insect repelant on non absorbing mat'ls

shortly I'll be ordering some "soft" tyvek for a tent footprint. I intend to treat both tent and F.P. with a Permethrin soaking. now I assume that the ultimate would be if the insect repellent was absorbed. but there's not much absorption with the types of materials used in modern day camping fabrics. and I suspect that near zero for the tyvek. would a soaking of a week, force the insect repellant deep into the fabric? or is the best I can expect is to coating on the surface?

Why do you plan on doing this treatment? IIRC, pyrethrum is not a repellent, it is a toxin both for insects and for humans in sufficient quantity. If your tent has a reasonably good zipper setup then bugs won't get in enough to cause problems and an insecticide treated footprint would not be of any help.

It seems to me as though you may be trying to solve a problem you are not likely to have and would be exposing yourself to low doses of a potentially toxic compound in doing so.

Pyrethrum evolved as a toxic compound to keep the chrysanthemum in which it evolved from being eaten: by insects or by animals. This is one reason that I avoid pyrethrum treated clothing, the other reason being that I have not found it necessary.

Suspect it won't adhere to coated fabrics at all regardless of the time invested, so tent floors and rainflys aren't going to take the treatment. (Also don't want to inadvertently damage the DWR or waterproofing.) Tent canopies of netting and uncoated nylon will take it. Tyvek? I have no idea but don't see a value and conversely, it could kill a lot of beneficial bugs living at the soil surface while the mosquitoes wouldn't come in contact with it.

Once your out of tent's protection is where the problem is. Treating anything involved with the tent is a waste of time, and possibly harmful as already stated. Treated clothing and head nets are a better solution.

The OP said permethrin, not pyrethrum. Of course permethrin (especially when encountered as a liquid), like any pesticide, can be carcinogenic, which is why it's extremely important to take precautions (like rubber gloves and a face mask, and applying it outdoors) when using it. It's also a broad-spectrum pesticide which can kill a number of beneficial insects, so its use should be limited.

I have been known to spray my tent door netting when going into a really buggy area, which hopefully keeps an accumulation of hungry bugs from zooming in before I can get out and close the zipper. As the other responders have mentioned, there's no point in spraying the tent itself. IMHO, the less chemicals used, the better.

A tent footprint is UNDER the tent. It is sandwiched between the tent floor and ground. Your chances of mosquitoes biting through the floor to get you are pretty slim, if at all.

The mosquitoes between the floor of your tent and your groundcover would be pretty slim, too!

my worries run mostly towards ticks ( a insect that, frankly- it's hard to feel all that warm n fuzzy towards). and to an lesser extent, scorpions when in the southern climes. I done some reading about washing tyvek to decrease the material's tendency to be noisy. the article suggest that it does absorb water, when agitated, as in a washing machine.( no mention about doing so with insults and bad jokes) it seems to take some time to dry after washing which suggested that it reluctantly, absorbs.

Ticks will not get into a closed screened tent with floor, unless they hitch a ride in on your clothing. They certainly aren't going to bite through the floor! Scorpions can't get in, either, and insecticide won't do much to them anyway. Spraying the tent and ground sheet is a waste of money and an unnecessary exposure to the chemicals. Maybe spray the netting screen door, but not anything else.

The only time you would want to spray a ground sheet is if you have a floorless tent with no screening. In that case, of course, the crawlies can enter freely. If you have problems with ticks and scorpions (and ants), you definitely want an enclosed tent.

Actually, ticks are not insects; they are arachnids, like spiders. Not that this relationship makes them any more likable!

Permethrin is a synthetic insecticide based on pyrethrum.

"Permethrin ("per-meth-rin"), on the other hand, is a synthetic, man-made insecticide, whose chemical structure is based on natural pyrethrum. The so-called pyrethroid insecticides were developed to match or exceed the effectiveness of natural pyrethrum but be more stable in sunlight".

The above is a quote from a website on permethrin to which I can't seem to post a link 😕.