Buying another router or power adapter which strenghts signal?

So guys i must solve this problem this summer cause of tourist cause i rent my house in summer.House is on three floors and i live with my family in the middle floor.Its a big house and in my room the signal sometimes(its away around 15meters from the dinning room where wifi router currently is) gets lost especially on mobile phone but its even worse on upper floor and the floor under us.Directly above and under the router its fine but if you go 10meters up or down from the direction of the router on the middle floor signal gets weak or completly lost(talking about first and third floor which are problematic).So lets go to the question.Is it better to make a bridge with a another router and how to do that?can i do it on my own or i need to call my internet provider or second option to buy a signal adapter which strengths wifi signal.Which option is best in terms of value and efficiency.As far as i read on internet first option seems expensive cause i need to buy a access point and new router?both?I hope someone will understand this mess i wrote.I live in Croatia just for direction.Thanks guys

 

I would personally go with a high end router. Never had good experience with those signal boosters / AKA repeaters, very flaky connection.

 

What kind of router do you currently have?

 

I'd make wired connection (ethernet or power line) between all the floors and have separate routers for all of them.
That way you would also have separate networks for guests and your family.

 

My coworker in IT recommends TP Link its a little pricey but it works really well. If I remember its the C9.

 

@

@Phoenix is that you ?

 

thanks for noticing this bro. I reported him and gave you a rep point. keep it up