Have you ever stood at a school fundraising BBQ wondering, "Why am I doing this?"

You're not alone.

Fundraising for schools is such an accepted part of our society that it rarely attracts critical attention.

No-one knows just how much fundraising props up our public education system. It is not recorded in any financial system and academics have not focused on it in their research.

And it seems that few care — certainly not those with their hands on the school funding purse strings.

We surveyed 175 Australians and spoke to experts to try to find out what's going on.

No-one knows how much fundraising props up the public education system. ( Supplied: Nova Inkpen )

The good, the bad, the ugly

For Kelly, a 40-year-old mother of three, fundraising was a link to her children's primary school in regional NSW.

"I have made many friends through being part of volunteering and I love being part of the school community spirit," she said.

Yet for many parents, there are downsides. The pressure can be high — followed by the guilt when it feels like you can't do enough.

"You're not obligated to get involved, but if you don't, you're made to feel guilty for not digging deep," one mother in regional Queensland said.

Claire, a 44-year-old mother of two public primary school students in Darwin, told us it seemed like fundraising activities just extracted funds from parents via raffles, walkathons and other donations.

"It is sort of like a compulsory contribution but with lots more work for the fundraising organisers," she said.

While fundraising is often seen as a "bringing together" of a school community, this is not always the case and the emotion can be intense.

"Our P&C meetings can be brutal. A clash of opinions or personalities has managed to bring out the very worst versions of members," said a 42-year-old mother of two at a regional NSW public primary school.

Fundraising for the basics

Volunteers often feel compelled to continue because they are fundraising for basics, not luxuries.

Survey respondents said it was common to fundraise for teaching resources, technology equipment or equipping outdoor play spaces. Some reported raising money for repairing toilets and clearing unsafe trees.

A 46-year-old parent said the need for fundraising at her two children's Sydney primary school was urgent.

"At our school we had to purchase the bubblers. The children were getting sick due to bird poop in the bubbler area. This is something I consider a basic need, access to clean water, but the school did not agree."

So why don't we know more about fundraising?

The best data available is a small survey showing that parent groups in 87 ACT public schools raised a combined $5 million in 2016-17.

Applying this average of about $57,000 per school would mean that fundraising contributes $380 million to Australian public schools each year.

Is this figure robust enough to use with confidence? No. It's from one region and the body who conducted it, the ACT P&C Council, cautioned against it being interpreted too broadly. But it's a start.

This figure fits with a survey conducted for this story. A third of respondents said that their school raised tens of thousands of dollars each year — some said they raised more than $100,000.

Cakes stalls and sausage sizzles remain strong fundraisers for P&C groups throughout Queensland. ( ABC Open: June Perkins )

The education ministers and their departments that we approached couldn't quantify how much fundraising contributed to the overall school budget.

A spokesperson for Federal Education Minister Dan Tehan said: "P&C and other parent fundraising data is not collected by the Australian Government Department of Education."

"Fundraising occurring in schools is a matter for a school's Parents & Citizens council," an ACT Education Directorate spokesperson said — typical of responses from states and territories.

The fact that this figure is not known — or even sought — speaks of a lack of caring about how much our education system is being propped up by fundraising.

It also shows a lack of acknowledgment for the hard yards that parents and teachers are putting into raising money for items needed for their children's schools.

An unequal division of labour

Even if we had a robust fundraising dollar amount, this would not capture the in-kind labour and contributions that the not-for-profit world was increasingly trying to quantify.

Most volunteers are from the group who do the highest rates of unpaid domestic labour and already feel the effects of the gender pay gap — women.

In the survey conducted for this story, a quarter of respondents estimated they had spent between 100 and 500 hours on tasks related to school fundraising in the past year.

That's up to 10 hours every week, the equivalent of a part-time job.

Volunteering Australia estimates that in 2016, nearly 18 million volunteer hours were dedicated to the overall cause of education.

That's almost one hour per Australian citizen, but you can bet your democracy sausage the labour was not evenly distributed.

Volunteering Australia estimates that in 2016, nearly 18 million volunteer hours were dedicated to the overall cause of education. ( ABC News: Penny McLintock )

That was the experience of a 36-year-old mother of a 10-year-old at a small public primary school in Hobart.

"The burden of fundraising fell on a disproportionately small number of people, all of whom went well above and beyond what is reasonable to expect or ask of parent volunteers," she said.

Many are incredibly burdened by their contribution of time, expertise and money.

A 45-year-old mother of two at a public primary school in Melbourne found herself coordinating a major fundraiser.

"I won't be back to do another one. The parents who did it before me two years ago have completely stepped away … I think that speaks volumes," she said.

For at least one parent, a 47-year-old mother of one at an Adelaide public primary school, the time has come to bow out of fundraising.

"The stress of it all has become too much for me and my family," she said.

Beneath the silver lining

Fundraising, so often presented purely as a good news story, increases existing inequities.

Some schools, courtesy of their demographics, simply find it easier to fundraise larger amounts of money. And wealthier schools tend to be surrounded by businesses that can afford to donate larger items.

A teacher from a public primary school in Perth sums up the issue this way: "My low SEI [socio-economic index] school is lucky to raise $2,000 in an amazing year," she said.

"Yet we see high SEI schools raising $60,000 or more from a quiz night."

Schools take on a carnival atmosphere with fundraising stalls on ACT election day. ( ABC News: Clarissa Thorpe )

Research from last year showed that in one region, the "Fees, Charges and Parent Contributions" category of My School finance data was more than four times higher in the most advantaged schools compared with the least.

If fundraising — figures of which, for most public schools, are not included in any of the My School data — was added into the equation, the gap would be even higher.

"This is a problem," said lead researcher Emma Rowe, "because we have a very unclear understanding of the amount of private income different schools are generating and the financial gaps between schools."

Fundraising is a small portion of the total school funding picture — after all, the best estimate of $380 million is less than 1 per cent of the $43.7 billion spent on funding public schools in the same year — so this may be why it slips under the radar.

But with parents and others busting their butts to raise it, it clearly plays an important role in individual school communities.

Without a full picture of fundraising, we can't understand the funding challenges facing the public education system.

Vivienne Pearson and Margaret Paton are freelance journalists.

This reporting was funded by the Walkley Public Fund and the Judith Neilson Institute for Journalism and Ideas through a Walkley Grant for Freelance Journalism.