It is a good idea to get the difficult tasks out of the way first, and then move on to an easier job.
Why didn’t I use light weight drywall?
The primary reason is fire resistance.
The drywall we used was fire rated Type X 5/8 inch drywall. It has an advertised fire rating of 1 hour, compared to standard drywall, which has an advertised fire rating of 30 minutes. That said, a publication by the Association of the Wall and Ceiling Industry puts the failure time for regular 5/8 inch drywall at 10 to 15 minutes when exposed to 1850F, whereas a 5/8 inch Type X panel would fail after 45 minutes under the same conditions.
Type X drywall has a denser gypsum core and is reinforced with glass fibers, thus the heavy weight. When exposed to fire, the water bonded in the gypsum core is released in the form of steam, a process called calcination. This phase change absorbs the thermal energy from the fire and thus delays the thermal energy transmission from the flames beyond the drywall.
With the release of the water, the drywall begins to shrink and would start to crumble if it weren’t for the glass fiber reinforcement. The glass fibers buy some extra time before the panel will fail.
Building codes require the use of Type X drywalls for certain applications, but not others. But building codes are not a high bar. They just define the minimum standard a building must meet without being illegal or unsafe. Rather than saving a few bucks and handling lightweight drywall, we thought of Type X drywall throughout the building as cheap insurance.
That isn’t enough to convince you? Well, here is another reason: Because Type X drywall is denser than regular drywall, it has a higher mass which provides better sound absorption. In short, it has some cool features that I wanted to quietly mention.
Even though I was still lugging around 86 pound drywall sheets, the job got a lot easier once I moved from the staircase to the remaining rooms on the 2nd floor.
And this is a perfect point to stop the time lapse. Before I keep going with the drywall installation, we will pause for a minute to talk about another magic material that provides fire protection, sound proofing, and thermal insulation. Stay tuned.