Surveying Your Old Barn

By Charles Whitney

Below is a checklist for evaluating the soundness of a barn. Use this as a resource for identifying maintenance problems early, before they become expensive repairs.

  • Study the barn from a distance. Check the ridgeline — is it straight? Does it sag? If so, it may need repairs. Move closer to the barn and look up the flat side of the roof. Does it sag, indicating that the rafters may be bowed? Check the roof system further from the inside.

  • Carefully check the exterior sides and corners of the structure to see if they are plumb. A plumb bob or weighted string will help site the corners and sides to indicate if the frame is vertical.

  • Notice the gutters. They are one of the most important parts of any building. Their function is to direct the roof water away from the foundation and siding. If the gutters are missing, rusted out or damaged, they should be quickly replaced.

  • Siding protects the structural members. Replace any missing or broken boards. What is the condition of the paint? While you are surveying the siding, take note of the windows, doors and louvers. These should be intact and closed to keep weather and birds out of the barn.

  • Now take a look inside. If you have a bank barn, start at the doors on the driveway and fully open them to let in light. Notice the floor and sill at the bottom of the doorway. Seventy percent of the bank barns have serious decay at the threshold. The wooden sill may be gone and the floor joists that are intended to rest on the stonewall may be rotted off at their ends.

    This is a dangerous situation. The missing sill should be replaced and the rotted joists extended to meet it. Sometimes a concrete apron is poured instead of replacing the timber sill. If concrete is chosen, a crossbeam and jack posts can be used to support the floor joists.

  • Stand inside the doorway and study the entire barn frame from this point. Look for signs of water leakage. Black stains indicate long-term leaks that may have caused serious damage; white stains indicate more recent leaks. Examine the location of these stains to determine the extent of rot. Rotted timbers and braces should be professionally replaced. A do-it-yourself project could accept 2x materials scabbed onto existing timbers to provide strength.

  • Examine the mow and driveway floors. Are they solid? Be sure they are safe for the anticipated loads.

  • Carefully examine the base of all sidewall posts for decay close to the ground. Check the roof from the outside. If you see a riffle in the shingles over the purlin, it is a sign the sidewall posts have bottom decay and that the sidewalls are settling.

  • Check the roof for holes from a dark interior. The bright sunlight will show every nail hole. A good roof is essential to protect the structural system and if kept dry, a timber frame barn will last for centuries.

  • Go to the basement. Notice if you find excessive dampness that will damage a wooden frame. Dampness can be reduced to acceptable levels by proper ventilation. Check the supporting posts to be sure they stand on solid footers. Check the underside of the mow floor joists for decay and powder post beetles.

    Powder post beetles are the rascals that make the tiny holes in timbers. They came into the barn with the original timbers. Unless you find fresh white powder or frass beneath the holes, there is nothing to be worried about. If you do find frass, there is ongoing powder post beetle activity, but this is easy to eliminate by spraying with turpentine. No need for expensive chemicals or treatments.

  • While in the basement check for signs of water. Dampness may be due to foundation water seepage, especially on the hill side of a bank barn.

  • The foundation should be carefully checked. Is it solid? Does it have cracks? Are there small sections that have fallen out? Special notice should be made of the wall along the hill side. Shine a flashlight along the wall to determine if there is an inward curve. A slight convex wall indicates that seasons of freezing have forced the wall inward to the basement. This may be serious enough to require rebuilding the wall.

  • Finally, you can do an overall inspection of the barn and its surrounding terrain. Is the ground properly graded to drain water away from the barn? Do the downspouts carry water away from the foundation?

  • Attached sheds are often a detriment to the principal structure. The usual problem is the roof flashing between the shed and barn. If water is seeping between the two structures, both sections are going to eventually have decay.

  • The above comments are based on surveying a bank barn. If your barn is a grade barn without a basement check the foundation. Many grade barns were built with large stones placed at the corners and under the sidewall posts. Sometimes there was a sill to help support the barn walls. Often the stones have settled and the posts have come in contact with the moist earth. Old stone foundations can be replaced by jacking the barn, and replacing the stones with a block wall laid on a footer below the frost line.

This article is reprinted with permission from The Barn Consultant, which is published six times annually by Charles Whitney, 36 Woodberry Drive, Mt. Vernon, OH 43050, Subscription is $10 per year.