AGENCY REQUEST FOR
STATE BUILDING COMMISSION ACTION
November, 2008
DSF #08J3P
AGENCY:
Department of Administration
LOCATION:
State Capitol
Madison, Wisconsin
REQUEST:
Request authority to construct a Dome Moisture Repair Phase 1 Project at the State Capitol for
$1,952,800 GFSB – Facility Maintenance & Repair.
PROJECT DESCRIPTION:
The project represents Phase I of a two phase project to correct the moisture/humidity and
corrosion problems occurring in the State Capitol Dome. This project includes:
 Installation of a closed dehumidification system in the interstitial space.
 Inspection of the exterior dome including the removal of sealants, and the installation of
caulking and tuck-pointing at the base of the exterior dome.
 After the interstitial truss space is dehumidified, remove paint on the lower 15 feet of the
dome.
 Provision of a field inspection of the compression ring at the dome top to review/identify any
corrosion from leakage from the roof at the lantern.
JUSTIFICATION FOR THE REQUEST:
The Wisconsin State Capitol was built over an 11year period – 1906 through 1917. The architect
for the building, George Post & Sons, designed it the Beaux Arts style. The surface of the
building is bethel white granite from Vermont.
In the past, the compression ring of the Capitol Dome had suffered severe rust problems caused
by lantern window condensation and leaks, and was repaired in the 1982. However in June 2003,
evidence of moisture, excessive pealing paint was first observed on the inner rotunda dome. A
2004 inspection of the interstitial space between the inner and outer domes revealed rust on the
steel structure. It is highly probable that the moisture causing rust formation could have a
deleterious affect upon the steel truss connections and tension ring. There are 24 steel trusses
supporting the State Capitol dome. Structural failure of any one truss connection or the tension
ring could have catastrophic results.
In early 2008, the first portion of the Dome Moisture Study was completed. It provided a visual
inspection of the dome and installed instrumentation to monitor the exterior dome, interstitial
dome space and internal dome for movement, temperature, moisture and humidity. Four
temperature/moisture probes and movement sensors were installed around the dome to record and
study air quality conditions (i.e. temperature, humidity, and air pressure) in the interstitial space
between the inner and outer domes and the moisture content of the masonry of the dome
structure. A weather station was installed at the top of the dome to help analyze the results of the
monitoring sensors. As a result of the information collected, the consultants recommended that a
structural evaluation of truss stone connections and truss pins at the base of the dome be done to
provide an evaluation of deterioration and corrosion.
In September 2008, the 2nd component of the Dome Moisture Study was completed. Its findings
indicate that several factors are contributing to the moisture/humidity and corrosion problems
occurring in the interstitial space of the Capitol Dome. These are:
 Un-vented interstitial space to the outside – except for four roof drains. The high humidity in
this space is a major contributing factor to the corrosion of trusses and intermediate tees
between trusses.
 Water has leaked into the interstitial truss space from the base of the lantern, lantern windows
and façade on the roof. – resulting in corrosion to the compression ring.
 Water leaks have occurred through the stone mortar joints.
 The Capitol is now air conditioned so the air on the inside of the dome is dryer and cooler
than the exterior air during the summer months.
 In the past, exterior joint repairs to the dome have been made using sealant instead of mortar.
This has resulted in a tighter but less breathable structure. In addition, at the base of the
dome, several stone joints that were originally open, have been caulked – further reducing the
ability of the dome base to breathe.
 The interior of the dome has been painted. This results in a non-breathable membrane on the
inside face of the terra cotta so that moisture on the terra cotta is able to dry out only on the
inside of the interstitial space.
Installation of a dehumidification system in the dome’s interstitial space; the removal of sealants
and installation of caulking and tuck-pointing, the use of latex based paint instead of oil based
paint on dome plaster combined with on-going monitoring of dome instrumentation, should result
decrease water moisture and resulting problems in the Capitol Dome.
This project was included in the SCERB approved 10 Year Plan of Maintenance and
Improvement Projects for the State Capitol and was also identified in the DOA Six Year Plan
(2007-2013) All Agency Projects for construction in the 2007-2009.
BUDGET & SCHEDULE:
Budget Line
Construction
* A/E Design & Inspection –
18%
DSF Management Fees – 4%
Contingency – 10%
% for Art
Total Budget
$1,450,000
$ 294,000
Total Project Cost
$1,952,800
$ 63,800
$ 145,000
$
0
* A/E fees include field inspections of dome, compression ring and roofing at base of lantern and
construction documents for interstitial truss space, exterior dome, and interior dome terra cotta.
Project Schedule
Program Approval
A/E/ Selection
Bid Date
Start of Construction
Substantial Completion
Final Completion
Date
11/2008
12/2008
05/2009
06/2009
03/2010
07/2010
AGENCY CONTACT: Ted Crawford, ted.crawford@wisconsin.gov, 608.266.1674
Deering/FY09 Building Comm/State Capitol Dome Moisture Repairs Phase I/ State Capitol Dome Moisture Repairs Phase I