For years, the use of lightweight building products in residential construction has been on the rise. As builders want to increase their productivity through quicker building times and reduced costs on materials and labor, the market has been flooded with lightweight materials.
We can find lightweight trusses in the roof and in floor joists or I-beams. The I-beams are used on any level of flooring to provide a wider span for the open-concept look.
They offer a higher strength ratio than the traditional solid wooden lumber. The same is true for the roof joists where wider spans are achieved, which reduces the amount of material needed.
New stairs
I recently received an advertisement for a new product called the i-stair. This new product replaces the traditional construction method for stairs in residential buildings. It is reasonable to expect similar products either are or will be on the market.
With the introduction of this new product, we now have one more domino lining up. The dominos that are lining up are not the result of any firefighter or fire department actions — they are the result of the construction-industry actions. There will be a collapse potential not just in the roof or on the floor, but also on the stairs.
There are some commonalities that we can focus on in an effort to educate ourselves. One common point is the use of OSB, or oriented strand board, as the main building component.
OSB is used for lightweight floor joists as it replaces the 2x10 or 2x12 piece of lumber. It is much thinner than wooden lumber. It is made primarily out of wood chips and held together with glue. Compressed and heated to a high temperature, the wood chips become a thin piece of wood. This is the main ingredient in the i-stair.
As you can see in the picture, the tread and riser are constructed out of OSB. The failure rate of the stair will be increased as OSB breaks down and fails at a quicker rate that traditional wood lumber.
Gusset plates
Another common point is the gusset plate. Gusset plates are used to hold together roof joists members. They are typically square and have many fingers that are pressed into the wood, replacing nails. The pressed depths of the fingers are only about a ¼ inch and are not always consistent.
We can see the use of gusset plates on the i-stair on the underside of the tread and the riser. Designed to provide more strength and support, gusset plates are known to peel away from the wood as they are heated. Once they are separated from the wood member, the system fails.
Be on the lookout for these new products that are being used in residential buildings. Even though it is a new product, they can be found in retrofit projects, renovations as well as new construction.
