Propping the door open

[Spaghetti]

I'm sure there must be a simple solution to this.... our conservatory doesn't have any catches on the doors to hold them open so we are currently propping the door open with a bit of railway sleeper. Not ideal with young children around and it's scratching the door.

My OH won't entertain putting any hooks on as he says they have to be screwed into the door and will damage it.

Can anyone suggest an ingenious way to keep the door open?

[welsh brickie]

You can purchase stays from a double glazing company which screw
into the rebate at the top of the door simple to fit but if your unsure ask advice from the company.