Fire rated treatment for existing wood

Log Out | Topics | Search Moderators | Register | Edit Profile

Author Message David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 707 Registered: 03-2002 Posted on Wednesday, August 23, 2006 - 02:19 pm:    The contractor installed plywood for backing and shear on our project. Now we come to find out that the wood needs to be fire treated. Does anybody know a field applied fire treatment for wood to make it fire rated? Ronald L. Geren, RA, CSI, CCS, CCCA, MAI Senior Member Username: specman Post Number: 316 Registered: 03-2003 Posted on Wednesday, August 23, 2006 - 02:29 pm:    What building code is in effect, and what is the construction type? David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 708 Registered: 03-2002 Posted on Wednesday, August 23, 2006 - 02:33 pm:    IBC 2003 Type II B construction Ronald L. Geren, RA, CSI, CCS, CCCA, MAI Senior Member Username: specman Post Number: 317 Registered: 03-2003 Posted on Wednesday, August 23, 2006 - 03:17 pm:    Yes, fire-retardant-treated wood is required. It is possible that you may have under-estimated the allowable area; therefore, you might be able to drop down to a Type III construction. Let's see if we can work towards that: 1. What are the occupancies? 2. Did you go separated or nonseparated uses? 3. What is the floor area of the largest floor? 4. How many stories (not counting basements)? 5. Is a sprinkler system installed throughout? 6. What percentage of the building's perimeter has a fire separation distance (distance from property line, center of road, imaginary line, etc.) greater than 20 feet? Jeffrey Wilson CSI CCS Junior Member Username: wilsonconsulting Post Number: 2 Registered: 03-2006 Posted on Wednesday, August 23, 2006 - 06:37 pm:    I recently had a client that selected intumescent coatings for application on existing wood to comply with requirements for non-combustability. We spec'd products by Flame Control Coatings LLC, Niagara Falls NY (716-282-1399). David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 710 Registered: 03-2002 Posted on Thursday, August 24, 2006 - 12:46 pm:    Ronald, I appreciate your help but think that we are too far down the line to change construction type classification. I proposed the question to the project manager anyway. Jeffrey, I have investigated all sorts of coatings. They reduce the surface flame spread but not the burning characteristics of the wood itself. This may not word because plywood is not an exposed finish but instead will be buried in the wall and will have untreated back side, edges and inside. We may have end up having to remove the untreated plywood and install treated plywood or install a layer of 5/8 inch Type X gypsum board. If we go the gypsum board route we will have to redetail door frames and transitions. Ronald L. Geren, RA, CSI, CCS, CCCA, MAI Senior Member Username: specman Post Number: 318 Registered: 03-2003 Posted on Thursday, August 24, 2006 - 12:55 pm:    Actually, it's never too late to change. The building can not be classified any higher than the type for which it meets the minimum requirements based on occupancy (Section 602.1.1). In otherwords, if it can be classified as Type III, A or B, construction, then you can not be required to comply with the more restrictive requirements of a higher construction type. If, during construction, the jurisdiction can make you add stuff that they missed during plan review, they should also allow you to reduce the classification if you do find that it does comply with those minimum requirements. David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 711 Registered: 03-2002 Posted on Thursday, August 24, 2006 - 02:37 pm:    Contrary to what I just said above, I think that I have found the product! FireFree 88 http://www.firefree.com/ Has anybody had any experience with this product?