"It's to shade our 5-year-olds and now we'll be using our school funds to pay for another."
St Patrick's had hosted a number of fundraising events during the past few months to buy sports equipment for the students, something they were looking forward to.
"We were also going to buy our juniors some equipment for their play-based learning, but we can't buy that now. We have to replace the shade sail and they're not cheap.
"Someone has taken it for their own personal use, probably for their own family. So, we wish them a very Merry Christmas."
The school was working with the police to see if the sail could be located.
"The act is quite brazen and very disappointing. It's a pity people steal from children.
"We haven't downplayed it, we told them that these things happen and that we will replace it. But they couldn't believe that someone would steal from them."
Camberley School in Hastings was also hit this week. A window was smashed and graffiti discovered on its public toilet walls.
The school reached out to the public via their Facebook page, saying that Heretaunga and Camberley kindergarten also had their buildings damaged by local primary school students, which was "really sad".
"We have had a korero with our tamariki regarding respecting our schools and kindy and are asking that whanau respect our tikanga by not letting their tamariki come to school unsupervised out of school hours."
A spokesperson from the school did not want to comment to Hawke's Bay Today.