The Latest
Dear John: Tempered vs. Laminated Glass
Blackburn Architects’ Senior Project Manager Ian Kelly answers questions about the glass used in equestrian facilities.
Q: Dear John,
I’m overseeing renovations to a barn in the cold climate near Quebec. To improve the barn’s functionality, safety and ventilation, we are converting the windows to double-pane, energy efficient, glass.
Please help:
1. Do you recommend a pane of tempered glass on one side of the spacer bar and regular laminated glass on the other side? (Editor’s note: a spacer bar, sometimes known as a profile, is the continuous hollow frame which separates the two glass panes in a double glazed window.)
2. Is it better to have tempered glass throughout including the laminated glass?
3. It appears that laminate glass consists of a clear plastic laminate sandwiched by glass on both sides. Do both glass pieces that make up the laminate glass need to be tempered?
4. Do both panes of glass making up the double glazed unit need to be laminated?
5. What minimum thickness of glass and minimum airspace or spacer bar size do you recommend?
Thanks so much for your help,
Barn Manager Trying to Get It Right
A: Dear Barn Manager Trying to Get It Right,
1. We recommend that the glass used in equestrian structures be tempered throughout, including the glass that is laminated. The tempering and lamination processes do separate but similar things: They create safer glass for people and livestock. Tempering makes the glass break into small chunks as opposed to slivers and sharp pieces, while the lamination gives the glass a slightly greater resistance to breaking, and keeps the glass in place when and if it breaks. Both serve to make it safer around the horses if a window should break.
2. If horses have access to both sides of the glazing unit, then we recommend both sides of all glass should be laminated and tempered. If cost is an issue, I would stick with everything being tempered and omit the lamination. I say this because laminated glass does not always age as well as tempering. This doesn’t happen in every case, but the laminate can shrink and pull in from the corners of the glass, and eventually become visible over time. We prefer tempering.
3. Any glass that is exposed to the horses should be either tempered or laminated at a minimum. If the horses have access to both sides of the doors, yes, both panes should be protected in one way or the other, or both.
4. You should work backwards from the depth of frame that you have, minus about 1/4”. Working with the glass manufacturer will determine what they have available for the spacer sizes. The more airspace you can allow for the better, but each manufacturer already works with a few different size spacers. Use the largest one that still allows the glazing unit to fit within the frame.
You also should consider some other factors pertaining to glass in cold climates, and request glass that meets the following:
You want glass with a high solar gain, and low emissivity.
1. The glass should have a Solar Heat Gain Coefficient (SHGC) around 0.55
2. The glass should have a U-value of less than 0.33
3. The glass should have a higher value Visible Transmission (VT)
4. Use double-paned glazing unit with low-e gas that has a vacuum sealed gasket between the panes of glass. The pocket between panes of glass is filled with an insulation gas, most typically argon.
5. You may also consider using low emissive (low-e) glass panes. Low-e prevents the transfer of heat from warm to cold. So if you do, the low-e coating (typically a metallic oxide) should be on the outermost side of the innermost pane of glass.
There are pros and cons that should be considered with each option. For instance, with #4, over time and if the gasket seal fails, you can begin to see condensation between the panes of glass. Whereas with #5, you may be able to see the coating from certain angles, especially if you are wearing polarized sunglasses.
Since the advantages are a bit more obvious, and similar to one another (i.e. tempered vs laminated, and low-e gas vs low-e coated glass), here is a summary of some of the disadvantages to each option:
tempered only – glass may still shatter (in harmless pieces) and fall to the ground
laminated only – laminate can discolor over time and shrink in from the corners of the glass
low-e gas filled glazing unit – if the gasket fails, condensation can form in between the glass
low-e coated glass – may be visible in certain light conditions, or when wearing polarized sunglasses. You can sometimes see this on automobile glass.
My suggested starting place would be tempered glass, meeting the SHGC and U-values recommended above. I would then lean toward #5 – low-e coated glass, since with #4 you can expect the gaskets to fail at some point, and then the glazing unit would need to be replaced again. If the coating of the low-e coated glass is too “visible”, then low-e gas may be the better option, with the expectation that you may need to replace some of them again in 10 to 20 years, if and when the gaskets fail.
Dear John: Polycarbonate Panels
John Blackburn answers your questions about barn design.
Q: Dear John,
Long ago you were kind enough to give me a bit of advice about planning a barn. We got started last spring, but were waylaid by an evil contractor who put the barn in the setback, with poles only 18″ in the ground, and a drainage system two feet too high to catch any water. On top of that, he dumped 130 truckloads of bad, unnecessary fill, and built a retention pond that is 36% too small – UGH! Luckily it was all easily documented by the project’s engineer so we are able to recoup a little of the money laid out.
So: moving along, we deconstructed the barn, redid all the drainage, and turned to a pre-fab barn.
The new building is a 60×120 raised center aisle structure. I requested open sidelights and a ridge vent to help keep airflow going in the soggy, humid climate in the northwestern US. The stalls almost always will be open to an 8ft shed eave and attached paddock. Their fronts are composed of lots of steel mesh — so lots of air.
I’m NOW STUCK. I feel quite stuck because no one around here understands your way of doing things. I’m trying to incorporate what I learned over the years from your publications.
Please help with my roofing situation:
The roofing is 26g boxed rib metal panels. I requested polycarbonate panels be incorporated for natural light. The question is whether it’s unwise to let the whole raised center be polycarbonate, or go with only one light panel per 12ft section–and whether it’s crazy to use clear vs opaque white panels. (Most weeks out of the year it is damp and grey and cold here.) The barn company is in hot California so they think the whole idea is nuts.
If moved to offer an opinion, please know I’m already grateful.
Thank you,
Northwest Endurance Rider
A: Dear Northwest Endurance Rider,
I understand why you resorted to prefab because you’ve been thru a nightmare. However, prefab barns can be hot boxes in the summer, and don’t always provide adequate controls for natural light and ventilation. Pre-designed, pre-engineered buildings are typically designed the same for all areas of the country and no two areas of the country are alike nor are the sites. Environmental and weather conditions can differ dramatically so a prefab building designed to fit all sites just does not work best for the health and safety of stabling for horses. But I understand. You’ve selected the barn you want, now my advice is you should provide for as many options as you can for control of natural light and ventilation.
You mentioned a 60 ft x 120 ft raised center aisle structure. How many rows of stalls are there in the barn? The best arrangement is to have one center aisle and a row of stalls along each side of the barn. The 60 ft width sounds like there are two main aisles with rows of stalls on both sides of each aisle. That would mean two of the rows of stalls are back to back and not on the exterior where they get adequate ventilation and natural lighting.
The 8 ft shed eave is too low in my opinion. I use 12 ft as a minimum though 10 ft may work for smaller horses and if there are no obstructions below the roof. However, there are usually lights, fans, beams, etc. that drop down and they can be a danger to horses.
I like the use of translucent polycarbonate panels. Translucent, not clear, as it breaks up the light and hides the dirt that accumulates on the skylight over time. Providing polycarbonate across the center aisle sounds nice, but I’m unsure how it will look on the barn design you selected. If you’re putting a skylight over the raised center aisle roof, what is on the face of the raised center portion? There is usually some sort of glazing or louver for venting. It will be important that these elements complement one another. Thanks for the question and I hope this is helpful.
Good luck!
John
Back to School, Part II
Checking back in to report what’s been happening at Clemson’s School of Architecture & Studio Appalachia.
In case you missed it… Studio Appalachia is a collaborative, project-based graduate design studio between Clemson’s school of architecture and its department of landscape architecture. The Studio is directed by associate professors Dan Harding and Paul Russell. Studio Appalachia targets issues such as: accessibility to natural resources, sustainable building strategies, and approaches to long term visioning and planning.
I was asked to participate in this year’s studio because it involved horse facilities, specifically re-envisioning the Clemson University Equine Center (CUEC). With aging facilities that are well-used and well-loved, I knew it would be fascinating to see how these talented students created a fresh program for the facility. The teams of architecture and equine business students (a new twist for the studio) have spent the last several weeks immersed in detailing the site and facility requirements, learning about design issues unique to equines.
Teams consisting of three to four students conducted rigorous research, made several site visits, interviewed user groups, studied topography, considered land, sun, wind, circulation paths and traffic flow to create detailed and well considered Master Plan Studies and Field Reports.
Referencing the evolving formal and material contexts of Southern Appalachia, the four teams stated as goals to “improve circulation, establish organization, and enhance the (existing) ecology of the historic Clemson farm. To them, as one team eloquently stated, the CUEC is more than a farm; it is an institution that showcases the prestige of the university, and embodies the history, strength, and energy that the equine program was founded on.
The preliminary master plan schemes presented earlier in October were successful in developing goals and considerations for further study. The studio presents preliminary concept designs later this week and I’m looking forward to the big reveal.
After Horse Racing: What Happens to Los Alamitos Land If Track Closes?
Last week the Paulick Report featured a story on worries over the possible closing of California’s Los Alamitos track (http://www.paulickreport.com/news/the-biz/life-horse-racing-happens-los-alamitos-acreage-racing-ends/)
As a Board member of the Equine Land Conservation Resource, a national organization dedicated to saving land for horses and horse-related activities, it’s disheartening to hear of the potential loss of a thriving racing venue for what will no doubt become another strip mall and urban sprawl.
I have been concerned for years about the loss of race tracks, especially older ones in the inner city or suburban locations that are under pressure to close.
Santa Anita was considering reducing their stable area several years ago and selling land to an adjoining commercial shopping mall. There was pressure to shut down Pimlico (an inner city aging track) and move the Preakness to Laurel Park. Suffolk Downs in Boston is under similar pressure. The list goes on and on.
And of course the answer for many race tracks has been to add casinos, which do nothing for horses or horse racing except cheapen it. Racing is a great spectator sport. Look at racing in Europe, especially in England (Goodwood and Ascot are two prime examples) where horse racing is an enjoyable event not a place where desperation fuels gambling.
The Los Alamitos track supports the horse economy, preserves open space, diversifies the suburban environment/landscape/streetscape/economy and preserves the equine heritage of the site and area.
There are heartening success stories. When Illinois’ Balmoral Park hosted its last harness races at the end of 2015, a New York company, Horse Shows in the Sun, purchased the 200-acre site, and after a significant investment is preparing the grounds for show jumping competition starting next spring.
I’ll be writing more about this in the months to come. To learn more about the Equine Land Conservation Resource and its mission, please visit their website at www.ELCR.org to become a member and get involved.
Back to School
John Blackburn elected to Maryland Horse Council Board
Newly elected to the Maryland Horse Council’s Board of Directors, John Blackburn will serve as a voting member beginning July 2016 through June 2018
Healthy Stables By Design
Healthy Stables by Design restocked on Amazon.
Ask the Barn Expert
Watch as John gives viewers advice about their barn projects on the popular series Wild About Barns.
Designing For Extremes: Snow & Ice
Coming off the heels of a truly epic storm for the Washington D.C. area (and most of the east coast!), I thought I’d take a moment to address how design techniques can help barns “weather” extremes.
In the United States, the upper northeast regions through to the Midwest are prone to experience weather extremes in the form of snow and ice. While we cannot entirely “weather proof” a barn, we can make it more resilient to some of the more damaging effects of weather phenomena.
The roof of your barn needs to be able to:
- Withstand the weight of snow and/or effectively shed it
- Prevent or reduce the formation of ice dams
- Redirect “roof avalanches” from sliding into high traffic or poor drainage areas and also reduce associated noise that could frighten the horses.
In addition to contributing to the Bernoulli principle I incorporate for natural ventilation, steeply pitched roofs also contribute to effective, gradual roof shedding and the redistribution of snow load. Ideally the pitch should be between 4/12 and 6/12 to get the optimal shedding effect (although, we generally try to keep pitches at 7/12 or more to take full advantage of the Chimney Effect and Bernoulli principle for natural ventilation)
Roofing material will also factor into how the snow will shed. Metal roofs are excellent as they are smooth and slick. They will also stay colder longer; reducing the likelihood that snow will melt and form ice dams (more on this below). Snow will shed from a metal roof even if the pitch is lower. Shingled roofs, however, will slow down the shedding process by “holding on” to the snow and allowing it to stay in place and accumulate. Consider a steeper pitch if you prefer a shingled roof as it will facilitate the shedding process over the rougher material.
Winley Farm – Millbrook, NY
Now, you might be saying to yourself, “Well, the snow is off the roof…but it’s all over the place! Now what?” Including strategic roof overhangs will complement the steeper pitch by helping to distribute shedding snow away from exterior walls and out of traffic and poor drainage areas. Be wary though, snow sliding off roofs can be noisy and frightening to horses, not to mention dangerous if it falls on you! Snow guards on the roof can help reduce the noise associated with shedding snow and keep huge sheets of it from falling on (and potentially harming) 2 and 4 legged passersby. Gabled dormers over entryways can also be useful. They help to direct snow off to the sides.
Beechwood Stables – Weston, MA
Snow guard
Ice dams are another unfortunate side effect of snow-laden roofs. An ice dam forms when the underside of the roof gets warm enough to thaw the bottom layer of snow sitting on the other side. The water makes its way down to the eave where it refreezes, eventually growing into a mound of ice. As the ice dam gets larger, it can pull the shingles and edges up allowing water to get through and into the insulation and walls. Water damage then wreaks havoc on the interior of the barn. The ice dam could also break off the eave and take pieces of the roof with it or fall on passersby. Sure, there are ways to deal with ice dams once they’ve formed, but natural ventilation can help prevent them upfront. Natural ventilation keeps the underside of the roof within 10 degrees of the outside temperature, which aides in keeping that critical layer of snow right on top from thawing and running down towards the eaves.
Damn ice
Site and circulation planning can help prevent and/or reduce the impact of icy conditions around equine walkways. In the interest of horse safety, I try to design site circulation so that horses do not need to move over asphalted areas intended for trucks and service vehicles (there are other benefits associated with that as well). Asphalt is not great for horse’s knees, generally, but it is particularly problematic when wintery conditions lead to the formation of “black ice” — a thin sheet of ice over the asphalt that can be imperceptible to the horse or persons walking on to it. Horse pathways in and around the barn should include porous footing that absorbs and carries moisture away quickly. Presently there is no way (that I know of) to prevent pastures from freezing over, but you can maintain a dry paddock or “sacrifice” lot where your horses can be turned out when pastures have been effected by inclement weather. Paddocks with considerable slope can be particularly hazardous when they freeze over. That’s when a “level” dry lot can be very useful!
Caution!
As many on the east coast found out this past week, there is only so much preparation you can do in a couple of days before a storm hits. You, your horses, and your barn will benefit from built in preparation.