Thank you, but to be clear, do you mean the wifi speed, and if so will it reduce from the second extender only or affect the whole system?
Daisy chaining wifi extenders is not desirable, speed reduces in the order of 50% each time you add one. Having said that, you can use multiple extenders providing each one has direct access to the hub.
Rubbish signal in, rubbish signal out. By the time you want to use them you are probably at the outer reaches of your wireless signal so by extending it again you are using an even weaker signal to start with.
If you have to extend your wireless network you would be better to either use a Mesh system or the cheaper option of wireless powerline adaptors. The transfer the broadband signal via your electrical circuit and then act as a wireless access point.They might not be suitable depending on the electical circuits in your property.
Thanks to everyone who replied.
To sum up, it seems it's not a good idea!