19. Glu-lam Alternate Methods Letter.pdf
1402 Third Ave, Suite 200 / Seattle, WA 98101 / T 206.652.0722 / F 206.340.2266 / www.salus.archi
June 18, 2018
Leif Bjorback
Linda Thornquist
City of Edmonds, Development Services Department
121 5th Ave N
Edmonds, WA 98020
Subject: Edmonds Recovery Center – Northpoint Recovery
Remodel of Edmonds Facility - 7416 212th Street SW
Alternate Methods for providing glu-lam fire rating - Letter of Rationale
Permit # BLD2018-0447
Dear Leif
This letter concerns Beck & Associates Northpoint Recovery comment #19a:
“Provide documentation that demonstrates that all of the glulam beams
maintain a 1-hour rating, consistent with the floor-ceiling assembly rating. If
this cannot be provided, an alternate means of providing the 1-hour rating
at the glulam beams is required to be provided”.
The Code Issue:
Since there does not appear to be a rated listing for glu-lams we cannot met the code
prescriptively, we are submitting an “alternate method of construction (IBC 104.11)”
for your review.
Code requirements for Floor Assemblies in a Type VB.
This building is a VB fully sprinklered. The Occupancy is I-1 Condition-2
IBC Section 420.3 Horizontal Separation “floor assemblies separating sleeping units
from other occupancies contiguous to them shall be constructed as horizontal
assemblies in accordance with Section 711.
IBC Section 711.2 Horizontal Assemblies shall comply with Sections 711.2.1 through
711.2.6.
IBC Section 711.2.3 Supporting Construction shall be protected to afford the
required fire-resistant rating of the horizontal assembly support.
Exception (to 711.2.3) in buildings of VB construction the construction supporting the
horizontal assembly is not is not required to be fire-resistance rated at the following:
Exemption#2 – Horizontal assemblies at the separation at the separation of sleeping
units as required by Section 420.3.
Code Requirement (711.2.3)for floor rating: This part of the code appears to allow a
non-rated floor assembly.
Mr. Leif Bjorback
June 18, 2018
Page 2
Code requirements for Floor Assemblies with smoke and fire partitions
The IBC requires both 1-hour smoke barriers (Section 709) and fire partitions (Section
708) in this project.
In Sections 708.4 Continuity: “fire partitions shall extend to the underside of the fire
resistance-rated floor or roof assembly”.
In Sections 709.4 Continuity: “smoke partitions shall extend to the underside of the
fire resistance-rated floor or roof assembly”.
Code Requirement (708.4 and 709.4) for floor rating: This part of the code appears to
require a rated horizontal assembly.
Glu-lam Fire Resistance:
We looked at what sort of fire resistance the glu-lams have:
- To determine strength of the glulam after charring has occurred, we used the APA
Engineered Wood Association Technical Manual: “Calculating Fire Resistance of
Glulam Beams - EWS Y245B”. (APA is located in Tacoma WA. Phone: #253-565-
6600)
- Per the Technical Manual, the char-rate thru the glulam is at 1/40” per minute or
1.5” of glu-lam per 60 minutes.
- Per the Technical Manual, the char-rate thru the glulam is at 1/40” per minute or
.75” of glu-lam per 30 minutes.
Glu-lams that support the second floor:
The glu-lams that support the second floor are 6 ¾” wide x 31” high. However, only
the lower 17” of the glu-lam are exposed because the adjacent 1-hour rated floor
assembly (see attached detail SD2.01) covers the rest of the glu-lam.
Greg Lee of ABKJ Structural Engineers (See attached letter dated 6-18-2018)
evaluated the exposed 17” of this glu-lam and found that the 2nd floor glu-lam can
handle 30 minutes of charring and still support unfactored (service level) loads at the
factored or ultimate stress levels.
Since there isn’t a UL listed method to provide a rated enclosure for the additional 30
or 60 minutes of coverage, we propose three alternate method options:
Brian Perry (Product Engineer for Albi Protective Coatings) attached letter
(6/15/2018) states: “Based on the technical Note #EWS Y2445B from the APA –
Engineered Wood Association, the fire resistance rating up to 1-hour can be
calculated for glu-lam members. This method is recognized by the International
Building Code. Based on the calculations, the 6 3/3” x 31” glu-lam has a fire
resistance rating of 58 minutes and the 5.5” x 27” glu-lam has a fire resistance rating
of 53 minutes. These calculations were made assuming the beams would be carrying
100% of their maximum design load.
Mr. Leif Bjorback
June 18, 2018
Page 3
Glu-lam Fire Resistance Conclusion:
Based on Greg Lee and Brian Perry’s letters, it appears the exposed glu-lams will not
be able to provide a 1-hour fire resistance. However, the glu-lams will provide at least
30 minute or greater resistance. The following are (3) Options for an “alternate
method of construction (IBC 104.11)” to comply with the intent of the provisions of
the code.
Of the three Options below, Salus prefers Option #1 for ease of assembly and as it is
the least expensive.
OPTION#1 (see attached detail) - Provide (2) layers of 5/8” Type-X GWB on ½” metal
clips on the three exposed sides of the glu-lam. This assembly matches the one-hour
rated ceiling assembly (UL L570) shown on Detail 7/A9.01 which is located on either
side of the glu-lam. (See attached Detail SD2.02)
OPTION #1 Rationale: If a fire (in a fully sprinklered building) can penetrate (2) layers
of GWB enclosing the glu-lam, it would also be able to penetrate the (2) layers of GWB
in the rated floor assembly on either side of the glu-lam.
If (2) layers of rated GWB are sufficient for the 1-hour ceiling assembly, then (2) layers
of rated GWB and the 30 minutes of fire resistance provided by the glu-lam should be
sufficient to provide the lower 17” of glu-lam with at least 60 minutes of protection.
Sealant where glu-lam meets the horizontal GWB assembly:
Spec seal-SSS or LCI Sealant sealant will be installed. (See attached “engineered
Judgement Firestop Detail” NS14918024)
This sealant can also be applied when the glu-lam is enclosed with rated GWB.
OPTION#2:
Provide 1-hour shaft wall (UL Des U469) on the on the three exposed sides of the glu-
lam. (See attached detail SD2.03)
OPTION #2 Rationale: Rated shaft wall is used thru-out this country to provide fire
rated protection and should be more than sufficient to provide 60 minutes of fire
resistance for the glu-lams.
OPTION#3: Provide 40 mils WFT (28 mils DFT) of Albi Clad FT of intumescent paint
over the exposed sides on the three exposed sides of the glu-lam. (See attached
Detail SD 2.04).
OPTION #3 Rationale:
- See attached Albi Brochure for basic product information.
- See attached letter (dated 6/15/2018) from Brian Perry (Product Engineer for Albi
Protective Coatings) which states:
Mr. Leif Bjorback
June 18, 2018
Page 4
Option #3 Conclusion: Combining 40 mils of intumescent paint with the at least 30
minutes of fire resistance provided by the glu-lam should be more than sufficient to
provide 60 minutes of fire resistance.
Please review these three options and let us know if you have any questions.
Thank you for your consideration.
Douglas McNutt Principal
1402 Third Avenue, Suite 200
Seattle WA 98101
Cell: 206 605-5597
Direct: 206 957-1906
Office: 206 652-0722
Fax: 206 652-0720
Email: douglas.mcnutt@salus.archi
Web: www.salus.archi
Encl: Details SD2.01, SD2.02, SD2.04, SD2.04, STI-Engineered Judgement, Calculating
Fire Resistance for Glu-lams, Greg Lee Letter, Brian Perry-Albi Letter, Albi Fire proofing
Brochure
C: R. David Frum, FAIA, ACHA
Z:\16029 Northpoint Recovery\Docs\06.01-MunicipalReview\Permit Responses\Alternate Methods Letter\Northpoint - Alternate Methods letter_6-18-2018.docx
PROVIDE 2 LAYERS OF 5/8"
TYPE X GWB AT UNDERSIDE OF
EXISTING I JOISTS
NEW 1 1/2" THICK CEMENTITIOUS
TOPPINGS OVER 5/8" PLYWOOD
7/8" RESILIENT CHANNELS
EXISTING TJI
FIRE/SMOKE SEALANT AT BOTH
SIDES COMPLYING WITH UL 2079
EXISTING GLULAM
SECTION
17
"
E
X
P
O
S
E
D
EXPOSE ALL SIDES OF GLULAM
REV TYPE:
DATE:
JOB #:
1402 Third Ave.
Suite 200
Seattle, Wa
98101
(206)652-0722
RATED CEILING AT GLULAM
EDMONDS RECOVERY CENTER
NORTHPOINT RECOVERY
SD2.01
Author
06/18/18
16029
June 18th, 2018
Mr. Douglas McNutt
Principal
Salus Architecture
RE: Charring Calculation for Existing GL Beam
Douglas,
At your request, I have reviewed the carrying capacity of the Glu-Lam (GL) beams based on a 1/40”
charring rate per minute.
I found that the exposed area of the 2nd floor 6 ¾”x 31 1/2” GL beam can handle 1/2 hour of charring
and still support unfactored (service level) loads at the factored or ultimate stress levels. This is apart
from any consideration of any of the three applied options: 2-layers of GWB protection (which
normally is counted as 1-hour rating) below the ceiling, shaft wall, or intumescent paint, either of
which will increase the over-all resistance.
I also checked the roof 5 1/8”x27” GL beam capacity if charred and found that the roof GL can handle 1
hour of charring and still support unfactored (service level) loads at the factored or ultimate stress
levels, again without consideration of any of the three previously mentioned options.
Furthermore, I also used the method for calculating the fire resistance of Glu-Lam Beams found in the
APA document EWS Y245B “Calculating the Fire Resistance of Glu-Lam Beams and Columns”, and
found that according to their method, the 2nd floor 6 ¾”x 31 1/2” GL beam would have 62.7 minutes
of fire resistance, and the roof 5 1/8”x27” GL beam would have 47.1 minutes of fire resistance.
Thus, for both GL types, it seems to me that the combination of 2 layers of or shaft wall or intumescent
paint GWB (on the exposed sides of the GL) should be considered as more than adequate protection as
the GL beams would have a reserve of at least 30 to 60 additional minutes of capacity during charring
even neglecting the fire protective layers) before the beams would be overstressed at service load.
If you have any questions or need additional information, please feel free to call at 206-340-2255.
Sincerely,
Greg Lee, PE, SE
Principal
ABKJ Inc.
June 15, 2018
RE: Northpoint Recovery Center
To whom it may concern,
Albi would recommend applying 40 mils WFT (28 mils DFT) of Albi Clad FP to protect the exposed glulam beams
and deck in place of using gypsum to provide a 1-hour fire resistance rating. This judgement is based on Western Fire
Center Inc. Report # 04042(a), where 40 mils WFT of Albi Clad FP is specified for a 1 hour rating on an open wood floor
joist assembly featuring 2”x10” joists and a deck of TG subfloor and CDX plywood.
Based on the Technical Note #EWS Y245B from the APA - Engineered Wood Association, the fire resistance
rating up to 1 hour can be calculated for glulam members. This method is recognized by the International Building
Code. Based on the calculations, the 6”x31” beam has a fire resistance rating of 58 minutes and the 5.5”x27” beam has
a fire resistance rating of 53 minutes. These calculations were made assuming the beams would be carrying 100% of
their maximum design load. Based on this, 40 mils WFT of Albi Clad FP applied to the exposed glulam beams will provide
the extra time necessary to achieve a 1 hour rating. Please note that Albi does not have any direct test data for Albi
Clad FP over glulam beams and this judgement is based on an established calculation method and indirect test data.
Brian Perry
Product Engineer
Albi Protective Coatings
401 Berlin Street, East Berlin, CT 06023
T 860 828 0571 Albi.com
PROVIDE 2 LAYERS OF 5/8"
TYPE X GWB AT UNDERSIDE OF
EXISTING I JOISTS
NEW 1 1/2" THICK CEMENTITIOUS
TOPPINGS OVER 5/8" PLYWOOD
7/8" RESILIENT CHANNELS
EXISTING TJI
FIRE/SMOKE SEALANT AT BOTH
SIDES COMPLYING WITH UL 2079
EXISTING GLULAM
SECTION
OPTION-1
WRAP GLULAM WITH (2)
LAYERS OF TYPE X GWB
REV TYPE:
DATE:
JOB #:
1402 Third Ave.
Suite 200
Seattle, Wa
98101
(206)652-0722
RATED CEILING AT GLULAM OPTION 1
EDMONDS RECOVERY CENTER
NORTHPOINT RECOVERY
SD2.02
Author
06/18/18
16029
PROVIDE 2 LAYERS OF 5/8"
TYPE X GWB AT UNDERSIDE OF
EXISTING I JOISTS
NEW 1 1/2" THICK CEMENTITIOUS
TOPPINGS OVER 5/8" PLYWOOD
7/8" RESILIENT CHANNELS
EXISTING TJI
FIRE/SMOKE SEALANT AT BOTH
SIDES COMPLYING WITH UL 2079
EXISTING GLULAM
SECTION
OPTION-2
WRAP GLULAM WITH 1-HOUR
RATED SHAFT WALL
REV TYPE:
DATE:
JOB #:
1402 Third Ave.
Suite 200
Seattle, Wa
98101
(206)652-0722
RATED CEILING AT GLULAM OPTION 2
EDMONDS RECOVERY CENTER
NORTHPOINT RECOVERY
SD2.03
Author
06/18/18
16029
PROVIDE 2 LAYERS OF 5/8"
TYPE X GWB AT UNDERSIDE OF
EXISTING I JOISTS
NEW 1 1/2" THICK CEMENTITIOUS
TOPPINGS OVER 5/8" PLYWOOD
7/8" RESILIENT CHANNELS
EXISTING TJI
FIRE/SMOKE SEALANT AT BOTH
SIDES COMPLYING WITH UL 2079
EXISTING GLULAM
SECTION
INTUMESCENT PAINT
OPTION-3
APPLY INTUMESCENT
PAINT TO THREE EXPOSED
SIDES OF GLULAM
REV TYPE:
DATE:
JOB #:
1402 Third Ave.
Suite 200
Seattle, Wa
98101
(206)652-0722
RATED CEILING AT GLULAM OPTION 3
EDMONDS RECOVERY CENTER
NORTHPOINT RECOVERY
SD2.04
Author
06/18/18
16029