“Settling”: The Big Lie
A new home or an addition is about 3 or 4 months into its occupancy. Cracks Happen. The builder and/or architect/designer are called, and either or both responds with a one word blanket excuse: “Settling.”
“Settling” is offered up by design/build professionals as a universal construction mulligan, a “get out of jail free” card. “Settling” has become the universal absolvent for building incompetence.
It’s as if “Settling” is an act of God, like a hurricane or -15F. “Settling” in builder terms means that the new construction naturally seeks its own level, that gravity is unevenly applied and some parts of the construction do not move and others do: the canard is that these materials have a mind of their own, and their movement is not controllable or preventable. In short, “Settling Happens.”
In reality it is uneven movement that creates cracks, and several factors cause that unsightly and potentially dangerous resolution. Most all of these resolutions are benign, and in a perfect world engineering, design and builder craftsmanship would prevent every last one of them: but some cracking occurs in many new and remodeled/expanded homes.
Here are the reasons:
1) Inadequate foundations for the subsoil the foundation was set upon: either the subsoil is wet, filled organic material (like dead tree roots) or when the foundation is set on new soil that soil is not compacted prior to construction, so once loaded up with the full weight of occupancy the soil compresses and the part that is inadequately supported moves: one part of the home succumbing to gravity while the adequately supported part stays where it is: and cracks happen.
But that cracking is the tip of the structural accommodation iceberg: look at the foundation walls: diagonal cracking where the split wall planes are not the same aligned means things are moving, and not finding a place of repose: “Settling” infers finding a resting place of ultimate stability: that’s often not true.
A corollary to this are places where the bottom of your foundation is set too high to be at a level thats below frost. All soil has moisture. All water expands when frozen. If the foundation rests on soil that is close enough to freezing temperatures that the ground under it freezes, the foundation is pushed up, then drops back down at thawing, and the process repeats, over and over again, and cracks happen: there is no “settling”.
2) Inadequate or poorly executed framing can have a column or two cut a little short with nails or sheet rock carrying weight that should be directly supported by the columns or walls. Or a roof rafter or floor joist is similarly misplaced, creating a gap at the wall or beam under it: loading happens: cracks result as the roof/floor/wall lowers to meet a point of support.
3) Even code-compliant, well designed and built homes move when extraordinary loading is applied- especially dynamic loading involving movement or wind – vibration causes cracks as floors, walls and roofs flex. Not dangerous, or the result of incompetence, but by saving a little money in just meeting the minimum stiffness you may end up regretting a little structural overkill.
4) Most cracks happen for reasons that have nothing to do with poor craftsmanship or bad soils. Most happen, believe it or not, because of a loss of moisture in some, but not all, of what is used to construct most home’s structure.
“Engineered wood” is structural framing made of plywood, wood chips compressed with glue or a combination of processed wood and natural wood. These products do not move very much when the humidity changes. Conversely framing lumber is filled with water, especially pressure-treated wood -and the density of the lumber without water has been greatly reduced in the last 30 years as growing techniques have made trees grow faster and faster, and thus have less density, wider graining, and thus graining than moves more than the good old days when trees were grown naturally.
Where homes are heated or cooled without humidification the moisture which started out at 19% for kiln-dried framing lumber can be cut in half, while the small amount of moisture in “Engineered Wood” stays the same – or if steel is employed those parts are not effected by dry air. When one part of an assembly moves with humidity and another doesn’t’t cracks happen, but “Settling” doesn’t.
5) Similarly when new structure is set next to old, the old has already lost its moisture content, stabilized, and its foundation has resolved any inadequacies it might have had, and unless care is taken to provide overlap and connection and unless correct material selection is employed (those engineered wood products are great next to an old, dry wood structure) cracks happen as the new parts move next to the old stable parts.
So the vast preponderance of “Settling” is due to “Shrinkage”.
The truth is that some cracking is inevitable as the thousands of connections between different structural members are subjected to humidity and temperature rise and fall. But careful building and good design can minimize those conditions and they are small enough that a flexible caulk can be applied, reapplied and applied again that ultimately makes cracks a small problem, with no long term consequences.
So when a builder or architect pleads “Settling” do not settle for that answer, its a whitewash and a wish-away. We all want mulligans, rationalizations and CYA to make problems disappear – but you have a life sentence in your home: do not settle for “settling”.