SectionHiker.com Backpacking Gear Reviews and FAQs 
If you spray your tent with Permethrin to protect yourself from Lyme-disease-carrying ticks and blood-sucking mosquitos, you should spray the inner tent or insect netting and not the rain fly, which is waterproof and will prevent the Permethrin from soaking in. Permethrin is also quickly broken down by ultra-violet light, so it will break down quickly with sun exposure.
If you decide to treat the inner non-waterproof part of your tent, by spraying or soaking, you want to avoid using Permethrin or Permethrin Concentrate containing petroleum distillates and use water-based Permethrin instead. The petroleum distillates may degrade or ruin any synthetic waterproof coatings on your tent. If in doubt, call the tent manufacturer and ask for their advice. You should also avoid using Permethrin with petroleum distillates on clothing since it can cause skin reactions and can leave an unpleasant odor that lasts a long time. Unfortunately, repeated washing to get rid of the odor will also get rid of the Permethrin.
The only water-based Permethrin or Permethrin Concentrates I’m aware of is Sawyer Permethrin or Martin’s Permethrin 10% Concentrate, although some different formulations of Martin’s do include petroleum distillates, so you should avoid those. Generally speaking, the Permethrin sold in feed stores has petroleum distillates and is not intended for use on human clothing or tents, but for cattle or horses who are more tolerant of it. When in doubt, read the label or search online for the safety data sheet, which lists the ingredients.
Even before you spray your tent, you should spray or soak your clothes with Permethrin (which will last for 6 wash/dry cycles) or send them to Insect Shield for treatment (which will last for 70 wash/dry cycles). Ticks latch onto your shoes and clothes when you walk through vegetation or forest duff and this is the most likely scenario for encountering one.
Would it be effective spraying just the netting, with water based solution, to keep the buzzing insects away from the tent? Or would that have minimal effect?
It’s not a repellent. It kills them. But yes, you could. Just be advised that it will lose its effectiveness pretty quickly from stuffing. That said, they don’t gather on top of the inner tent, but on the underside of the rain fly and since you’re already protected by the netting, you’re not accomplishing much by spraying the inner.
FWIW, permethrin is referenced as a repellent in all literature from manufacturers, the EPA, and the CDC when used to treat fabrics and I have anecdotal success using it as such. I treat my hammocks/bugnets, and tarps with it (incidentally, I lay out my tarp and treat everything on top,) and there is a noticeable difference in swarming between treated and untreated. I had the same results with my Softopper. Upon treating the interior, the bugs stopped coming in. YMMV.
Same here
This is very useful information I was previously unaware of. That you for providing additional information on permethrin.
The only time I ever wished I had permethrin on my tent was one trip at Assateague. The ticks were everywhere. Every time I went to my tent I could see multiple ticks on the fly and on the guylines. If I go back there in the spring again, I’d probably treat my tent beforehand just for that trip.
However, I think things change considerably for a hammock. The hammock fabric is not waterproof so it can absorb the permethrin. More importantly, you’re pressed up against it so it’s possible for a mosquito to bite through the bottom fabric of a single layer hammock. And because I sleep diagonally, some part of my head and feet are usually touching the netting. Also, it’s harder to kill a bug inside a hammock than a tent, if one manages to get inside while you have the zipper open.
Any thoughts on permethrin treating clothes that have been treated with DWR already? I recently put permethrin (spray) on a pair of hiking pants that come from the factory with DWR. The spray was, mostly, beading up and I’m guessing it wasn’t overly effective. I’m inclined to try the soak method moving forward.
Soaking or Insect Shield is the way to go for clothes, although you can get the same effect with spray if you saturate the pants.
Prior to a trip to tick infested Cumberland Island, GA, I contacted Dan Durston about treating my Xmid tent. He said no problem. I set up the tent, sprayed outer fly and inner net. Treated my clothes per Philip’s soak method. I has zero tick issues. Everyone of our group treated their clothes, only a few their tent. Just as Tom witnessed, the untreated tents had a few ticks, primarily on the fly (dark inner netting made ticks hard to see). Note we just packed in a few miles, setup camp under shady live oaks for a few days and packed out. Philip may be correct about treatment not lasting on a daily backpacking trip. Good point on the barn spray perm having petrol distillates.
Why don’t you just keep the doors closed? It has never occurred to me to insect repel a thing that’s already enclosed. If it’s just the outside buzzing of insects, I’d suggest earplugs over chemicals.
I’ve used earplugs for his exact purpose.
For those that love their dogs: spray/soak permethrin on a bandana, let dry, tie around your best friend’s neck.
Ticks are everywhere near my area, even in cold months.
Great idea!!
The active ingredient in K9 Advantix is permethrin. We also use a permethrin based spray for the horses and treat their fly sheets/masks with Sawyer. All Lyme free!
True Josh, K9 Advantix is great stuff, I use the bandana as a secondary measure.
FYI before using Seresto Flea and Tick Collar for Dogs, look into the lawsuit.
It could save your best friend’s life by NOT using one.
I made the mistake of using the petroleum-based Permethrin concentrate. Had to hang my clothes out in the garage for a week to get the smell down to a bearable level. Lesson learned!
Is there a fabric binding agent in the permethrin solution that is made for fabrics? I was just wondering if the Sawyer solution has something that helps it bind to the fabric better.
I don’t know the ingredients but that’s what they say. It is designed for use on clothing.
Sawyer does indeed have an additive for that purpose and I think the only other one is the military aerosol can, which I believe is made by the same manufacturer (Sawyer does not manufacture their own, just labels it). It’s really intended for cotton but has some effect on synthetic fabrics (if memory serves it does better on polyester than it does nylon but it’s pretty minimal). None of the ag products – water or petro carried – include this. I’m not sure if the wash method that InsectShield still uses anything like this but they did at first…their treatment is certainly longer lasting than homebrew applications.
When you say inner tent, do you mean inside the tent (sleeping area) or exterior of tent but under the rain fly?
sleeping area.