$10 million repair project starting on Iowa Capitol's crumbling golden dome

A $10 million repair project has begun on the Iowa Capitol's golden dome, one of the most iconic landmarks in Des Moines.

Construction crews have started preliminary work in recent days on the restoration project, which isn't scheduled to be completed until the fall of 2018. Scaffolding will be installed to allow repairs on the exterior of the structure, and tours inside the dome will be halted until restoration is finished inside the building, said Mark Willemssen, an Iowa Legislature facilities manager.

A large crane has been set up on west side of the Capitol and chain link fencing has been installed in some areas. The project was authorized by the Legislature last year, but the start of work was delayed until this spring to allow time for architects to prepare detailed drawings and specifications.The contractor is Neumann Brothers of Des Moines.

The dome suffers from failing joints and cracks in the mortar, which are compounded by moisture problems from water leaking from outside and from humidity from large crowds inside, Willemssen said. Extensive tuck-pointing is needed, although the dome will not need to be re-gilded with gold leaf.

If the work goes as planned, Willemssen said most of the scaffolding will be removed from outside the dome later this year.

Sen. Matt McCoy, D-Des Moines, who was involved in authorizing money for the project last year, said there is no question the repairs are needed.

"The moisture had eroded the masonry in the dome area, and it was almost becoming like sand. When you touched the mortar, it essentially just fell apart," McCoy said. "The importance is that this will protect and preserve the dome for the next generation of Iowans. ... This is an Iowa treasure, and protecting the dome and doing all that we can to make sure that it stands for another 100 years is really the objective here."

The Iowa Capitol was constructed between 1871 and 1886 in a modified and refined Renaissance style of architecture. The center dome is made of iron and brick and covered with real 23-carat gold. The dome rises 275 feet above the ground floor. Four smaller domes rise from the four corners of the Capitol. Money for the dome repairs is coming from funds left over from bond issues.

Iowa became a state in 1846, and the first General Assembly recognized the capital should be farther west than Iowa City, according to an official state publication. Amid rivalries, Jasper County was chosen and then rejected. In 1854, the fifth General Assembly concluded the Capitol should be "within two miles of the Raccoon fork of the Des Moines River."

The exact spot was chosen when Wilson Alexander Scott gave the state 9.5 acres where the Iowa Capitol now stands. A temporary building was used for 30 years while the permanent structure was being built.