adding light and ventilation to a horse barn
One of the design considerations in nearly every Blackburn equestrian project is ground surface materials to be used at the exterior of the barn. Hopefully, the information below will be helpful in planning for your barn.
First consideration is it to be porous vs. non porous?
Either will work in this application but you need to build in some sort of drainage system for both, either on the surface or below the surface.
1) Interlocking rubber brick pavers. The Blackburn Architects’ team opinion is that this is the best all-around flooring system for horses because of its durability and aesthetic options. It’s slip resistant and holds up to abuse and in a wide variety of environmental and weather conditions. It can be set loose on a porous or non-porous sub-base or glued down on a firm base like concrete.
2) Oil base chip and seal: Chip seal is a surface treatment used on light traffic roadways/driveways, some lead paths and other areas used for horse or farm traffic. We do not use it very often anymore due to some environmental concerns in some jurisdictions (it typically requires a base layer of asphalt and oil as a binder). Chip seal basically combines one or more layers of asphalt with one or more layer of aggregate. Oil is often used as a binder. Ground up recycled tires are sometimes used as an aggregate. It tends to be slip resistant though it may deteriorate in time. Its life time is typically 5 to 7 years before it needs re-surfacing.
3) Rubber mats (loose laid or glued): This is a good material but should be laid or glued to a concrete or popcorn asphalt base. The mats need a solid base in order to hold in place or remain level over time. Rubber mats can present an aesthetic issue but functionally work well.
4) Stone dust or brick dust: A good material to use but requires maintenance to retain a clean and orderly look. It’s slip resistant and drains relatively well. Not good for plowing conditions unless it is re-spread at the end of the winter season.
5) Popcorn asphalt: An excellent material because it’s slip resistant and drains well. Its problem is its aesthetic appearance. It should be laid over a layer of crushed gravel so the surface water can drain through the asphalt and away. The advantage of the popcorn asphalt is it has the ability to reseal itself in warm weather if the ground freezes and heaves. It can also be used as a base layer under rubber mats or rubber bricks.
6) Concrete (custom colored and/or textured) or concrete pavers: Not a very horse-friendly material to use. It can be scored to give it texture, tinted to give it color and in some cases a brick pattern, but it is nevertheless a very unforgiving material. Horses shoes can slip on it and spook a horse especially when crossing from one material to another. However, this material is great when installed under the interlocking rubber brick or rubber mats.
7) Poured in place non slip surface material: This is a good material (a number of different types and manufacturers available) that can be slip resistant, cushioned to protect from a fall and can be used outdoors. It is often used on playgrounds. Blackburn Architects uses it most often in foaling stalls where a seamless continuous surface is desired.
8) Grass ground cover: Not recommended due to its maintenance needs especially when under cover.
9) Grid mats: Can work if the owner wants to use stone or brick dust or some other type of light screenings but requires periodic maintenance.
10) Brick or stone: Not highly recommended as it is less slip resistant though it can look great, especially if brick dust is used elsewhere such as the driveway in a chip and seal application.
With careful attention to design details, it is possible to retrofit your barn to be healthier for your horses. One important renovation to existing built structures is the addition of skylights and ridge vents to increase light and air flow.
Only a fortunate few horse owners design and build a barn from the ground up. Most buy a property with an existing barn. As the photos illustrate, Blackburn Architects’ client Kevin Plank, the CEO of Under Armour®, bought historic Sagamore Farm in Maryland, and undertook a significant renovation to add light and ventilation to the interior of his historic main barn.
Significant expenditures are not necessary, however. In this discussion, I’m offering simple recommendations for achieving healthier living space for horses starting with an existing barn.
For venting an existing barn roof, I suggest one of two options:
1) Add Dutch doors along the barn sides or
2) Add a vent along the bottom edge of the skylight (or ridge if that works best though I prefer the curb vent for better free air access).
Option 1: Add Dutch doors along the barn sides
This option provides good access for ventilation to each stall and a great method of controlling air flow. An owner has the option of leaving just the upper door open to reduce the flow or open both upper and lower doors to give maximum free area. (Of course, in order to open both doors for full access you’ll need to add an interior mesh panel to keep horse in the stall.) If Dutch doors aren’t possible or within the budget, then I recommend adding low wall vents to bring in air low to the floor (which is good for foals and to vent odors caused by ammonia gases near the floor). The vents should be dampered for air control and screened to keep rodents from getting into stalls.
Additionally, Dutch doors provide an abundance of natural light, which reduces the need for electric lighting in the barn and helps purify the stall flooring, reducing the creation of harmful ammonia gases.
Option 2: Add a vent along the bottom edge of the skylight (or ridge)
This option allows for vertical ventilation of the barn using the Bernoulli Principle and the chimney effect. Though the existing barn may not have the best angle for prevailing breezes or roof slope, it will help nevertheless. I also recommend vents at the top of the wall at the roof eave if they can be added. This permits year-round ventilation above the heads of the horses, but still ventilates the barn vertically using the techniques described above.
There are a variety of methods and materials that can be used to retrofit skylights into an existing roof. At Sagamore Farm, Blackburn Architects’ design replaced the existing shingles with a new metal roof (not necessary; Sagamore’s roof shingles were worn out and metal was chosen as a better long term material). In more typical circumstances where the existing shingles are salvageable, simply remove the shingles along the ridge and cut out the sheathing or sub roofing material, leaving only the roof rafters.
Continuous curbs should be built along the edge of the opening. Although a continuous skylight or curb is not necessary, I find it aesthetically and functionally preferable. A skylight can then be placed on top of the curbs spanning from one side of the aisle to the other. The curb can and should be vented. The size and amount of free area depends on the barn design, size and location. The skylight width does not have to span the full width of the aisle but somewhere between 8 to 12 feet should be adequate.
The skylight can be either glass (costly and should be safety glass) or some form of polycarbonate. Check your local building codes for requirements. I do not recommend clear glazing. Translucent glazing reduces the visibility of dirt and filters light, which better serves the barn interior. It’s best not to let a strong band of sunlight hit a stalled horse for a long period of time. I also recommend painting the interior of the roof and framing members a light color to improve reflectance.
If a continuous skylight is not possible, then individual roof skylights can be installed over the center aisle. However, if the skylights are not high on the roof and are not vented, they may not do much to increase the barn’s vertical ventilation.
If the barn has a loft it may be possible to remove it, leaving specific structural members spanning across the barn to hold the building together and to provide wind shear strength to the barn. If the loft is used for hay storage (which I don’t recommended for health and safety reasons), then it may be possible to remove a portion of the loft over the aisle leaving the loft in place over the stall for storage or the reverse of that (remove the loft over the stall but leave it in place over the aisle).
While these approaches to increasing light and ventilation in existing structures can work wonders, you should always contact a structural engineer before installation of skylights to determine if the barn can take the modifications needed of if some additional structural work needs to be done.