Objectives Blue-collar workers are a recognised priority for tobacco control. Construction workers have very high smoking rates and are difficult to study and reach with interventions promoting smoke-free workplaces and cessation. The objectives of this study were to explore the smoking-related social climate in the North American residential construction sector and to identify potential barriers and facilitators to creating smokefree worksites.

Methods The data source used was a popular internet forum on home building. Participants included a broad and unselected population of employers, employees and freelance tradespersons working in residential construction. The forum archive contained 10 years of discourse on the subjects of smoking, workplace secondhand smoke and smoking restrictions on construction sites. Qualitative data analysis methods were used to describe major and minor discussion themes relevant to workplace smoking culture and policies in this sector.

Results Participants described considerable tension between smoking and non-smoking tradespersons, but there was also much interpersonal support for cessation and support for non-smokers' rights. Employers and employees described efforts to make construction sites smoke free, and a movement towards preferential hiring of non-smoking tradespersons was discussed. Board participants wanted detailed scientific evidence on secondhand smoke exposure levels and risk thresholds, particularly in open-air workplaces.

Conclusions Experience with success of smoking bans in other challenging workplaces can be applied to the construction sector. Potential movement of smokers out of the workforce represents a challenge for public health systems to ensure equitable access to cessation supports and services.