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.

Paint Analysis for Historic Buildings

Hey, that’s a neat old building. I wonder what it looked like new?”

Gathering paint samples for analysis
Gathering samples for analysis

I recently had the good fortune of attending a course at the National Center for Preservation Technology and Training in Natchitoches, Louisiana on paint analysis for historic buildings. The Town of Natchitoches is in northern Louisiana and is situated around historic cotton plantations. The movie “Steel Magnolias” was filmed in Natchitoches during the late 1980’s.

The course, Paint Analysis for Historic Buildings, was taught by David Arbogast. Mr. Arbogast is a renowned architectural conservator and paint specialist from Davenport, Iowa. During three intensive days we learned a great deal about the history of applied finishes (paints, stains, and clear coatings), architectural paint chemistry, the proper technique to restore deteriorated window mechanisms, how to collect field samples and analyze them in a laboratory and how to write up the findings.

Analyzing a paint sample to identify the paint layers and colours
Analyzing a sample to identify layers  and colours

During the second day, we collected 43 paint samples from the nearby Old Courthouse Museum. Most of our samples were smaller than the diameter of a pencil—more than enough for laboratory analysis. Using an optical stereo microscope, we examined each one. From these tiny specimens we were able to determine the number of layers of coatings applied to a particular area, and the colour of each layer. Observing the microscopic lines of atmospheric deposits (mostly soot and dirt) we established how frequently the building was painted. We documented each colour identified according to the Munsell System of Colour, a standardised colour palette book that does not change with time and fashion. It was amazing to see that such tiny samples could offer so much information about how a building evolved over its life.

It was a very intensive three days, but what I learned will be invaluable to my work as an architectural conservator or to anyone interested in knowing the evolution of coatings and colours used on their historic building.

Written by: Jim Nakonechny, Senior Restoration Officer

You don’t live in a cave—so why the stalactites?

DSC_9011
Ice damming challenges

Darn Ice-Damming.

It’s been a long winter, but summer is almost here. The lengthening days signal that it is time to start planning some of the regular maintenance every building needs to deal with the winters still to come. Have you noticed long, heavy icicles hanging from your home’s eaves this winter? If you did, the building likely has a problem with ice damming. Examining the damage, effecting repairs and solving the underlying problem should be a priority.

Ice damming happens when warm air that rises in a building suddenly hits the frozen roof. Any snow or ice sitting on that roof melts and runs towards the eaves—where it promptly freezes again. That ice plugs the eavestroughs, overflows (hence the icicles) and is often forced into the roof itself. Many think that icicles hanging from the eaves are beautiful, but the water forced into the roof can wind up in the ceiling and walls. Ice damming is often the root cause of problems with mould, rot and even structural failure.

There are several ways to minimise ice damming. Keeping snow off the roof prevents it from melting in the first place. Heat cables can be installed at the base of the roof to prevent water from refreezing at the eaves. However, if the roof is nearing the end of its useful life and in need of rehabilitation, this is an opportunity to address the underlying problem.

Ice damming is indeed a symptom of a larger problem with the roof. Those long, heavy icicles are a sign that a roof lacks proper insulation or ventilation. The more heat escaping from the attic, the more quickly the snow on a roof will melt. The more poorly ventilated the roof is, the less likely the rising heat will dissipate evenly.

What to do? Careful observation and a little research is always the first step: you cannot solve a problem you don’t understand. Get into the habit of comparing the amount of snow on your roof to the amount on the roofs of other buildings in the area. If snow disappears more quickly from your roof, that could be evidence of poor insulation. If the amount of snow is unevenly distributed a few days after a snowfall, your roofing system may be poorly ventilated.

How to fix the underlying problem? Since ice damming is caused by melting snow that quickly refreezes, a solution will limit the amount of heat escaping through the attic while distributing the heat that does inevitably escape evenly across the roof. Be careful—adding too much or the wrong type of insulation or installing it poorly creates its own problems.

Insulating a roof in the wrong way can easily compromise the ventilation. The areas where a roof meets the walls will always be warmer than the peak. Proper ventilation moves heat from the warmer to the cooler areas of the roof, limiting the potential for the snow and ice to melt. In older homes, a lack of ventilation is quite common: exposed rafters or decorative boxed-in soffits with crown mouldings often restrict air flow within the attic. There are ways to improve ventilation that do not comprise the heritage value of your home.

It’s always a good idea to consult a professional. An architect or roofing engineer can help you evaluate the benefits and drawbacks of different solutions. You must consider all of the variables and materials that compose a roof before implementing a solution:a roof is not just a layer of shingles but a system complete with external and internal components.

Written by: Carlo Laforge, Heritage Conservation Adviser.

We’re Cracked!

The Challenge of Fixing Foundation Flaws 

Foundation Problems (minor)Every building has a foundation, whether it’s above ground or below ground, concrete or wood.  A foundation is the first building element constructed and therefore it is very important to get it right.  Any errors or flaws will manifest, either relatively quickly for a major mistake or over time for a subtle error.

In Alberta, most heritage building foundations are poured-in-place concrete.  Some foundations are comprised of concrete blocks while others are comprised of a mixture of masonry units (i.e. fieldstones, cut stones and brick).  Now and again flaws such as cracks and spalling (the breaking or splitting of surface layers) manifest themselves.  It is not recommended to ignore these deficiencies as, depending on their severity, they can be repaired fairly easily.  If left unrepaired, the severity will increase.

Some foundation flaws/cracks are inevitable and often show up early once the building is finished and the full weight of the structure is at rest.  Others appear once the structure above and the ground beneath have fully settled.  Depending on the ground composition and the depth of the foundation (foundation depths vary, such as a full basement vs. a crawlspace), these settlement cracks will vary in size.  And finally, some cracks will suggest that something is wrong with the foundation but if addressed in a timely manner may still allow a reasonable/affordable correction to be implemented.

Foundations can also be damaged by water and seasonal frost heaving.  To minimise this damage, ensure that the grade slopes away from the building with sufficient drainage to move the water away.  Frost protection can be achieved by embedding the ground with high-density foam insulation to prevent the frost line from going under the foundation if it is less than four or six feet (1.2 metres or 1.8 metres) or by underpinning the foundation to a depth greater than the frost level in the area (this is usually at least 1.8 metres in Canada, which is one of the reasons why we tend to have basements).  If one has to dig that far down to protect the foundation against frost then one might as well as make it a usable space.

The Standards and Guidelines for the Conservation of Historic Places in Canada  contains a number of sections related to the conservation and repair of foundations: check out the general recommendations of “Structural Systems” (4.3.8) under “Guidelines for Buildings” and for material specific information read about “Masonry” (4.5.3) and “Concrete” (4.5.4) under “Guidelines for Materials.”  Depending on the type of structure and level of intervention, other sections of the Standards and Guidelines might also need to be reviewed.

The following images summarize some of the types of foundation cracks and the potential solutions that might be proposed:

Type of crack: Minor – surface only, usually located at higher stress points.
Type of crack (minor): surface only, usually located at higher stress points.
Proposed Solution: Minor  - Concrete patching, parging or an injected filler product
Proposed solution (minor): concrete patching, parging or an injected filler product.
Type of crack: Medium - showing signs of structural failure and weakness such as spalling.
Type of crack (medium): showing signs of structural failure and weakness such as spalling.
Proposed Solution: Medium - Containment – pour new foundation wall against the old to stop the structural failure.
Proposed solution (medium): containment – pour new foundation wall against the old to stop the structural failure.
Type of crack: Significant - structural failure has occurred and structure becoming increasingly unstable.
Type of crack (significant): structural failure has occurred and structure becoming increasingly unstable.
Proposed Solution: Significant - Full foundation replacement.
Proposed solution (significant): full foundation replacement.

Notes:

  • Minor and some medium types of cracks can usually be repaired by foundation specialists.
  • Some medium and all significant level cracks will require the services of a structural engineer.
  • Due to the specialty of the mixes and structural nature of foundations it is best to seek certified and experienced masonry/concrete professionals to help resolve the situation.

Ultimately, foundations perform a crucial function for our buildings.  Whatever problems occur they will begin to transfer to the rest of the structure if they are not addressed.  For designated provincial and municipal historic resources the costs incurred to address these issues, whether they be minor, medium or significant (including any engineering costs), would be eligible for grant funding through the Alberta Historical Resources Foundation’s Historic Resource Conservation program.

Written by: Carlo Laforge, Heritage Conservation Adviser.

Frost is in the air!

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.

If you have any technical questions related to the conservation of your historic place, submit a comment in response to this post. We would be happy to prepare a response.

It’s bad to clad!

Property owners occasionally ask whether historic wood windows and trim can be clad in sheet metal to both eliminate maintenance and protect fragile historic material. As conservation advisers, we discourage cladding since it removes, in effect, a character-defining element from the building, and cladding raises maintenance issues of its own.

Tempting though it may be, simply covering up deteriorated areas can ignore the causes of deterioration, leaving underlying moisture or other problems to continue their destructive work within the structure.

Wood sills, as an example, may be weathered rather than actually rotted and can often be treated relatively easily and economically with wood epoxy repairs. Once repaired, the repainted wood is stable, rot-resistant and easily maintained.

Sheet metal cladding, on the other hand, takes skill to properly detail, fit, and install so that it drains properly. Once installed, claddings often rely on caulking to seal open edges. Caulking can attract dirt and, like the painted surfaces it conceals, needs to be maintained and periodically replaced. Perhaps most important, clad wood is no longer exposed to the drying effects of the sun and circulating air, so that if water does gets beneath the cladding, as it likely eventually will, deterioration can occur rapidly and unnoticed. Better the devil you know…

This isn’t to say cladding is always inappropriate: it may be a valid means of adding a weather detail missing in the historic element while minimizing impacts on heritage value. In general, though, it’s preferable to have an authentic original material that you can appreciate and easily maintain.

Written by: Fraser Shaw, Heritage Conservation Adviser.

Not Just a Pane: Historic Windows

 

Windows are an integral part of a building system. They transmit light, control heat flow, are a means of egress, frame exterior views, and are significant elements that contribute to the design of the building. Windows are complex units and are made up of many different components that can be decorative, functional or both. 

Why are historic windows important? 

Historic windows are often character-defining elements. Character-defining elements are the materials, form, location, spatial configurations, uses and cultural associations or meanings that contribute to the heritage value of a historic place and must be retained in order to preserve its heritage value. Furthermore, historic windows are elements that directly reflect a site’s craftsmanship and design and are usually constructed out of particular materials. They are usually quite detailed and in some instances retain original glazing units.

Left to Right: Beatty House, Rimbey; Cronquist House, Red Deer; Pine Lake Holy Trinity Church, Pine Lake

Common misconceptions about historic wood windows 

On a daily basis I field questions about the replacement of historic wood windows. A typical case is a historic site with historic windows that have not been looked at in some time and have deteriorated to some extent due to weathering. A common misconception is that replacement of these historic windows with a modern unit is cheaper and will increase the thermal efficiency of the building through higher R values. 

Research in performance standards for timber sash and case windows in Scotland has taught us that estimated costs including painting of window components, repairing damaged putty and re-caulking where necessary within a regular maintenance program eliminated the cost of a major restoration project every five years. Another thing to consider is that modern sealed units, when they fail are not maintainable and must be replaced outright. 

It is also interesting to learn that a single glazed window in conjunction with an exterior or interior storm window is comparable to a modern sealed unit. A single glazed window has an R value of 0.6 while a single glazed window with wood storm has an R value of 2.0. The top of the line triple glazed window with low E coating and argon has an R value of 3.5. Overall windows in general are thermally inefficient in comparison to a typical wall with 4” batt insulation that has an R value of 12. 

Planning for historic wood window conservation work 

When planning for any conservation work we always take the approach of minimal intervention. Preserving historic material and maintaining historic material is the first step and outright replacement, if necessary, is the last option. 

In most cases simple epoxy repairs to wood, adequate prepping of the wood surface (manual scraping), the application of an appropriate primer and brushed on layers of exterior paint is all that is needed to repair historic windows and to prevent deterioration.

For more severe cases, putty replacement, replacement of broken or damaged glazing, and dutchman (splicing in of new wood) may be required. 

Conclusion 

  • Historic windows have heritage value.
  • Historic windows have demonstrated good durability and maintainability.
  • Always assess and document each window before proceeding with conservation work.
  • Compile historic photographs and refer to the Statement of Significance in your planning process.
  • Minimal intervention should be the first approach.

Remember, you can save on costs and achieve the same thermal efficiency through conservation.

Written by: Ophelia Liew, Heritage Conservation Advisor