HomeMy WebLinkAbout6.m. Receive Bids and Award Contract - Rosemount Community Center Water Intrusion RepairsAGENDA ITEM: Receive Bids and Award Contract
Rosemount Community Center Water
Intrusion Repairs
AGENDA SECTION:
Consent
Bid Amount
PREPARED BY: Dan Schultz, Parks and Recreation
Director
AGENDA NO
$93,600
ATTACHMENTS: None
APPROVED BY:
Dili
RECOMMENDED ACTION: Motion to receive bids and award the contract to Minnesota
Construction, the lowest bidder, who bid the project for $93,600.
Y
Contractor
Bid Security (yes /no)
Bid Amount
Minnesota Construction, Rosemount
Y
$93,600
Omni Construction Services, Prior Lake
Y
$98,000
Derau Construction, Burnsville
Y
$105,800
Meisin:er Construction, South St. Paul
Y
$116,300
4 ROSEMOUNT
CITY COUNCIL
City Council Regular Meeting: July 5, 2011
EXECUTIVE SUMMARY
ISSUE
The 2011 Capital Improvement Budget (CIP) includes $100,000 to make repairs to the Rosemount
Community Center to stop water from entering the building due to the faulty installation of some of the
flashing on the south side of the building. The funding comes from SKB revenues collected in 2010.
BACKGROUND
In the spring of 2010 staff received a report detailing the water intrusion problems at the Rosemount
Community Center. There is water coming into the building in a couple of locations on the southern end
of the facility near the Ice Arena. This is the same problem that the National Guard has dealt with in the
past on their part of the building. The City Council approved hiring CNH Architects to create the plans
and specifications for the project due to the positive working relationship with the City as a result of their
work on the Steeple Center. They were also the architects used by the National Guard to provide
architectural services during the repair of their water intrusion issues.
SUMMARY
The City received four bids for the project and they are listed in the bid tabulation table below.
Bid Tabulation
Staff is recommending the City Council receive the bids and award the contract to Minnesota
Construction, the lowest bidder, who bid the project for $93,600.
Rosemount Community Center
Water Intrusion
Project Information
Existing Conditions
There are two areas that water has been intruding into the interior of the Community Center. First
there is evidence of water penetrating the concrete masonry unit walls in Rooms 114 and 115. This
water has caused bubbles and deterioration of the paint on the CMU walls and will lead to more
serious damage over time. The damage is evident in the pictures below.
Picture 1 Room 115
Picture 2 Room 114
Partial Lower Floor Plan
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Leaking along this wall
The exterior of the building was also reviewed at the areas of interior leaking. First the areas above
room 114 and 115 are shown in the pictures below. This is the area around the main south entry to
the Rosemount Community Center. There are multiple visible issues contributing to the potential for
water penetration. Each of these are listed next to the pictures.
Picture 4 Scupper and planter
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Pi. ;ture 5 Sidewalk to brick wall with cracked bricks
Scuppers high on wall
Slow drainage,
trapped behind planter
No movement joint
with sealant at wall
Cracked brick veneer
Deteriorated mortar
joints
Through wall flashing
not exposed at face of
brick veneer
No movement joint
with sealant at wall
Past Studies and Repairs
CNH Architects was hired back in 2005 by the Minnesota Department of Military Affairs to review
the National Guard Armory end of the Rosemount Community Center building. This portion of the
building was experiencing water intrusion at that time. We provided a three step review of the areas
of water intrusion including the following test methods:
1. Visual inspections
2. Thermal imaging showing brick wall moisture levels
3. Physical test opening of wall system
Seeing this is the same building built by one contractor all at the same
the issues discovered on the NGA end of the building will likely by si
facility. This assumption is supported by the visual inspection done at
portion of the building we found one major moisture control issue and
The largest issue we found was with the through wall flashing at the base of the brick veneer walls.
This flashing is typical for a cavity wall system such as that used for this building. The through wall
flashing starts at the inner surface of the supporting wall, extends down 8' or more, transfers
horizontally across the air gap between backup wall and brick veneer, and then extends out to the
face of the wall. This flashing is intended to gather any moisture that gets through the brick veneer
and channel it out of the building at the base of the wall.
What we found is that the through wall flashing stops about an inch in from the exterior face of the
brick veneer. This then gathers the moisture in the cavity, but instead of directing to the exterior it
releases it into the brick bed joint and in some cases into the core openings in the brick itself. The
water then runs down inside the brick, hits the bond beam at the precast plank floor bearing and
soaks the concrete block from there down. A sketch of this condition below shows the intrusion
path.
Water Intrusion Sketch
Main water
entry point
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time, I would anticipate that
milar along the rest of the
this time. For the NGA
several contributing factors.
Water spreads at
bond beam creating
moisture from this
point down
The other contributing factors noted on the National Guard Armory portion of the building included
the following items.
Poor grade drainage away from the building allowing water to gather near the building during
stronger rainfalls.
Insufficiently sized splashblocks at scupper locations not directing water away from the
building quick enough.
Scuppers higher on wall than usual causing splashing.
Overflow scuppers near top of walls leading from drains that were flush with the roof system
instead of up to 2" above the roof as allowed by code. This resulted in water running out of
the overflows at all times, instead of only when the main roof drains were overloaded or
plugged with debri.
Poor connection of the below grade waterproofing to the top of ground allowing gathered
moisture to wick into the building below the through wall flashing.
It is my opinion that most of the items listed above also contribute to the moisture problems currently
experienced here as well.
I would also add that the sealant at the brick control expansion joints going vertically up the walls
is showing signs of exceeding its life expectancy. Several areas show cracking of sealant and in two
cases the sealant has lost its bond to the brick on one side of the joint. This joint sealant failure will
lead to excessive water penetration into the wall cavity and eventually additional penetration into the
interior.
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Recommended Remedial Actions
CNH Architects recommends the following remedial repairs to address the water intrusion currently
occurring. The measures listed were successful at resolving the moisture problems at the National
Guard Armory portion of the building.
Brick Wall and Sidewalk
Open base of wall and install new through wall flashing extending out to face of wall.
Add strip of waterproofing membrane between current membrane and the bottom of the metal
flashing.
Add stainless steel counterflashing between through wall flashing and below grade.
Replace sidewalks along building both for added joint at wall as well as to improve rainwater
flow away from building.
Provide a flexible joint filler and sealant joint at the top of any areas with sidewalks.
Rainwater Scuppers
Install large concrete splash blocks at scupper locations in lawn area.
Add 2" pipe extension at overflow roof drains.
Knee Wall at Translucent Panels
Remove existing caulking.
Install new caulking.
Repaint caulking and trim.
Control Expansion Joint Caulking
Remove existing caulking and rod at existing joints.
Install new caulking and rod at existing joints.
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Remove and replace
sidewalk
Replace through wall
flashing, 3 walls (102 If)
Conclusion
The water intrusion being experienced in the lower levels of the building appear to be from the same
causes previously discovered and repaired on the National Guard end of the building. The remainder
of the water intrusion is from sealant joints that have reached their life expectancy. The water
intrusion will continue at current or increased levels if not addressed and will lead to deterioration of
concrete masonry unit walls, mortar joints, and interior finishes. The high moisture levels will also
provide increased risk of mold growth.
The repairs indicated should resolve the moisture issues as they have done in the previous work.
On behalf of CNH Architects, thank you for the opportunity to provide this review. I look forward to
continuing to assist the City of Rosemount.
Best Regards,
Quinn S. Hutson, ALA, LEED AP
Reg. No.: 21234
Principal
CNH Architects, Inc.
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