The Mica Action Group has sent a 13-page document to the Minister for Housing, listing dozens of questions the group says have yet to be answered or which need more clarity or detail.
The group, which represents thousands of people whose homes are crumbling due to defective blocks, says the document is in relation to the Revised Defective Concrete Blocks Scheme.
PRO for the group, Michael Doherty, said the list of questions was sent to Minister Darragh O'Brien "In the absence of homeowner reps being invited to form part of the Expert/Stakeholder Groups working on the Revised Defective Concrete Blocks Scheme" and he called for a more collaborative approach to make the scheme work.
"The scope and quantity of questions as yet unanswered underlines the scale and complexity of the Defective Concrete Blocks Scheme," Mr Doherty said.
"It also reinforces the urgent need for a clear and detailed understanding of every phase by Government, to ensure efficient and successful operational outcomes, as well as the comprehensive overview required to underpin effective legislation."
Many of the questions which the group is asking relate to the testing of homes, building regulations, foundations, geographical eligibility and exclusion from the scheme.
They are seeking a definition of the term "damage threshold" and ask questions about the demolition of homes and disposal of materials.
The document seeks clarification on emergency funding and temporary accommodation "given the severe shortage of rental accommodation".
It also asks about taking into account personal circumstances, including physical and mental health.
Mr Doherty said that during last week's storms, he had homeowners crying on the phone, not knowing where to turn.
"They were fearing their house was going to collapse on top of their family," he said.
"They were genuinely terrified. There can be no more delays. The revised scheme needs to be right first time and we urge Government to put in place a structured process of immediate, direct and continual engagement with homeowner reps without delay.
"There is a huge body of expert knowledge amongst homeowners and also key personnel in the local council, who live and breathe these issues every day. We understand the intricacies of what works and what doesn’t. We have more at stake than anyone in this process, so it seems mad that we are not in the room with the other parties."
Mr Doherty said that there have already been "too many deadlines" set by Government that have come and gone.
"Time is a luxury we don’t have. We have families living in perilously unsafe homes," he added.
A report on construction costs by the Society of Chartered Surveyors of Ireland in relation to the revised scheme is due to be submitted to the minister next week.
