Going slow, steady crucial when adjusting teleposts

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This article was published 26/05/2002 (8525 days ago), so information in it may no longer be current.

Question — Over the past few months we have noticed the drywall in our home has cracked above certain doors and other areas. The cracks seem to have occurred on the main floor over the central beam that runs the length of the basement. This beam is supported by three adjustable teleposts.

I have been told that adjusting the teleposts will eliminate this cracking. I would think that this is a somewhat intricate type of adjustment. Is there a professional who can be hired to this?

–Keith Patterson, e-mail.

Answer — Cracks in drywall over windows and doorways are quite common and are normally due to seasonal movement in the basement floor slab and footings. The expansive clay soil underneath the basement floor will swell and shrink with seasonal fluctuations in temperature and moisture content of the soil. The soil may push up on footings below the floor slab when the soil thaws in the spring and may recede during dry periods in the late summer and fall. This movement is the reason that steel teleposts are installed, with adjustable screw mechanisms, below main beams and other floor structural components.

Much of this movement occurs in the first 10 to 15 years after construction of a home, due to the initial disruption of the soil, but it may occur anytime. Homes are built with an integral drainage system near the footing, commonly referred to as “weeping tile”, to reduce the fluctuations in soil moisture levels. Much of the snow runoff and rainwater are channelled to the municipal storm sewer in older homes through this system. In newer homes, the water is drained into a sump pit and is pumped back outside the home to “recycle” it. Once the soil moisture level drops, the weeping tiles stop collecting water and this process stops until the next rain.

Adjustment of teleposts may be relatively simple or quite complex depending on the design of the home and access to main beams for measurements. In houses with standard rectangular foundations and one exposed main beam, telepost adjustment may be manageable by the homeowner. In houses with unusual foundation designs, multiple floor levels and beams, or finished basement ceilings, professional evaluation and adjustment are likely required. A licensed structural engineer or a reputable foundation or general contractor should be consulted.

From his brief description, it appears that the main beam design in Mr. Patterson’s home is the simpler variety and may be straightened with minimal evaluation. Homeowners should not attempt to “level” the main beam, but only to minimize unevenness over the footings and straighten it as much as possible. A beam may be considerably lower at one end relative to the other, due to settlement of the home. A very tight string suspended below the beam, with spacers at either end, will give an idea of the amount of lowering or raising needed for each individual telepost. A water or electronic level may also be used to determine the height of the beam at either end and establish approximate midpoint levels, where the teleposts are.

Whichever method is used for measurement of existing beam location, care must be taken when adjustments commence. Very slow adjustments will minimize additional cracking of the walls that may occur if the process is too rapid. An adjustment of no more than a quarter turn of the telepost screw head every two to three weeks is suggested. Due to this slow rate of remedial action, several months may be required to achieve the desired end position. The cracks in Mr. Patterson’s home may be minimized after telepost adjustment, but may also bulge or new ones open up due to patching of previous cracks. Plans for this type of maintenance should be done before painting interior walls, and a period of settlement should be allowed before patching the cracks. Some areas may have to be secured with new drywall screws or have popped fasteners tightened before wall-finishing.

Choice of a contractor to supervise or complete telepost adjustment may be difficult, due to differing opinions on exact method and frequency. Avoid contractors who suggest a “one-shot” adjustment that will straighten the beam in one trip. This may cause excess cracking in the walls and new squeaks in floorboards as well as sticking doors and windows. Slow and steady wins the race with respect to telepost adjustment.

Ari Marantz is owner/inspector of Trained Eye Home Inspection Ltd. and is the P. R. Rep. for the Canadian Association of Home Inspectors- Manitoba (www.cahi.mb.ca). Questions can be e-mailed or sent to: Ask The Inspector, P. O. Box 69021, #110-2025 Corydon Ave., Winnipeg, MB. R3P 2G9. Ari can be reached at (204) 291-5358.

trainedeye@iname.com