the heat ducts. It also looked as if the carpeting had been removed, then put back down. How do we test? Who do we call?

Your home may have been used as a meth lab. The tape over the heating ducts is used to prevent fumes produced during manufacture from traveling out of the ‘cook’ area, and contaminating other areas of the house. Likewise, the carpet would be contaminated if not removed. Problem is, the chemicals used to produce meth are far deadlier than the meth itself, and your floor under the carpet is probably laden with chemicals which need to be removed. A call to your local police can perhaps help if they have a dedicated meth team. If not, call the DEA who will be of some help in guiding you to identify if meth was a problem for your home or not.
Determining whether or not a property has been used as a meth lab starts by listening to your gut instincts. Your questions are good ones! Why would someone put tape on heat ducts? Why would they remove carpet and then put it back down again? Anytime, you see something that appears weird, strange, or out-of-the-ordinary, you should ask yourself “why would someone do that”?
Are what you’ve described signs that your renter made meth in your home? Maybe. Maybe not. The only sure way to know if someone made meth is to test the home for meth and meth making chemicals. You may want to take a look at some of the meth lab signs that I have posted on this site. It is certainly not a full list of every sign associated with meth labs, however it may help you learn more about what you should look for, especially since you rent out property.
There are free meth wipe testing services available which can tell you if any surfaces in your home contain meth residue, although choosing the right location to test if it was a meth lab is important. For example, you could test a wall in one room or two rooms and the results may come back as negative. Yet, if you have tested in another room or another location in that room, the test may come back positive for meth residue. Whether a test comes back positive or negative depends on alot of factors. Doing some free meth wipe testing should only be considered to be a pre-test! Definitive testing should always be done by a professional testing company. Your local health department should be able to provide you with a list of certified meth lab contractors in your area.
Thanks for bringing up some great questions. Good luck to you. I hope it all turns out well!