Frost is in the air!

This post was originally published on RETROactive on October 31, 2012. However, since we live in Alberta, this topic is almost ALWAYS relevant – what to do about frosty windows!

With winter coming, some owners of historic places might be witnessing the formation of frost on their single pane wood windows and storms, most notably on the second storey. The reasons for this will vary and subsequently so will the solutions. Generally speaking, a little frost now and again should not harm the window frame but a more persistent formation will saturate the surrounding material and, in the long run, potentially cause significant damage. Should this be the case, ignoring the situation is far from the recommended solution.

Frosty window. Note the closed storm window vent cover. During the winter it should be open.

So what is one to do?  The first step, as with any intervention on a historic place, is to develop an understanding of the problem.  What is causing frost to form on the window? The answer: warm moist air comes in contact with the cold glass and condenses, which then freezes on the surface. So how does one mitigate this? Should you let the house freeze so that the interior temperature matches the outside, or should you turn the house into an oven to eliminate any and all moisture in the air? Obviously, neither scenario is plausible.

So what is one to do – replace the windows?  Speaking from a heritage conservation perspective, replacing authentic historic windows would be the equivalent to someone shaving their head bald because they found a grey hair. Historic windows have, in my experience, proven themselves to be longer lasting than any modern window and can continue to serve their function with proper care and maintenance, while modern windows wear out and routinely need to be replaced.

As air moisture is the general cause of frosted windows, controlling it would appear to be the most appropriate approach. However, there is more than one way to control moisture during the winter. One can control moisture levels with a dehumidifier, or by preventing it from reaching the cold glass with weather stripping techniques. As well, one could better manage the presence of moisture with exhaust fans and insulation. Any combination of these efforts will help to reduce the frost on windows but it should also be noted that there are pre-existing systems that should be taken advantage of in regards to this problem.

Storm windows traditionally have three holes at their bases with a flap cover. During the winter, these should be open to let moisture and condensation escape. When bugs arrive with spring, close the flap. Double hung windows generally have locks where the sashes meet – use them to tighten the window and reduce air leakage. Should you decide to proceed with a form of weather stripping, concentrate on the interior side of the window and allow the storm window to breathe. This will create a micro-climate (similar to the ventilation in one’s roof), which should help prevent frost and therefore better sustain and protect the window.

Hopefully, the preceding information will be useful for those who might be dealing with frosty windows. There are many articles on the Internet, which tackle this issue and propose similar, different and additional solutions ranging from “free to expensive”.  As a Heritage Conservation Adviser, my advice, and that of the Standards and Guidelines for the Conservation of Historic Places in Canada, is to start with the minimal approach.  With any luck, that is all that will be needed.

Written by: Carlo Laforge, Heritage Conservation Adviser.

“Isn’t it good, Norwegian Wood?”

So, a colleague of mine here in the Historic Resources Management Branch recently returned from a course on wood conservation in Oslo, Norway.

While he didn’t find out why John Lennon lit a former lover’s house on fire as the song strangely suggests, he did attend the 2018 International Course on Wood Conservation Technology (ICWCT). A biennial course that gathers academics, professors and scientists from around the world (including two from Canada) to deliver lectures, ICWCT also combines this with field work and theory centered on the practice of wood conservation.

1280px-Borgund_Stavekirk,_Norway
The Borgund Stave Church in Lærdalen, Norway was built just before 1150. From the Middle Ages up until the beginning of the twentieth century the use of pine tar was restricted to the protection of churches, since it was both time-consuming  and expensive to produce. This goes a long way towards explaining why outdoor woodwork on the stave churches from the twelfth century which has been protected with pine tar is preserved in an excellent condition. Norwegian church accounts reveal that the local farmers and villagers were obliged to apply fresh tar to the external walls of the stave churches at ten yearly intervals*. Photo by: AzaToth

Heritage Conservation Technologist Evan Oxland went to Norway to learn more about technical and theoretical aspects of wood conservation, as well as what other contemporary international approaches there are out there. He was the only Read more

Another Log in the Wall: Preserving Historic Timber Architecture in Alberta

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The uncoated timber Slemko Barn at the Ukrainian Cultural Heritage Village, a variety of building components representing different species, thickness of section, and orientation of wood grain. Source: Evan Oxland, 2017

“Sustainability is not possible without durability […] Once constructed a building becomes a machine that ‘needs to be fed’.” -Joseph Lstiburek, 2006

In Alberta, there are hundreds of thousands of square feet of raw uncoated timber used in historic architecture, including farmhouses at the Ukrainian Cultural Heritage Village and log churches at Historic Dunvegan. Penetrating oils and wood coatings help prevent the primary causes of wood deterioration, but when these historic structures must be preserved in perpetuity, how do you assure the building material will last when it was originally built to make it through only a decade or two?

This is where Alberta Culture and Tourism’s Conservation and Construction Services comes in. Read more

Dealing with Graffiti at Historic Places

Historic places are unfortunately fair game for graffiti attacks – sometimes especially so when these places are visible and widely recognized landmarks. Defined as writing or drawings scribbled, scratched, or painted illicitly onto walls and other surfaces, graffiti from a heritage conservation perspective is an intervention to be removed or reversed. It clearly differs from old markings that are an acknowledged and legitimate part, or “character-defining element”, of a historic place. Examples of the latter are prisoners’ inscriptions etched into the basement cell walls of the Cardston Courthouse or, on the opposite side of the law, North West Mounted Police members’ initials carved into the sandstone outcrops overlooking Police Coulee at Writing-On-Stone Provincial Park. These special cases contribute to heritage value rather than obscure or detract from it. Read more

Rebuilding the Beehive Kiln

The first steps out onto the dome of the beehive kiln are a bit unnerving, with only a thin shell of tightly-fitted bricks supporting a small group of us above the void below. Domes structurally similar to this have been around since antiquity – many notable examples still survive – but it’s reassuring to know that scaffolding inside the kiln will prevent a painful and possibly career-ending collapse.

Kiln No. 2, one of four historic beehive downdraft kilns at Medalta Potteries, is a circular drum roughly ten metres in diameter with brick exterior walls surmounted by the dome and a tall central stack. Encircling the walls are wide adjustable bands of corroding steel which held the kiln together as it expanded and contracted and attest to the rigours of the firing process. Medalta’s beehive kilns historically fired a wide range of ceramic products and now serve as distinctive classroom and exhibit spaces.

Beehive dome interior, Medalta Potteries, 2011.
Beehive dome interior, Medalta Potteries, 2011.

Read more

Replication of Long-Missing Features Completes Restoration of Fort MacLeod’s Grier Block

Grier Block after rehabilitation was complete (July 2014).
Grier Block after rehabilitation was complete (July 2014).

The Grier Block, built in 1902, was one of the first and largest commercial buildings in Fort MacLeod. It has one of the only pressed-metal facades in western Canada, highly decorated with an elaborate cornice and pilasters (columns between the window bays). Peter Maas recalls that by the early 2000s, when he and his brother Hans purchased it, the once-distinguished building was “pretty dilapidated.” The brothers spent seven years on a major rehabilitation (working full time, without pay, living on the premises) that brought the building back as a prominent and attractive contributor to Fort Macleod’s historic downtown. They recently added some long-missing and key elements, returning the building to its full glory.

The rehabilitation work included adding insulation and making other upgrades to the building envelope (the outer shell separating the interior from the exterior), accurately replacing the historic windows and frames, and preserving the original pressed-metal facade still present on the upper floor. (For a detailed account of the rehabilitation of the Grier Block, see pages 6 to 9 of the Standards and Guidelines for the Conservation of Historic Places in Canada.)

Unfortunately, the first-storey cast-iron pilasters had been missing since the 1960s, so the brothers only restored what was there at the time. It was fairly common to remove decorative facades from commercial buildings during the 1950s, ’60s, and early ’70s, says Fraser Shaw, the Heritage Conservation Advisor for Southern Alberta. Ground-level elements corrode more readily. Also, at mid-century, out-of-fashion ornamented facades were often modernized at street level, as this one was, with expanses of plate glass windows with plain surrounds.

The brothers were never satisfied with what they considered an incomplete restoration: “That was the only piece to the puzzle that was missing,” Peter says. “We’ve gone 100 percent on everything else, and that was the only thing that was left to attend to, so it was important to us to have that finished.”

The Grier Block in 2001, many years before the restoration began (November 2001).
The Grier Block in 2001, many years before the restoration began (November 2001).

Now—thanks to their perseverance, resourcefulness, and the lucky confluence of the right people at the right time and place—those first-storey pilasters have been replicated and are back in place. It’s “the crowning touch…the icing on the cake,” says Fraser. The building is designated as a Provincial Historic Resource, so his role during both the original rehabilitation and this project was to verify the historical accuracy of the proposed changes and monitor the work.

During the rehabilitation project, the architect in charge, Robert Hirano, made an important discovery: the building has a Mesker Brothers facade. In the late 1800s and early 1900s manufacturers introduced mass-produced prefabricated building components made from sheet-metal panels stamped with decorative motifs and iron elements cast in moulds. These processes provided an easy and inexpensive way to imitate elaborate decorations that historically had been created by craftsmen in more expensive materials such as carved stone. The products were sold through mail-order catalogues and shipped by rail throughout North America. Mesker Brothers Iron Works of St. Louis, Missouri, was one of several companies that created and shipped entire building facade and storefront assemblies. (One competitor was the George L. Mesker Company of Evansville, Ind., owned by another brother.)

A close-up of the rehabilitated metal detailing (July 2014)
A close-up of the rehabilitated metal detailing (July 2014)

Buildings with Mesker Brother facades are plentiful in the U.S. East and Midwest, with numerous Western examples as well, especially in Colorado, Wyoming, Montana, and Washington. The Grier Block has one of only a handful of Mesker facades known to have existed in Canada, with two other Mesker facades installed in nearby Lethbridge—the Metcalfe Block (“Club Cigar”) and Lethbridge Hotel—no longer surviving. Fraser speculates that the developer of the Grier Block might have had U.S. connections, and benefitted from convenient cross-border rail service between southern Alberta and the U.S.

Over the years, Peter Maas had been hunting for Mesker storefronts with pilasters identical to those that once graced the Grier Block, hoping to replicate them. Specifically, he needed to find models for pilasters that are six inches and thirteen inches wide, each with a lower, a middle, and an upper component. All together, 33 individual elements needed to be produced to complete the lower facade.

The original structural steel pilasters of the Grier Block were still intact. Outlines of old paint showed where the ornamental cast-iron pilasters had been, and there were even tool marks showing where they had been hacked off. The owners had historic photographs of the building and the Mesker Brothers catalogue to show how the missing elements should look, and Hirano had produced drawings. “But at the end of the day, you need something that’s full scale and more tangible” to create the accurate, full-sized building elements, Fraser says.

During the rehabilitation work, the Maas brothers hired a carver to create the pilasters out of wood, but the result was disappointing. Later they located a Mesker Brothers building with one of the two needed sizes of pilasters while vacationing in New York State, and used those to create rubber moulds. But because those pilasters had decades of encrusted paint, the resulting moulds lacked definition.

One of the clay model prepared for the casting process (February 2013).
One of the clay model prepared for the casting process (February 2013).

Then everything came together last year when Peter was on vacation in Colorado.

Always on the lookout for Mesker Brothers buildings, he tracked one down in the small town of Mancos, in southwestern Colorado near Durango. It had the six-inch pilasters he needed! While gazing at them, he struck up a fortuitous conversation with a passer-by. That was Collette Webster, a professional potter. She considered how to replicate the pilasters, then came up with a solution.

Remarkably, the building owner allowed them to temporarily remove the pilasters. Collette was able to make plaster moulds of the three sections, and from those make clay templates that could be used for casting the elements in metal through the lost wax process.

On the same trip, Peter found a Mesker Brothers building with the thirteen-inch pilasters on the main street of Telluride, Colorado. In that case, the pilasters couldn’t be removed, so he took lots of photographs. Collette referred to those and to the moulds for the six-inch pilasters to create scaled-up models in wood of the thirteen-inch pilasters. These could then be used to make the necessary plaster moulds and wax models.

Some decorative detailing was still needed. As a potter, Collette was able to craft the missing roundels, florets, and other flourishes out of clay and then attach those shapes to the templates used to create the wax models.

The sections were cast in bronze by craftsman Dimitry Domani at his foundry in Cortez, Colorado, then shipped to Sweetgrass, Montana, for Peter to collect at the border. Domani recommended using bronze rather than the original iron because it has the potential to develop an attractive natural patina over time, whereas the iron would need to be painted.

The Grier Block’s new pilasters are now bolted into place, as they would have been historically, and also welded on “as an extra safeguard,” Fraser says.

“In all, the project seems to have been a lucky convergence of passionate owners, Mesker buildings in Colorado to serve as templates, and a network of local (in southern Colorado) artisans to perform the work where the buildings were,” Fraser concludes. The project was assisted by a matching conservation grant from the Alberta Historical Resources Foundation.

Today the Grier Block is fully occupied. On the first-storey are an insurance and a real estate agency, a stained-glass artisan, a visitor display and offices for Head-Smashed-In Buffalo Jump, and one residential suite; the second storey contains seven residential suites.

“There’s no question that it’s an anchor within the historic commercial district,” Fraser says. And “now the building just resonates with character in a way that it didn’t before.”

“It’s a nice piece of history for the town,” Peter agrees.

Hans Maas, a chef by training, had completed the historic rehabilitation of a smaller Fort MacLeod building as a “hobby,” Peter says, before tackling the Grier Block. Peter had experience constructing new buildings, but this was his first historic rehabilitation project. “I’m addicted to historic buildings now,” he says. “I find the historical projects are way more rewarding…You’ve got to go back to good material and quality workmanship.” He has since purchased and is now hard at work restoring Fort MacLeod’s Reach Block.

Written by: Kerri Rubman.

On the Road and On the Ground Helping Property Owners

Heritage Conservation Advisory Services

Legislature
Scaffolding around the Alberta Legislature Building’s dome (2012).

When Tom Ward stated doing heritage conservation work some 35 years ago, he had no idea if it would lead to long-term employment. But he was hired early in his career to be part of the design team developing the Ukrainian Cultural Heritage Village east of Edmonton (a great learning opportunity, he recalls), and has been involved in heritage projects across the country ever since. Currently Ward is Manager of Heritage Conservation Advisory Services for the Historic Resources Management Branch, supervising five Heritage Conservation Advisers.

The advisers, based in Edmonton and Calgary, cover all regions of Alberta. Their primary job is to ensure that changes made to properties designated as Provincial Historic Resources under Section 20 of the Historical Resources Act are done in ways that follow to the Standards and Guidelines for the Conservation of Historic Places in Canada.

Inspecting the condition of brick masonry (2006).
Inspecting the condition of brick masonry (2006).

The Heritage Conservation Advisers are not the preservation police! In fact, Ward says that the vast majority people who own designated historic resources appreciate the historic character of their properties and are eager to maintain them in an appropriate way. “We take a partnership approach,” he continues. “Even though in the back of our minds we are trying to make sure that the work meets the Standards and Guidelines, our approach is that we are there to help.”

More than half of the advisers’ time is spent in onsite, face-to-face meetings with individual owners, groups, or developers. “Meeting people and seeing the historic places is really the great part of the job,” Ward says. The advisers provide technical guidance on the best ways to accomplish needed work; may recommend qualified architects, engineers, and contractors if needed; and also determine if the property owner might qualify for cost-sharing grant assistance from the Alberta Historical Resources Foundation. They ultimately produce a ministerial approval document package which satisfies Section 20 of the Historical Resources Act and allows the work to proceed.

For example, if a heritage property needs a new roof, the adviser would steer the owner toward the historically appropriate choice of replacing original cedar shingles in kind rather than using cheaper asphalt shingles. “We would specify the kind of shingles the homeowner should use, the exposure, the underlay, the flashing, that sort of thing. Then we can say, this is going to cost you a little more, but it will last you longer and better meet the Standards and Guidelines. You are also eligible to submit an application to the Alberta Historical Resources Foundation to cost-share on that roof so that it brings down your cost to about that of an asphalt shingle roof.”

A historic barn in east-central Alberta being re-shingled (2005).
A historic barn in east-central Alberta being re-shingled (2005).

The result is satisfying for all: “You get very positive, immediate feedback from people when you’re having a conversation over their kitchen table. They really appreciate the technical advice we can give them. And you see the job ultimately done well, ensuring that good conservation happens in Alberta.”

The Heritage Conservation Advisers address the needs of privately owned properties as well as Alberta Culture’s historic sites which are also designated as Provincial Historic Resources. Ward also consults with Alberta Infrastructure when work is needed on Provincially owned heritage buildings administered by that ministry. Recently he was involved in planning conservation measures for the Alberta Legislature Building, especially repair and reconstruction of portions of its dome. Ward and his team also provide technical consultation to other programs of the Historic Resources Management Branch, such as the Municipal Heritage Partnership Program, and meet with property owners considering pursing heritage designation.

The announcement of provincial funding to assist owners of historic properties affected by the 2013 flooding in Southern Alberta will almost certainly mean more “house calls” to owners now undertaking or planning repairs. “It’s going to be an additional workload, but everybody is keen to do it,” Ward says.

He also sees this as a great opportunity to study the effects of flooding on sandstone and fieldstone foundations that are so prevalent in older buildings here, and determine best practices for restoration. The team holds occasional “retreats” to explore a technical issue in depth, through review of professional literature and discussion of their own onsite experiences. The next retreat will, of course, be about addressing flood damage.

The Alberta Legislature Building's dome being restored (2013).
The Alberta Legislature Building’s dome being restored (2013).

Ward says it’s typical of his team members responsible for the flooded areas that all were willing to work overtime, going to flooded areas as soon as they were allowed in, to advise owners on urgent matters, especially the best ways to dry out foundations.

“I’m really proud of the team we have,” Ward concludes. “They are passionate about what they do, and they are passionate about public service.”

Written by: Kerri Rubman.