Roland Garros tournament director Guy Forget says the delays caused by the weather in the opening days of the 2016 French Open re-emphasise the need for a roof on Court Philippe-Chatrier.
Inclement weather in Paris heavily affected proceedings on day one on Sunday and further rain pushed back the start of play on Monday.
Wimbledon's Centre Court has a roof, with one to follow at Court One by 2019, while Arthur Ashe Stadium at Flushing Meadows, home of the US Open, will have one in place in time for the final slam of this year.
By contrast, Forget says work to put a roof on Court Philippe-Chatrier will not be completed until 2020.
"When you go through two days like this you realise the importance of having a roof over your courts," Forget said.
"I think it's a question of respect to the crowd, to the people, and to the players that are waiting hours and hours in the lounges, in the locker rooms.
"To the fans out in front of the TV that love to watch tennis, they have been waiting for a year to watch clay court played on TV.
"We wait and wait and wait and wait. While Wimbledon, you know, Melbourne, and New York now have the new roof, you know, we'll have to wait until 2020 to have ours.
"Although we have talked about it, the project started many years ago. So, you know, for that matter, I think this is the perfect example of why we need to get bigger, so the stadium is not as congested as it is today [Monday]. We need to modernise our facility for these reasons. It's a necessity."
Asked how confident he is of work being completed for 2020, Forget replied: "Well, regarding the roof, we're pretty confident, because the works have already started since two years in the stadium. It's not necessarily visible right now, but we have made progress.
"And as soon as the tournament will be over, a few days later a lot of people will come on the stadium again to go on with the work. It's an ongoing process which will take us in 2020 where hopefully everything will be done. And the roof is actually the last piece of that puzzle."