When we think of insect repellent, the first thing that comes to mind is "OFF" spray on insect repellent for our bodies. However your body isn't the only thing that will be attacked and invaded by insects. What about your home? Currently your home is protected by plastic, asphalt, bricks, vinyl siding, screens and gasket like seals. But what about that survival home you had to build in the woods with an ax?
We have come to enjoy a home virtually devoid of insects, but if you aren't careful that will all come to and end if you are forced to abandon you current home in order to survive after the SHTF. A 100% seal isn't likely in survival structures, but thankfully all is not lost. You can easily make an insect repellent spray for your home to help deter them from entering and also to deter them from eating the home itself.
To make the home insect repellent you collect wood ash from a hardwood fire and place the ash in a non-metal container. Then add water, soak the wood ash for a week. If you have pepper available then add that as well.
After a week, you simply paint the liquid onto the surface of the wood. In moderation it can be used inside as well as outside. Reapplication will be needed as it isn't a long lasting treatment.