THE shocking state of school buildings in Wales can be revealed today.
They are in such terrible condition the repair bill is estimated to be more than £765m.
Children's Commissioner Peter Clarke yesterday branded the state of many as 'shameful'.
And local councils are finding it 'next to impossible' to find the money to reverse the situation, said Anna Brychan, director of the National Association of Head Teachers Cymru.
Mr Clarke said it was extremely unlikely the Welsh Assembly would meet its 2010 target of every school being 'fit for purpose'.
Mr Clarke said, 'I've seen leaking roofs, sewers overflowing and no lifts in multi-storey school buildings.
'Children are being asked to sit in an environment which we would never ask adults to sit in.
'What sort of message is that sending out to them?'
His dismay follows a survey out today which reveals a backlog of repairs in 14 of Wales' 22 council areas totalling more than £500m. Averaged out for the whole of Wales, that adds up to a repair bill in excess of £765m.
The research, carried out by Times Educational Supplement Cymru, found the authority of Monmouthshire must find £130m to ensure its schools not only meet the National Assembly's fit for purpose standards, but also meet existing necessary repairs.
Parents believe the situation is putting Welsh schoolchildren in danger.
Just four months ago, pupils at Pen-y-Fai Church in Wales School, Bridgend, had to be evacuated because urgent repairs were identified.
Nicola O'Sullivan, mother of two children at the school, said, 'I'm worried the roof is going to collapse with the children inside, trapping and killing them.'
Last year, a report on Ysgol Coed y Gof at Pentrebane, Cardiff, found conditions were so bad they were potentially lethal. A building inspection found rainwater leaking onto electric cables and a floor which could have collapsed.
Graham Dalton, Cardiff County Council schools planning and development manager, said emergency repairs were the priority.
He said, 'We need to keep schools operationally safe and that means dealing with things like heating failures, roof leaks and fire precaution work.
'We are reactive because we can only afford to do work that we cannot avoid doing.'
Many Welsh schools still do not have adequate play areas, halls or dining facilities, and some still have outside toilets.
Councils get an annual allocation for school building improvement from the Assembly, which is ring fenced to be used only for that purpose.
They also get capital funding for building costs, but can spend this on other building projects such as roads.
An Assembly spokeswoman said yesterday, 'All authorities in Wales receive significant support for improvements to school buildings and facilities.
'We were committed to invest £560m between 2003 and 2007 to improve school buildings. This commitment has been more than met, with investment already standing at £629m.
'It is beginning to have an impact on the state of school buildings, though there is still significant work to be done.'
But Geraint Davies of NASUWT Cymru said, 'We should be ashamed that too many teachers and children are working in accommodation that dates back not to the last century but to the 19th century.'
Many councils are planning controversial school closures or amalgamations to cut surplus places and reduce maintenance costs.
Before Carmarthenshire began a £100m school modernisation programme, 38 schools there had mobile classrooms, 50 had no hall and 14 had outside toilets.
Councillors in Swansea plan to close Dylan Thomas Community School and could get £8m in a sell off with the money going to repairs.
In May, the council said just 12 Swansea schools needed repairs totalling £2,268,000 with Clydach Junior School needing £368,000 to replace 'sub-standard' existing buildings.