Permit:                        C16-1596

                        X16-2092
Change Order/Deferred Submittal for Curtain Wall

Date:               3-21-2017

Reviewed by: Ron Wilde                                                                 

Phone:             343-8371

Fax:                 343-8200

Email:                         wilderg@muni.org

Project:           Dimond
Center South Entry Stairs

Change
Order/Deferred Submittal for Curtain Wall

1.  PERMIT STATUS

1-17-2016 – Permit reviewed. Comments issued.

3-21-2017 – Response reviewed.  Comments issued.

5-2-2017 – Response reviewed.  Comments issued.

2.  Advisory Comment (no response required):  This review is based on the requirements of
the 2012 Anchorage Administrative Code (AMC 23.10), 2012 International Building
Code (IBC), and all adopted references thereto as amended by MOA. The following
comments must be addressed before a permit can be issued. The approval of plans
and specifications does not permit the violation of the codes, or any federal,
state or local regulations.

Please submit a
written explanation for how each comment has been addressed.

3.  COMMENT REMAINS 3-21-2017

LOAD PATH – STEEL PORTION OF MULLION TO SUPPORTS

The steel portion of the mullion takes approximately 70
percent of the composite aluminum/steel mullion.  Please provide design and details to show how
the reaction in the steel and aluminum portions is transferred to the
structure. 

The submitted details do not appear to follow the
standard Kawneer drawings for attachment to the structure by through bolts that
go through both the steel and the aluminum. 
Please coordinate with Kawneer.

3-21-2017 As you stated, the steel and aluminum portions
share load according to their relative rigidity.  This comment asks you to show the load
path for the reaction of the steel portion. 
The reaction load at the ends of the steel portion must be transferred
to the structure through a code-compliant load path.  Please provide the calculations and details
for this load path.

5-2-2017

I talked with John Kramer (479-756-4431) from Kawneer in
order to understand their intended load path for linking the aluminum mullion
with the steel core.

The steel and aluminum are intimately connected by
screws.  These screws can be seen in
Details 1 and 2.  The screw goes through
the aluminum and the steel as shown.  The
load from the steel does not transfer into the aluminum through bearing.

Please show the type, size, and location of these screws on
the drawings.  Provide calculations for
the screws showing they are adequate to transfer the reaction in the steel core
to the aluminum mullion.

You are correct that the load then transfers to the structure
from the aluminum mullion through the T and F clips.

4.  Comment resolved 5-2-2017

COMMENT REMAINS 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF

This detail transfers load only out of an aluminum cap
plate of unknown thickness on top of the aluminum mullion.  No attachment of the aluminum cap plate to
the aluminum mullion is shown.  Please
show how the force is transferred from both the aluminum (162003) and steel
mullions (162301/302).

3-18-2017  The
F-clips have fasteners that are offset from the centerline of the mullion.  Please provide calculations to show the
fasteners are adequate to resist the eccentricity.

5.  Comment resolved 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF – STEEL BENT PLATE

Unless this plate is intended to be continuous, please
show its width on the drawing.  The
calculations on page 315 show the width to be almost 13 inches.

6.  Comment resolved 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF – STEEL BENT PLATE WELDING.

Unless this plate is intended to be continuous, please
show the welding for each plate rather than a skip weld.  Please note that if this plate is intended to
be continuous, placing the weld will be difficult and may impact the capacity
of the shear connection of the metal deck. 
Please clarify any needed precautions for cutting the deck.

7.  Comment resolved 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF – MEMBRANE BETWEEN ALUMINUM AND STEEL

Please identify the kind and thickness of membrane.

8.  Comment resolved 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF

STAINLESS STEEL
CONNECTORS – AUSTENITIC STAINLESS STEEL

Please show on the drawings that the stainless steel connectors
are to be “austenitic, or else that they comply with the requirements of 2005
Aluminum Design Manual (ADM), 5.4.1 or the 2010 ADM equivalent.

9.  Comment resolved 3-21-2017

DETAIL 1 (SKS9) –
CURTAIN WALL ATTACHMENT AT ROOF – BOLTS

It is not clear how bolts can be installed.  Please clarify or delete this option.

10.  Comment resolved 5-2-2017

DETAIL 3 (SKS3) –
CURTAIN WALL SUPPORT FRAME – CONNECTION TO SUPPORT ANGLE

The sketch indicates that the manufacturer will supply
this detail.  The design and detail needs
to be supplied and reviewed before a permit can be issued.  The detail needs to show how the force is
transferred from both the aluminum (162003) and steel mullions (162301/302).

3-18-2016  The
detail needs to show how the reaction force in the steel is transferred to the
structure.  There must be a
code-compliant load path.

11.  Comment resolved 5-2-2017

SUBMITTAL DRAWINGS

Please submit 2 full-size final sets of drawings that
show how the curtain wall is to be constructed. 
Please include both layout drawings with member identification and
connections, along with drawings that show how the curtain wall attaches to the
structure.  The drawings need to be
complete such that a contractor can order and install the curtain wall.  If a member is necessary, identify it and
give design properties, dimensions, and material.  If connections are necessary, identify the
fastener and its material, and show how many and where the fasteners are
located.

Please note that the Kawneer drawing that has already
been submitted does not identify the mullions or their steel core and does not
show how the core is connected to the aluminum. 
This is not sufficient.

3-21-2017 Please
provide 2 full-size final drawings stamped by an Alaskan P.E.  All of the layout and detail information can
be on a single, stamped, full-size drawing.