But it was only when tragedy struck that it was brought home to them how dangerous the condition is.
The 16-year-old, from Sherburn-in-Elmet, collapsed and passed away while he on a shopping trip on September 2.
He had been out buying clothes for college course which he had been set to start in a few weeks after celebrating his GCSE results this summer.
Now his elder brother Ashley Flay is determined to raise awareness of the dangers asthma in his brother’s memory.
Mr Flay has chosen to support a charity which started by another Yorkshire family who was struck by a similar tragedy when they lost their 10-year-old son to asthma.
Breathe for Cameron was set up by the family of Cameron Good, from Hull, who passed away after having an asthma attack during football practice two years ago.
It works to put emergency inhalers into schools and raise awareness of the dangers of asthma. Mr Flay has set the goal of raising £2,500 for the charity and is already close to three quarters of the way to meeting that target through donations on his Justgiving.com website page.
He said; “Jack was out shopping for clothes in Selby for the college course he would have been starting in a few weeks when it happened.
“He collapsed, and was not able to be brought back to us.
“It has completely stunned us.
“We we very close he was my little best friend. He was going to college to study cyber security. He was really bright, a little whizzkid. I need to turn my grieving into something positive.
“I am trying to raise the profile of Asthma. People don’t realise that it is a silent killer.
“I have found an amazing little charity called Breathe for Cameron, who I will be working with to raise as much awareness as possible, get education into schools and workplaces and into the general public. If I can save just one life in the loss of our beautiful Jack, then his life won’t have been lost in vain. We cannot and must not let another family go through the pain that we are suffering.”
Craig Salter, Cameron’s step dad said: “We would like to be in a position where we never had to hear from people who have gone through this as we did but at the same time it so humbling that Ashley has asked to help our charity.
“We hope we can help his family in the months ahead.”
Mr Flay’s fundraising for the charity can be supported at https://www.justgiving.com/crowdfunding/savelivesforjack