Poor standards and dangerous practices were found at nearly half of the building sites visited by the Health & Safety Executive (HSE) during a month long safety drive.
During a nationwide campaign, the HSE visited 2,607 sites where refurbishment or repair work was taking place, looking for good site order, sound structures and basic welfare facilities.
Inspectors found basic safety standards were not being met on 1,105 sites.
On 644 sites, practices were so poor that enforcement action was necessary to protect workers – with 539 prohibition notices served ordering dangerous activities to stop immediately and 414 improvement notice issued requiring standards to improve.
The most common problems identified included failing to protect workers during activities at height, exposure to harmful dust and inadequate welfare facilities.
Heather Bryant, HSE’s chief inspector of construction, said: “It is disappointing to find a significant number of sites falling below acceptable health and safety standards, where our inspectors encountered poor practice this often went hand in hand with a lack of understanding.
“Through initiatives like this we are able to tackle underlying issues before they become established and we will continue to work with the industry in an effort to drive up standards.
“However those who recklessly endanger the health and lives of their workforce can expect to face tough consequences.”