Is there a rule of thumb clearance we should allow between a protected member and adjacent construction? For instance, if we are using intumescent coating to protect a column, how much clearance should we give for the coating to expand? Can the adjacent materials be built tight to the member?
Hello,
The rule of thumb for our products will be a need for minimum 2" of clearance to allow for the intumescent fireproofing to char and form the proper thermal barrier.
Where this is impeded due to adjacent fire-resistance rated construction, we might be able to provide an alternative engineering judgment solution. For more information about the engineering judgement, please provide an architectural detail of the condition and a description of the issue to USSPEng@hilti.com.
Thank you,
Alex Hernandez
Fire Protection Testing and Projects
Thank you for your response.