Hi Chronzam,
I strongly suggest that the preloader is instead removed all together!
There are some that argue that it’s necessary to delay the content as it would confuse the visitor if their connection is slow, as often is the case in India for example.
I would say that it is only an excuse for the developer to charge more. Especially when the connection is slow causing that the visitor maybe can’t use your site at all.
https://kryogenix.org/code/browser/everyonehasjs.html
I suggest you use Javascript to both show and remove the preloader instead of default show it at page load!!!
You greatly annoy those visitors that have Javascript restricted at new sites as they can’t decide if the site is trustworthy or not and hesitate to enable Javascript and take a risk just to find out.
They may leave and judge your site as unfriendly and maybe question why it is necessary to use Javascript just to view the site and suspect that the site needs it in order to attack the visitor.
I for one discourage from using sites that behave in that way. 