Call Blazeframe: 425-869-2811


Q) “Is sealant required over mineral wool as jobsite conditions are different than lab conditions where mineral wool can be stuffed perfectly and this won’t happen on jobsite so there won’t be as good an air seal…”

A) All UL 2079 testing occurs in same manner and tested wall assemblies are built in same conditions whether “friction fit only” or “stuff and sealant” assembly is tested. An optional L-rating (air/smoke leakage) test provides measured leakage certification and describes how voids and joints are installed to meet compliance with each individual certified/listed assembly. Typical requirements of mineral wool from “stuff and spray” listings:

  • Packing Material — Min 4 pcf (64 kg/m3)density mineral wool batt insulation cut to the shape of the fluted deck, 50 percent larger than the area of the flutes and compressed into the flutes of the steel floor units above the ceiling runner as a permanent form….
    • Forming Material*—Plugs — As an alternate to Item 3A, preformed mineral wool plugs, formed to the shape of the fluted floor units, friction fit to completely fill the flutes above the ceiling runner…..
  • Proper application of flute fill materials for any system requires a “complete fill of flutes”
  • It is neither Code Compliant nor Responsible to allow poor quality controlled “semi-installed” or “loose fit” mineral wool with pass through gaps and cover over with sealant. Sealants are “sacrificial” coating and if not completely backed by mineral wool would burn through on both sides of assembly compromising life safety construction.
  • UL third party certifications list methods where “friction fit” installation of only mineral wool with no sealant achieve lowest L-rating available (less than 1 CFM/lft) with up to level III (seismic) certification meeting code requirement of “…less than 5 cfm/lft…” (see ICC Section 713.6)

BlazeFrame Advantage in Jobsite application:

  • mineral wool flute fill installed prior to bottom track, studs, gypsum, and MEP obstructions replicates lab certified assemblies with no increase in difficulty of installation
  • both sides of BlazeFrame top track and flutes can be accessed providing unobstructed immediate quality control for flute fill application/joint completion and inspection

Mastic Spray Considerations in Jobsite Application:

  • wall must be completely constructed (typically MEP obstructions also exist) before application
  • increased installation difficulty vs. lab certified assemblies with addition of having to work around obstructions and wall (reduced leverage to insert wool and obstructed access to spray sealant coating in consistent, complete, and required amounts)
  • increased difficulty to quality control application around and behind obstructions both sides of wall
  • increased difficulty to access and provide accurate inspection behind obstructions (both sides)

Q) “How are small gaps that may occur between BlazeFrame and “uneven” substrates where BlazeFrame isn’t seated dealt with to provide air seal….”

A) Use of a “sliver” of mineral wool or small bead/dab of caulk to fill any gaps will provide air/smoke seal prior to any elevated temperature exposure. Elevated temperatures above 325 deg F (425 deg F is when cotton fibers ignite) will cause intumescent on BlazeFrame to expand (up to 35 times larger) and swell in all directions covering over and sealing any gaps.

Detail callout from UL listed BlazeFrame assemblies:

  • Forming Material* — Min 4 pcf (64 kg/m3) density mineral wool batt insulation cut to the width of the ceiling runner and to the shape of the flutes and compressed 33 percent in thickness, installed into flutes above ceiling runner. Joints with nominal gap greater than 1 in. (25 mm), mineral wool batt insulation shall be cut to a width not less full thickness such that entire fluted area above thickness of wall is filled with mineral wool. When gaps are present above ceiling runner at steel deck, seams, or embossments in steel deck valleys, mineral wool batt insulation shall be used to seal each gap to attain L Ratings.
  • Fill, Void or Cavity Material* — Sealant — (Not Shown) – As an alternate to sliver of mineral wool batt insulation in Item 3A, sealant may be used to seal each gap at steel deck, seams, or embossments in steel deck valleys to attain L Ratings.

BlazeFrame Advantage in Jobsite application:

  • Applicator installing mineral wool “deck plugs” can stuff sliver of mineral wool (if necessary) completing “head of wall” during same mobilization
  • As an alternate in lieu of mineral wool sliver, Applicator may carry a tube of caulk in lift which can be applied (if necessary) completing “head of wall” during same mobilization

Q) “Are caulks/sprays allowed to be in contact with BlazeFrame materials when a “penetration” goes through them…”

A) Current manufacturer recommendations on “chemical compatibility” are that any “non-solvent” based materials can be in contact with BlazeFrame intumescent material with no adverse or degrading effects. Materials such as caulks/sprays, fire-proofing, drywall “mud”, paint, etc… are acceptable.

Q) “What brands of penetration sealants are acceptable…”

A) Accepted water based penetration sealant brands currently on file with BlazeFrame as being chemically compatible:

  • Metacaulk: 1000, 350i, MC 150+, 950, 1100, 120, 1500
  • Biostop: 500+, 350i, BF 150+, 700, 750, 800
  • Flamesafe: FS 1900, FS 900+, FS3000,
  • USG: Type AS

Other brand names may be used provided that manufacturer of specific brand can provide verification of materials being “non-solvent” and will allow/warranty use of them in applicable conditions.

Q) “Will uncoated mineral wool release fibers….”

A) Mineral wool by definition is: “a mass of fine, intertwined molten rock fibers with a typical diameter of 6 to 10 micrometers. Mineral wool may contain a binder, often food grade starch, and an oil to reduce dusting.”

  • Having interwoven fibers in a “stagnant” condition (similar to dust/particulates accumulated above mechanical ducts, pipes, cable trays, etc…) and located in position (friction fit into a fluted opening where no contact or dislodging occurs fibers will stay intertwined.
  • Properly installed “friction fit” mineral wool flute fill is all that is required to meet current code requirements and provide certified lowest achievable leakage rating and up to 3 hour fire protection
  • Application of sealants over wool such as sound or fire caulk, primer, paint, etc… will not affect life safety and can be applied over mineral wool as additional “fiber sealant” protection if so desired

BlazeFrame Advantage:

  • application of “additional” (not required) sealant can be done without difficulties of working around obstructions and wall assemblies
  • installing mineral wool and applying any additional “coating” directly after BlazeFrame installation and before framing/MEP obstructions allows for improved access, safer conditions, ability to apply consistent thickness, with improved quality control and inspection.

Q) “What about STC ratings for BlazeFrame and use in non-rated “sound/smoke” walls…..”

A) BlazeFrame joint protection has been third party certified to maintain similar STC ratings achieved with the use of caulks and has on file additional testing with “perpendicular mineral wool only” fluted, BlazeFrame Flute Cover (no mineral wool) parallel, and 16ga framing conditions.

BlazeFrame Advantage:

  • Non-rated “sound/smoke” joints experience same deflection as rated walls and BlazeFrame movement capability, no fatigue, and joint protection remain same for life of assembly
  • BlazeFrame provides solutions where acoustical sprays (not typically third party certified) can’t provide required protection as most are limited 12% to 25% movement capability requiring very large installed joint (if possible) to meet specifications or codes

Blazeframe Industries

2509 152nd Ave NE
Bldg. 16, Mezzanine A
Redmond WA, 98052
Phone: 425-869-2811
Fax: 425-869-2300

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