HomeMy WebLinkAboutRoof ReportAPPENDIX D
ASLC ROOF REPORT
BEZEK DURST SEISER ARCHITECTS
ASLC Heat Recovery Project
AEA Renewable Energy Fund Round VII Application
Alaska Seal.ife Center
Roof Report
Seward, Alaska
February 13, 2013
Prepared by:
Bezek Durst Sesser Architects •
Roof Technology Group
3330 C Street ... .
Anchorage, AK 99503 •
907-562-6076 B S
Alaska Seal_ife Center Roof
CONTENTS
Roof Narrative
Photos
O Roof Construction Cost Estimate
Y Acronyms
Roof Plan and Details
ALASKA SEALIFE CENTER
ROOF REPORT
Seward, Alaska
February 13, 2013
Report Summary
Due to roof leaks occurring since the building was initially constructed, our recommendation is to
replace the roof at the Alaska SeaLife Center per Option 1. Option 2 is also a more costly good choice
if it is determined that the odors of asphalt roofing cannot be tolerated or avoided by resident wildlife.
Included within both of the proposed roof systems are: The membrane, sloped insulation that
improves roof drainage and provides R40 value, vapor retarder, new roof drains, and 30 year "detail"
design.
This is a complex building in both shape and use, the sensitive wildlife it houses, and serves the
public. We suggest that this opportunity to correct roof deficiencies should be done at a high level of
quality to avoid leaks and premature replacement.
Option 1- MCBUR: A very durable 5-ply built -up -asphalt roof membrane (BUR), lasting an
average of 30 years. Approximate 2013 cost: $2,300,000
Option 2 — LAM. A very durable liquid applied roof membrane (LAM), lasting an average of 30
plus years. Approximate 2013 cost: $3,100, 000
General Information
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The roof of the Alaska Sea Life Center (ASLC) was investigated October 29 and November 12, 2012.
John Stadum and Bruce Owens of Bezek Durst Seiser's (BDS) Roof Technology Group performed
the roof system investigation for this facility. Darryl Shaefermeyer of the ASLC provided a tour of the
roofs and facility interiors along with the many complex systems required to support the wildlife. Darryl
also provided a history of the roof issues since it was built in 1996. Snow was present on some areas
of the roof surface.
The roof and building were thoroughly photographed and documented for this report and for in -office
design reference. The roof was measured to verify the original drawings and to establish quantities for
costs. A key roof area was cut open, dismantled and documented to determine existing conditions; it
was patched professionally. Roof slope and drainage were established. The building interior was
viewed to verify conditions, finishes, and leak locations. Original construction drawings were reviewed-
Existing Conditions
The majority of the roof sections at the ASLC have a single -ply EPDM rubber membrane over rigid
insulation. The roof system is constructed as follows from the top down:
45 mil EPDM membrane
1/2" wood fiberboard
2 layers of 4" EPS insulation (R33)
• 5/8" GWB
Polyethylene vapor retarder
1 '/2" steel roof decking
The roof insulation and sponge -like wood fiberboard are wet where the membrane has leaked. The
roof decks vary in slope from 0:12 to 1/2:12. The building is complex with numerous roof levels,
individual roof sections, and configurations. See the attached drawings for a roof plan and a detail
showing existing roof components.
Issues, Topics, and Solutions
Following is a list of issues and topics with applicable solutions:
1. The EPDM rubber membrane leaks, and is aged at 16 years old. The roof has leaked often
times since the building was constructed due to: miscellaneous punctures in the roof
membrane; punctures from screws backing out of the steel deck; failed membrane seams;
weak roof and wall flashing details, and from high winds driving rain into the roof system and
walls.
Solution: Replace the membrane and improve the details.
2. The EPDM rubber membrane is not durable enough to survive the severe weather conditions
in Seward. EPDM is a thin rubber product that is relatively easy to puncture, much like a
bicycle tire inner tube. Roofs 7 and 10 have locations where ice and snow from the aviary
canopy slides and fah onto the roof, has punctured the thin membrane and caused leaks into
the interior. In addition, rooftop snow removal has to occur during winter and carries the risk of
further damaging the fragile rubber membrane.
Solution: Install a more durable roof membrane surface to resist damage.
3. The roof slope is too low for proper drainage. The existing roof slope on the building varies
from 0:12 to 1/2:12. Lack of sufficient slope to drain reduces overall roof life and increases the
severity of roof leaks. A minimum slope of 1/4:12 is required by code, most roofing
manufacturers and is a design industry standard.
Solution: Increase the roof slope by adding tapered insulation under the roof membrane to
improve runoff to the roof drains.
4. The polyethylene vapor retarder is weak. The poly vapor retarder is porous due to thousands
of screw penetrations through it from the screw attached membrane. Continuous roof vapor
retarders are critical in Alaska's climate to prevent interior water vapor from migrating into the
roof system. Moisture from a leaky vapor retarder becomes trapped in the roof system and can
2
condense, freezing in winter and melting at breakup. If enough moisture collects, a roof
condensation melt leak occurs.
Outside moisture penetrating the membrane can collect on the vapor retarder and flow to
locations long distant from the entry point. This particular problem has been experienced at the
ASLC.
Solution: Install a water and vapor proof asphalt vapor retarder (without screw penetrations)
that ensures humidity inside the building will not enter the roof system. In addition, a quality
vapor retarder provides a reliable secondary waterproof layer that will protect the building
during reroof construction and serve as a redundant membrane for the life of the roof.
5. Screws are backing out of the roof system. The ASLC roof system is mechanically attached,
with the membrane attached to the building with rows of screws about seven feet apart. The
membrane between the attachment points is free to move and billow in the high winds that
frequently occur in Seward. Screws have backed out and penetrated the EPDM membrane,
causing leaks. The membrane movement also pumps air and leak moisture throughout the
roof system, causing elusive leaks where water has run along the vapor retarder and dripped
into the building at a separate location away from the entry point. Roof leaks are costly,
unnecessary irritants, and require time consuming repairs for the ASLC.
Solution: Install an adhered (glued down) roof system that performs well in Seward weather.
6. Ice and snow avalanches have previously overloaded the roof trusses at two locations
adjacent the aviary. The aviary is protected by a space frame canopy roof with a slick tarp roof
covering. In winter, snow and ice slide from the tarp roof onto Roofs 7 and 10. The pile of ice
and snow from the avalanche is very heavy and overloaded Roof. 10 to the point of damaging
the interior ceilings when the trusses deflected from excessive snow load. Ice falling from the
tarp roof has punctured the roof membrane on Roofs 7 and 10 several times allowing water to
leak into the roof and building. (see attached roof plan for locations)
Solution: Upgrade the structural roof members during a roof replacement project.
7. The Alaska SeaLife Center is an extremely complex facility, unlike any other building in
Alaska. Thousands of sc oo c i dreri nuns s, an residents residents 'fourlhY fa-Cllity each year. Tire
facility functions as a zoo, a museum, a research and educational facility for a variety of
animals, birds, fish, invertebrates and wildlife. To care for these animals and birds, the ASLC
hosts a variety of veterinarians, scientists, researchers and staff working on numerous
programs that also include endangered marine mammals, birds, fish, and crustaceans.
The ASLC has veterinary hospital and surgery facilities, in house. Throughout the building are
very complex freshwater, saltwater, sewage treatment and life support systems for the
residents and high volumes of water coming in and going out of the building. It will be vital for
the facility that these services remain operational during reroof construction. This will add
additional cost and construction complexities.
Solution: Design the roof replacement project around the complex facility requirements.
8. Animals and Birds sensitivities. The resident wildlife will add complexities beyond normal to a
roof replacement project at the ASLC. The animal's and bird's tolerance of disruption and
odors will have to be carefully considered and coordinated by the ASLC so that the residents
will not be disturbed. There are animals at the ASLC that are endangered and are protected by
federal law.
3
Solution: Study this issue with the ASLC experts. Consider creative solutions. Design a reroof
project to ensure that resident animals and birds are not disturbed.
9. The exterior walls at the ASLC are not weather -tight. The wall detail is a complex ventilated
parapet and wall system, with 1 '/z" perforated steel decking behind the high-grade zinc metal
exterior wall siding. Evidence of water intrusion into the roof parapet wall was discovered at a
random test cut location so it follows there are other parapet and wall leaks. The wall design
complicates the new roof installation due to the effort required to construct the new base
flashing details. (see attached roof plan and details).
Solution: Design the reroof and wall details so that they are watertight in rainy high -wind
conditions.
"Membrane" Discussion (Single -ply, MCBUR, LAM)
There are several types of roof membranes in use in Alaska and all vary in quality and
appropriateness for a specific building and environment. If designed and installed correctly, most
membranes will provide weather protection for some period of time. However, there can be many
differences and variables in roof systems that affect a roof's overall performance. The quality of
design, the contractor's workmanship and the installation environment are some of the primary factors
that will influence roof life.
Key items to consider in selecting any long-term roof membrane are: reliability to resist leaking,
durability to resist the onslaught of the elements, how it ages, roof traffic, maintenance requirements,
the initial cost, and the long term cost, averaged per year.
Single ply Membranes
A single -ply roof membrane is field fabricated from "single" layer sheets of thin, sheet materials,
usually strengthened with a reinforcing fabric. The up to 20 feet wide roll sheets are glued or welded
together at the edge lapped seams to form a continuous waterproofing layer. In Alaska, typically three
different types of-single-pTy membranes are u i izeri-The most -common mernbrane#s ruWX9-EPOi ,-
others are plastic -based PVC and TPO. TPO is a young, somewhat untested combination of rubber
and plastic.
The primary disadvantage of single -ply membranes is that if a mistake is made while installing the
single layer of waterproofing, a leak occurs. In the case of multi -ply membranes, such as MCBUR or
monolithic membranes like LAMs, a similar mistake does not result in a leak as multiple layers of
waterproofing are applied and an error is generally forgiven. Another drawback is that single -ply
membranes (especially EPDM), can be fairly easily punctured or damaged by sharp rocks or screws
in shoe soles, by birds, tools, snow removal and so on. Finally, single -ply membrane seams have a
history of failing before the rest of the roof.
In general, well done single -ply EPDM and PVC membranes will last an average of 20 years on a
building in Alaska, depending on installation quality, design quality, the environment, the building
configuration, and other factors. Roofs designed and constructed properly give the owner a much
better chance of success.
MCBUR Membranes (multi -ply)
In general, a well installed, low -sloped, built-up asphalt membrane with mineral cap surfacing
(MCBUR) will perform well in Alaska and last an average of 30 years. When properly designed and
constructed, these durable membranes will require minimal maintenance.
For low -sloped or "flat" roofs, we often recommend MCBUR due to its long life, its error -forgiving
multiple layers, and its durable and ultraviolet protective mineral surface. Typically, MCBUR roofs will
not only last longer, they have less frequent problems than single -ply roof membranes. During roof
application, the multiple asphalt ply sheets are adhered to the roof surface and to each other with a
special, low odor, hot asphalt. They are fabricated into a homogeneous waterproof roof membrane to
protect the building. This "custom fit" style of roofing works well and has proven itself for generations.
Single plies began in Alaska around 40 years ago.
Following is a description of a typical reroof process utilizing a MCBUR membrane. See also the
attached "proposed detail' drawing:
Adhered Roof System (excluding the membrane)
1. The old roof system is removed from the roof deck.
2. A layer of GWB is screw attached to the steel deck.
3. A 2-ply asphalt BUR vapor retarder is applied to the GWB. This membrane prevents leaks
during construction and provides a secondary waterproofing layer in the roof to resist future
leaks. This is the best vapor retarder for Alaska and it is inexpensive.
4. One or more layers of flat insulation are adhered to the VR.
5. A layer of tapered insulation (for 1/4:12 finished slope) is adhered to the previous insulation
layer.
6. A protective substrate of either wood fiberboard, GWB or OSB is adhered to the top layer of
insulation.
MCBUR Membrane components (5 plies)
7. A heavy roofing base ply, a 3-foot wide rolled sheet, is adhered to the substrate. This heavy
sheet serves as a founda ion to the waterproofing poilion of the membrane.
8. The waterproofing portion of the membrane is composed of 3-olies of BUR.
9. The mineral cap sheet is thick, durable, and ultraviolet protective. This layer is the surface
protection.
MCBUR generally costs slightly more to install than single -ply roof systems due to increased labor,
setup, and materials cost; but an MCBUR membrane will, on average, provide 50% longer service life
with less potential for problems than single -ply roof membranes.
LAM Membranes (Monolithic)
There are many different types of liquid applied membranes (LAM), and most LAM roofs are applied
in a similar fashion to MCBUR roofs, although with fewer layers. The vapor retarders and insulation
layers can be installed similar to built-up roofs (see the Adhered Roof System description below). The
typical LAM membrane is typically a mix of one or more polyester or urethane resins that react with
additives to cure into an elastomeric waterproofing material. The LAM roof membrane is installed in a
process of saturating one or more layers of heavy polyester reinforcing felt with the resin component.
5
and finally covering the assembly with topcoats. The finish topcoat may be a color coat or it can have
a layer of mineral aggregate embedded in it for traction, to provide UV protection, and extend the LAM
membrane life.
LAM roof systems generally cost more than MCBUR roofs systems due to increased materials cost
and the extra labor to install. LAM roof installation does produce odor, but not as much odor as does
asphalt roof application. When correctly designed and installed, a LAM roof system such as Kemper
Manufacturing's "BR" Membrane is one of the most durable roof systems that can be installed, custom
made to fit the building, with a proven track record of lasting 30 to 35 years.
Adhered versus Mechanically Attached Roof Systems
Roof systems, as differentiated from the roof membrane, can be installed several ways. The three
primary methods to secure a roof membrane to a building are by screw attachment, adhesive, or by
ballasting. The roof system at the ASLC is mechanically attached with screws; the roof membrane is
intermittently secured to the roof deck and is free to billow and move in high winds, stressing the
EPDM material pulling at the securement screws.
Adhered roof system components are secured by adhesives and unable to move in winds. Ballasted
systems are also not free to move in the wind. As a result, these roofs do not experience wind driven
wear and tear as do mechanically attached roof systems. A drawback to ballasted roofs is that
experience in Alaska has shown us that some ballasted roof systems may not perform well during
high wind events, such as would be experienced in Seward. Ballasted systems are costly to repair in
winter, especially as they age, plus the membrane cannot be seen so cannot be inspected for flaws or
leaks.
To correct the shortcomings of mechanically attached systems, we recommend that the new roof
system for the Alaska SeaLife Center be installed as an adhered roof system with all roof components
securely glued to the building. This installation method will resist high winds, avoid screw back -out,
and ensure that the roof system will last the full length of its potential life.
Warranties
There are numerous variations on roof warranties, with two basic types of warranties specified:
1. A "Manufacturer warranty" for the roof system typically ranges from 10 to 20 years. The
contractor is typically responsible for the first two years of performance and the manufacturer
takes over after that.
2. A "Contractor Workmanship warranty" is typically for 2 years. The two-year logic is that the
roof system is assured of going through at least one winter season.
Discussion of roof system and roof membrane warranties can be extended and involved as touched
on above. There are differences between manufacturer's membrane warranties and also differences
between single -ply (EPDM) and multi -ply (MCBUR) membrane warranties. Warranties can be
advantageous to the building owner depending on several things or they can be more advantageous
to the manufacturer. Keep in mind that the manufacturer writes their warrantees.
We recommend caution when dealing with manufacturer warranties since the quality of the roof
system products, the design, and the installation should be the primary considerations In our opinion.
roof systems should not be selected based heavily upon the availability of a long-term warranty. With
6
a top quality roof system, a reputable manufacturer, good quality design, skilled installation,
experienced third -parry construction observation, and experienced maintenance inspection; a long-
term warranty then has much more validity.
Recommendations and Costs
MCBUR - OPTION 1: Our recommendation is to replace the existing roof with a new fully adhered, 5-
ply built -up -asphalt roof membrane with a very durable mineral cap surface (MCBUR), which will last
an average of 30 years. Included with this new roof system is: the roof membrane, flat and sloped
insulation to improve roof drainage, R40 insulation, replaced roof drains, and 30 year "detail" design.
The cost to install an MCBUR Roof System on the Alaska SeaLife Center in 2013 would be
approximately: $2,300,000.
LAM - OPTION 2: H the asphalt odor is determined to be incompatible with the resident wildlife, we
suggest installing a Liquid Applied Membrane (LAM) such as Kemper's BR System with a mineral
aggregate surface. All roof components such as the vapor retarder and insulation of this option would
be similar to the MCBUR option above, except the underlying roof products would be adhered in a
low -odor adhesive in lieu of hot asphalt. The cost to install a LAM Roof System on the Alaska SeaLife
Center would be approximately: $3,100,000.
(Note the estimating methodology utilized to provide Option 2 costs was to determine the difference
between the MCBUR membrane and the LAM. We have the MCBUR at about $6/sf. After calls with
several manufacturer resources we determined the difference in membrane cost to be approximately
$21/sf, times 38, 000 sf totals about $800, 000.)
End -
1M3ds7Pro;ects1000000's�012007 A;aska SeaLife Cefile Roof12 Reportlreporf ,termslRoof Fepo t docx
Alaska SeaLife Center Roof
II,!IIl�
1 of 7
1. Front entrance to the Alaska
SeaLife Center facing SW.
p- Note: Referencing the roof plan
"" while reviewing these photos
will be helpful.
. Partial view of the West
xterior walls of the ASLC.
lote the arched space frame
anopy above the aviary.
3. North and partial west side
view of the ASLC. View is
facing SE.
Alaska Seal-ife Center Roof
2 of 7
4. View of the west side of the
facility, facing NE.
5. Roof 10, facing SE.
6. Partial view of Roof 7 facing
east. The space frame canopy
with the slick tarp cover over
the aviary is at left. An extra
layer of rubber roofing is
installed on the original roof in
an attempt to prevent
punctures and leaks from ice
and snow sliding from the
canopy (outlined in red)
Alaska SeaLife Center Roof
3of7
7. Roof 10, facing SW. The
space frame canopy with the
slick tarp cover over the aviary
is at left. Heavy loads of ice
and snow slide from this
canopy onto Roof 10, at right.
Roof leaks and deck deflection
due to roof overloads have
occurred below the canopy,
and the roof insulation here is
wet and outlined in red.
8. Partial view of Roof 8 along
its west parapet, facing south.
The walls of penthouse Roof 9
are at left. Note the metal
siding low to the roof surface.
(in circle) The lower portion of
the siding will need to be
removed to construct a proper
roof to wall detail.
9. View of Roof 5 at center,
facing west. The north wall of
penthouse Roof 4 is at left.
Roof 6 is at right. Note the
metal siding low to the roof
surface. (in circle) The lower
portion of the siding will need to
be removed to construct a
proper roof to wall detail.
Alaska SeaLife Center Roof
L
F ..
Awl-
4of7
10. Roof 3 at left; the north and
east walls of the Penthouse
(Roof 4) are at center beyond;
a partial view of Roof 5 is at
right. View is facing SW.
11. View of Roof 6 facing west.
12. Roof 13 from Roof 7, facing
SE Roof 15 is at arrow.
Alaska SeaLife Center Roof
Roof 1
t"
5of7
13. View of Roofs 1 and 2 at
the south end, from Roof 3;
facing SW. Roof 2 has a
concrete paver walking
surface.
14. Roof 8: Patches in the
EPDM membrane where
backing out screws protruded
up through the membrane and
caused leaks. (at the arrows)
The strip between the red lines
is a repair over a leaky roof
seam. Note the low clearance
between the roof and wall
siding. (in circle) This base
flashing detail will need to be
raised for adequate clearance
between roof and wall siding.
15. View of Roof 8 and roof
penetration congestion
consisting of stacks, fans, guy
wires, and exhaust fans. The
tall boiler stack with the support
framing is wobbly and in need
of upgrading These details will
need to be upgraded during a
reroof with consideration for the
frequent snow, rain and high
winds in Seward.
Alaska SeaLife Center Roof
16.
r _
4A,
6 of 7
16. Roof 10: A typical view of
the many wall mounted lights,
conduits, cables, and related
roof penetrations to be
upgraded when reroofing
occurs.
17. Roof 10, far east comer:
View of the roof to wall
membrane with diagonal
wrinkles showing lateral strain
(at red lines) caused by
differential movement between
the roof and walls. This
condition should be
investigated and corrected
during the reroof design, as the
movement will eventually
damage the waterproof
membrane.
18. Roof 10: Removing piles of
waterlogged snow below the
rounded aviary canopy. The
snow blocks water flow to roof
drains. Falling ice from the
canopy damages the roof
membrane, and leaks have
caused damage to the interior
ceilings. (photo courtesy of
ASLC)
Alaska SeaLife Center Roof
" L X"'- 01
7of7
19. Top of the parapet with the
metal cap removed at the test
cut location. The arrows show
the airflow path that allows
wind driven moisture to enter
the top of the exterior walls.
The GWB on top of the parapet
showed evidence of getting wet
at the area in the circle. No
insulation was in the wall above
roof level, a situation that
promotes condensation or frost
to form inside the wall in cold
temperatures. Improvement
needed.
20. Roof leaks above the front
lobby escalator. The escalator
had to be shutdown. Note the
water damage to the ceilings at
the arrows. (photo courtesy of
ASLC)
21. Buckets catching water on
the second floor from roof
leaks. Note the water collection
buckets and the damaged
ceiling finishes at arrows.
(photo courtesy of ASLC)
Alaska Seal-ife Center Reroof (MCBUR Option)
Roof Construction Cost Estimate (report level 2/13/2013
Item
Quantit
Unit
$/Unit
Total
General
1
Mobilization
1
ea
10,000.00
$ 10,000
2
Insurance, bond, permit, etc. (aeprox 4%
1
ea
76,000.00
$ 76,000
3
4
Demolition
5
Remove EPDM membrane, mechanically attached
37,904
sf
0.50
$ 18,952
6
Remove 1/2" wood fiberboard, loose
37,904
sf
0.15
$ 5,686
7
Remove 10" ave EPS insulation, 3 layers, loose
37,904
sf
0.60
$ 22,742
8
Remove 5/8" GWB
37,904
sf.
0.30
$ 11,371
9
Remove poly vapor retarder
37,904
sfj
0.15
$ 5,686
10
Clean steel deck
37,904
sfi
0.15
$ 5,686
11
Remove 1/2" GWB from parapet
1,980
Ifl
3.00
$ 5,940
12
Remove seismic joint parapets
235
If1
30.00
$ 7,050
13
Remove parapet cap system
1,980
If1
5.00
$ 9,900
14
Detach/cut bottom of metal panels at sidewalls
585
Ifi
75.00
$ 43,875
15
Demo birdnettin anchor detail, temporarily secure
240
If
55.00
$ 13,200
16
Dumpfee, 5.6 psD
106
tonj
55.00
$ 5,830
17
Dump hauling
106
toni
65.00
$ 6,890
18
19
New work
20
Perimeter parapets, add nailers, VR seal, insulation
1,980
If1
25.00
$ 49,500
21
Seismic joint parapets, add VR seal and insulation
235
If1
50.00
$ 11,750
22
5/8" GWB, base sheet, screw attached
37,904
sfj
1.85
$ 70,122
23
2-ply BUR vapor retarder
37,904
sfj
1.25
$ 47,380
24
EPS insul., two 4" layers, R33, adhered w/ adhesive
37,904
sfj
6.00
$ 227,424
25
Tapered EPS insul., ave 3", R12, adhered w/ adhesivf
37,904
sfj
2.30
$ 87,179
26
Crickets, in adhesive
26
eal
500.00
$ 13,000
27
1/2" wood fiberboard, in adhesive
37,SR
1.90
$ ?2,-0 8
28
5-ply MCBUR.
37,904
6.00
$ 227,424
29
Sidewall modification, zinc siding, vent detail
585
lif
30.00
$ 17,550
30
Seismic joint detail
235
20.00
$ 4,700
31
Perimeter parapet metal copings & cleats, vent detail
1,980
30.00
$ 59,400
32
Sidewall/ ara et detail at concrete/shotcrete walls
512
Ifi
45.00
$ 23,040
33
Bird netting anchor detail with metal flashing
240
If
30.00
$ 7,200
34
Small penetration details and extensions
130
ea
400.00
$ 52,000
35
Small curbs
9
ea
500.00
$ 4,500
36
Lar a curbs, stack details
7
ea
500.00
$ 3,500
37
Roof drains; main and overflow
34
ea
3,000.00
$ 102,000
38
Electrical; lighting, replace & relocate conduits
1
ea
75,000.00
$ 75,000
39
Roof access ladders for roofs 4, 6, 9
4
ea
2,500.00
$ 10,000
40
Small curbs
9
ea
500.00
$ 4,500
41
Room & board, 12 weeks, 9 people
140
days,
237.00
$ 33,180
42
Travel, roundtri s
251
tripstripsi
540.00
$ 13,500
43
Crane, loading, 12 weeks
121
eal
4,000.00
$ 48,000
Page 1 ASLC Reroof cost est 35%.xlsx
44
Temp. covers & tenting roof
1
ea
150,000.00
$ 150,000
45
Structural fix below canopy with finishes
1
ea
140,000.00
$ 140,000
46
Electrical upgrades
1
ea
25,000.00
$ 25,000
47
Premium for construction with resident animals, birds
1
ea
50,000.00
$ 50,000
48
Premium for construction while open to public
1
ea
20,000.00
$ 20,000
Subtotal $ 1,897,675
Contingency 20% $ 379,535
Total $ 2,277,210
Notes:
A. 2013 summer construction assumed, bid prior to 5-1-13.
B. Labor and materials included
C. Contingency is for weather, estimating generalizations, unforeseen circumstances
D. Hourly rates assumed at $90/hr, profit & overhead included
E. This is a moderate detail estimate which could err 15% +/- depending on bidding climate
F. Minimum 3 competitive roofing contractor bids assumed
G. Design, construction, permits, owner fees not included
H. Unknown decay & corrosion not included
Page 2 ASLC Reroof cost est 35%.xisx
ACRONYMS
BLDG..................................................................................................................... Building
BUR ..................................................
Built -Up -Roof (Hot asphalt multi -layered membrane)
EPDM.................Ethylene
Propylene Diene Terpolymer (Rubber single -layer membrane)
CAP ....................................................
Cap sheet (top layer of an asphalt roof membrane)
EL......................................................................................................................... Elevation
EOF...........................................................................Emergency
Overflow Scupper
EPS..................................................................Expanded Polystyrene (Insulation)
GALV.................................................................................................................
Galvanized
GWB......................................................................................................Gypsum
Wallboard
LAM............................................................................................
Liquid Applied Membrane
MIL..............................................................
One Thousandth of an Inch (unit of measure)
MCBUR........................................................
............. Mineral -Cap -Surfaced Built -Up -Roof
OC.......................................................................................................................
On Center
ORD....................................................................................................Overflow
Roof Drain
OSB............................................................... Oriented Strand Board (sheathing material)
POLY....................................................................................... Polyethylene vapor retarder
POLYISO (iso)
...................................................................... Polyisocyanurate (Insulation)
PVC ..................................................... Polyvinyl Chloride (Plastic single -layer membrane)
PT........................................................................ Preservative Pressure Treated (Lumber)
R................... ..............................
Resistance -Value (Refers to thermal insulation capacity)
RD...................................................................................................................
Roof Drain
SAM...........................................................................................
Self Adhering Membrane
SF....................................................................................................................
Square Feet
TPO..........................................
Thermoplastic Polyolefin (Plastic single -layer membrane)
VR............................................................................................................Vapor
Retarder
VTR.................................................................................................
Vent -through -the -roof
WF.......................................................................................Wood
Fiberboard (Insulation)