Dear Ms. Hill:

I want to insulate a presently uninsulated metal horse barn. I would like the material to provide reduction of radiant heat, reduce the noise from rain on the roof, and not be a fire hazard or cause health risks to the horses. What is the best type of material to use? I live in Arkansas, where it is hot and humid in the summer and moderately cold in the winter.

I will appreciate any guidance you provide. Thank you.

Rose

Hello Rose,

There are many types of insulation that could work to insulate your barn and they all have their advantages and disadvantages. Most insulation, especially in humid climates, should not be applied directly against the backside of the siding. There needs to be a space for airflow so that moisture does not build up on the siding causing it to rot or rust. In most metal barns the siding and roofing are attached to skip sheathing or girts, 1X4s or 2X4s or other boards spaced 16 to 24" on center and attached perpendicular to the wall and roof framing members. Applying the insulation to the inside of these sheathing boards will provide a space for ventilation between the insulation and steel panels.

If your barn is heated you will need to install a vapor barrier on the inside of the insulation to prevent condensation on the insulation, siding and framing. Here's a clip from our video, Your Horse Barn, that explains about condensation.

Here are some insulation choices for your metal barn.

FIBERGLASS
Fiberglass in puffy rolls or batts is commonly applied between the framing in walls and roofs. The fiberglass is available with a paper vapor barrier and comes in widths that fit between framing that's spaced 16" or 24" apart. The paper face goes to the inside of the room and the edges of the paper are unfolded and stapled over the exposed edge of the studs or joists. Again, don't push the batts tight against the backside of the siding or roof, rather leave a space for air flow to remove moisture.

If you are using the kraft-paper faced fiberglass insulation you don't need another vapor barrier over it. Plain batts require a vapor barrier of 6 mil poly plastic.

Mice and birds love to make nests of fiberglass plus it is unsightly if left exposed. You'll want to cover fiberglass insulation with some sort of rigid paneling to protect it from damage.

RADIANT BARRIER
This insulation resembles foil-covered bubble wrap and come in rolls. The material cuts with scissors or a knife and can be put up between the studs or rafters with a staple gun and/or adhesive. If cut several inched wider than the span between rafters, for example, the insulation can be first stapled to the girts and then folded 90 degrees along the edges and stapled to the rafters.

FOAM BOARD
Panels of rigid poly foam board are generally covered on one or both sides with silver or black foil or with white plastic. The board can be cut with a sharp knife and attached with roofing nails and/or glue to the inside surface of the girts. It can be tricky to get a good fit between the studs and rafters because the barn framing is usually not perfectly parallel. Gaps between the insulation board and the framing can be taped and covered by trim boards. Joints between panels should be taped or sealed according to the manufacutrer's instructions to maintain the integrity of the vapor barrier. The white faced foam board makes an attractive finished surface that will lighten the interior of the barn. Be sure to check the fire rating of foam board because some are flammable and release toxic fumes in a fire.

POLYURATHANE FOAM
Spray foam insulation is sprayed on the inside surface of the roof and siding between the studs and rafters. It immediately expands and dries quickly to make an air tight and sometimes waterproof seal. It provides the best sound dampening of any insulation. Early formulations of spray foam used urea and formadehyde and were somewhat toxic when applied and in fire so the product initially got a bad rap. Modern formulations, however, use safer ingredients (including vegetable oil) and do not burn or release toxic fumes. Spray foam is typically applied by a professional installer but DYI kits are available.

Spray foam is not the cheapest way to go, but it is the quickest and most effective and the one I would recommend for your metal barn. You can learn more about spray foam products and find a contractor near you at SprayFoam.com.

No matter which insulation you choose, it should be covered by a rigid material wherever horses could reach it to keep them from chewing it.

Best of luck and let me know how your insulation project turns out.

Richard Klimesh