Repair of sprayed-on fireproofing
Repair of sprayed-on fireproofing
(OP)
I have a job where there were existing metal trusses with sprayed-on fireproofing. My electrical contractor come through and scraped off small areas of the fireproofing wherever he attached some new conduit supports.
Can anyone tell me what requirements (if any) for repair/replacement there are at each hanger location? I suspect there may be options for new sprayed-on or troweled-on firestopping, or perhaps a putty. Maybe do-nothing is OK.
Also, are there any specific requirements for the installer, or can my EC make the repair by himself?





RE: Repair of sprayed-on fireproofing
I'm still interested to see if anyone has any thoughts on this. I thought this would be an easy question.
RE: Repair of sprayed-on fireproofing
RE: Repair of sprayed-on fireproofing
Standard for Rapid Rise Fire Materials for
Structural Steel
JOHN HEYWOOD, P.E., CSP
SENIOR SAFETY ENGINEER
Saint Louis, Missouri 63125
RE: Repair of sprayed-on fireproofing
A. MATCH. It is important that the "same" system be included and not mixed. In fact, even manufacturers/vendors with similar products do not allow their own products mix and match such as the 2 part epoxy Thermo-Lag to correct the 1 component Firesorb or vice-versa. Remember that these are tested assemblies and as a rule tested assemblies do not usually have mixed systems.
B. PRECISION. On certain assemblies where there is a required fabric, you should inspect that damaged component and apply the same required combination of fabric, top coats, etc.
C. INSPECTION IS KEY. From experience I have been asked to patch monokote but upon closer inspection noticed the delamination process on bigger areas of the Q Deck/fluted metal decking. Adding even more weight to material already separating would have had bigger chunks fall off, and I walked on that repair because they didn't want to do proper patching repair. Instead they found some lesser cost inadequate entity to do this. The opening day showed particles all over the nice new crimson red carpet.
D. AVERAGES. There is a statistic in the industry and in some product manufacturers' books that 80 to 90% of the coated areas had to be perfect or average out to the "minimum required thickness".
E. INTEGRITY. Reputable providers of solutions offer proof of thickness of coatings by their applicators, and if you are in this for the long haul, there are some scientific devices on the market you can acquire that will help you do your own inspection of thickness. In my area of NYC where there are many tall buildings the inspectors are notorious for only inspecting the first one or two floors and not going any higher. Thus, the dishonest applicators pocket the difference of what they were paid for and what they didn't apply.