Hey there, time traveller!
This article was published 21/9/2012 (1616 days ago), so information in it may no longer be current.
QUESTION: Should I be adjusting my teleposts after discovering horizontal cracks in the drywall? One is in the ceiling opposite the bathroom in the hall, and the other in the side wall of the basement stairs. Shona Treleaven
ANSWER: I am answering your question at this time due to the rash of calls and emails I have received in the past couple of months about your issue. With the dry summer weather, many homeowners are experiencing unusual cracking and movement in their walls and other areas of their home. While this may be a somewhat rare occurrence caused by unusually dry soil conditions, it does happen to many homes and I will address the issue accordingly.
Cracks in plaster or drywall in an older home are a very common occurrence in our area due to our expansive clay soils that the homes are built on. This soil will expand and contract with changes in moisture content, which is compounded by the wide temperature swings from summer to winter. Because of this, many homes built on typical concrete footings will move regularly. This settlement is often more pronounced in the first couple of decades after a home is completed, but can happen later due to changing conditions in and around the building. If you have small, hairline cracks around windows and doors and in some ceilings, telepost adjustment is likely the solution. If you have larger cracks, running diagonally or horizontally along walls or between walls and ceilings, you may have a bigger problem.
The reason that teleposts are adjustable is to allow for minor modifications to the floor structure to accommodate typical house movement. Just as there are footings under foundation walls, there are similar sized ones under the main beams and teleposts. Even though they may be similar in size and thickness, interior footings may have different loads than underneath the heavy foundation walls. As footings in a home settle around the perimeter they may not move the same amount in the middle. Also, the soil outside the perimeter of the structure is considerably more susceptible to changes due to moisture and temperature fluctuations. For these reasons, homes often settle considerably more around the perimeter than in the middle.
The size and direction of the cracks are not the only indicator of the need for adjustment of teleposts in your basement. Most homeowners first start wondering about this subject when they notice bumps in their floors. These may be quite subtle or more noticeable depending on location. If the teleposts are located underneath interior walls, the bumps may go undetected. If these metal columns are located below the middle of a hallway or floor, especially if the flooring is patterned, they may be more noticeable. Slow, careful adjustment of the teleposts is normally the solution if the bumps are not overly large.
While floor movement may or may not be visible to the untrained eye, door movement often is. If interior doors begin to rub on the floor or the jamb, it is another sign that the floor is moving unevenly. Instead of cutting or planing the doors, lowering or raising appropriate teleposts should improve the operation. With a little more intensive investigation, the angle and direction of interior door movement can assist in determining which way the floor is moving. Also, these can be used to help decide which teleposts need the most adjustment relative to others. Once a few partial rotations are completed, the doors should stop rubbing as the frames are re-squared. If the door operation does not improve, or becomes worse, the adjustments are being done improperly or too quickly.
While it may be relatively easy to measure and adjust teleposts in an unfinished basement, this can be very difficult in many homes with elaborate rec-rooms. It may be difficult to locate and measure the columns, main beams and floor joists, especially if the ceilings are finished. Many homeowners enclose the teleposts completely, hiding even the adjustable threading near the top. To access these, and do measurements to determine the amount of adjustment required, portions of walls and ceilings may have to be removed. To compound this, many basement partition walls may be built without adequate room between the top plate and the floor joists. If there is not a substantial, purposeful space between the top or bottom of these interior walls and the joists or basement floor slab, lowering teleposts may not be possible. These walls can actually cause additional movement, bumps, and problems as the house settles, improperly holding up portions of the floor. These partition walls and coverings may have to be cut down prior to any telepost modifications.
To respond to your main question, yes, adjustment of your teleposts is almost certainly required, but that may not be the only issue you face. I would strongly recommend consulting a Registered Home Inspector, Professional structural engineer, or very experienced general contractor to look at the situation before touching any teleposts. There may be more going on than minor settlement and you may have to make modifications or repairs to your foundation or basement walls before adjusting these important structural components.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the president of the Canadian Association of Home & Property Inspectors - Manitoba (www.cahpi.mb.ca). Questions can be e-mailed to the address below. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca.