Is this a good idea

Should i pause the standard shield when i doing a antispyware scan of my system?

Someone will say yes, to avoid double scanning at the same time, scan speeder.
Others will think: never disable the last layer protection, your antivirus. To scan, archive files are opened and, if the antispyware tool does not detect the extracted files, something bad could occur and you’ll get infected.

I personally pause standard shield whilst doing any other anti-virus, anti-adware/spyware scan, this may avoid conflict between two active scanners. It also avoids duplicate scanning as avast will respond to the other scanner opening files, etc. this should also speed up the scan.

Archive files can be scanned, even opened and they are still inert until the payload file inside an archive is run/executed, not something that an inspection/scan does.

Just ensure you aren’t connected to the outside world (internet) at the time.