Ran 4x10 rift white oak prefinished Class A FR MDF panels today for a hotel lobby wall; 3 mm shadow reveals CNC’d with a 1/8 in downcut at 18k rpm stayed clean and the cut edges took the FR sealer evenly… Anyone else getting AHJ sign-off on these without an extra intumescent topcoat, and how are you handling edge exposure at access panels?
Same here — no extra intumescent when the full finish system matches the listing; our AHJ accepted Roseburg Arreis FR veneer panels (E84 Class A) and we flood the 1/8-in @18k cut edges with the OEM FR sealer per https://www.roseburg.com/product/arreis-fr/.
And we’ve gotten sign-off without extra intumescent when the finish schedule exactly matches the listing — include the cut-edge sealer data and a one-page “field touch-up” procedure in the submittal. For access doors with a 3 mm reveal, we slip a 1/16 in black anodized aluminum U-cap over the panel edge and mount the door on a knife-edge frame with VHB, so the MDF edge never shows; at the CNC we do a final.010 in pass at 18k rpm to avoid fuzz. @s_perry34 how’s your AHJ on metal trims at reveals?
On access panels, I micro‑chamfer the cut, wick thin CA to lock fibers, then two wet passes of the same FR edge sealer and cap the reveal with a 1/2 in anodized aluminum trim so the inspector doesn’t treat it as an “exposed edge”; @f_andrews123 have you had pushback on the CA step or do you just build sealer?
We’ve gotten sign-off when we mark the back with the listing number and include the mfr’s finish bulletin pulled from UL Product iQ (https://productiq.ul.com). For access doors I rabbet the backside about 10 mm and bond a 0.6 mm veneer return so the core’s buried, then take a 0.2 mm climb “kiss” pass around the reveal at about 12k to prevent fray. Would your AHJ accept a small veneer return like that?