Drywall is older than you may think, and was invented in 1916 by the U.S Gypsum Company and first sold as tiles rather than 4X8 or 4X10 boards. Drywall took a while to catch on with builders as they were reluctant to try anything new, especially when plaster was considered the way to go back in the day. However, once the building boom of the 40’s took hold, contractors soon realized that drywall greatly decreased the installation time for wall and ceiling coverings and could provide both a smooth finish or a rough textured look. Plaster was on the way out; in fact drywall got it’s name because it could be installed without the use of water, unlike it’s predecessor.
Drywall is made from Gypsum and other additives which create a paste that is covered on both sides with manila paper. These sheets are then passed through an oven that heats the material to over 500 degrees. This dries out the paste and prepares the boards for cutting.
New developments in drywall include eco-friendly products. One of the big manufactures is right in our own backyard, Serious Materials in San Jose.
Drywall is surprisingly fire resistant as well. Just watch a video of a drywall fire test and you will see just how effective it is. Drywall will buy you and your family precious minutes in a house fire and allow you time to get out of the home.
There are few things more concerning to a home buyer than the presence of cracks in the wall or ceiling drywall. Look closely and you will see some kind of cracking in most homes. Hairline cracking is pretty common, and usually not much to be concerned with, especially in older homes. Hairline cracks usually are the result of common home settlement over the years, and can be easily patched with spackle and paint. Many homes continue to settle slightly through the years. Perhaps you have been sitting in your living room reading quietly when you hear a small but sharp “crack” sound, which is common as framing members settle.
Newly constructed homes will often develop a few cracks in the first year or two, and most of them will be diagonal cracks originating from the corners of the doors or windows or at the areas where the walls meet the ceilings. Corners are typically a weak spot in wall framing. These cracks are usually again the result of foundation settlement that many newly constructed homes experience in the first year or two. New homes can also experience hairline cracking as wet framing lumber continues to dry, which causes the studs, joists and rafters to twist or bow slightly. Major track builders expect to get a number of calls about these cracks from worried homeowners in the first year or two after construction. I trekked down to Morgan Hill for an inspection last year on a newly built single family residence. The buyers were especially concerned about a diagonal crack coming of the corner of a window in the dining room. The crack was a bit larger than hairline, but showed no displacement. My response was to patch and monitor the crack, as new construction cracking should start to stabilize within the first few years following construction. Should cracking continue, the new owners are covered for 10 years (for structural defects) under the state’s Right to Repair Act, and should contact the builder for evaluation and repairs as needed.
Straight line cracks that follow the edge of the drywall panels are typically caused by installation errors. These include poor support (perhaps too few screws, improper joint finishing or failure to provide for seasonal swings in temperature or moisture. This final cause is probably less common in the temperate Bay Area as it would be in areas with more extreme weather swings. Homes in Tahoe that are vacant through much of the year will show cracking due to the extremes in temperature not experienced by homes in the area that are consistently temperature controlled. Your home is actually somewhat dynamic, and moves and breathes with daily and yearly temperature swings.
When is drywall cracking serious? Rapidly appearing cracks that change in shape or size within a year are almost always a concern and can mean structural movement.
The same is usually true with jagged cracks and cracks that are over 1/8 of an inch in width. This kind of drywall cracking is often accompanied by doors that don’t close properly due to the door frame no longer being square because the house is moving. I saw that situation in San Jose last week with the back of a home that was rapidly settling. If you suspect an out of square door frame, run your hand along the top of the door. You may feel roughness that can indicate that the door has been shaved to allow it to close in the door frame. These issues can be caused by ill-prepared soil that does not support the foundation, failure of the foundation itself, or termite damage to the support framing. Repairs can be costly.
Since some drywall cracks may indicate serious structural issues, if in doubt, it is money wisely spent to hire a qualified structural engineer for further evaluation.
See you next time!