by removing harborage areas around your foundation also a general perimeter barrier of Tempo will be helpful

To explain: by removing harborage such as large rocks, tall weeds, and any kind of debris where daddy long legs hide or any insect to that matter, you will eliminate a majority of insect problems as you are removing the shelter "they" call home. The best way to provide yourself with insect free environment is to remove their shelter, environment, and their food sources, THEN if necessary apply a labeled insecticide which the target pest is on that list of targeted insects. So insect identification is critical, so you will know what issues to target in your IMP (Integrated Pest Management) program. I cant recall what a daddy long leg spider would feed on but many spiders feed on other insects, web locations will indicate whether flying insects are the source of food by(webs high off ground) or if crawling insects are food source (webs low near the ground) I cant say for sure if a Daddy Long Legged Spider even spins a web as honestly I have never had anyone say they were concerned about them so I have never looked it up. I "think" they live and hide under rocks and wood piles or against the walls in damp basements, so removing Harborage will provide you the best LONG TERM control of this insect If you would like I can look up this for you but off the top of my head this is my suggestion, I am a true bugmann

---move him in with his mother in law--granny long legs