Recently bought a home that came with a double detached garage. The garage is older, perhaps from the 70s? It uses what looks like an early adoption of a truss framed roof. The trusses look like they might have been built on-site, using a variation of queen-post (fan?).
The previous owner mistakenly decided to store various items across the trusses, causing sag. The sag is visible from on the apex of the roof from end-to-end (bowed), and between the ends of individual trusses (sagging in the middle).
When the previous owner moved out, they removed the junk, and I can see that the problem has corrected itself fairly substantially. I am concerned that if I just strap up drywall, that I will be applying more load that what the trusses were meant for, inevitably making the problem of sagging and distortion worse.
What should I do to prevent this from getting worse?
How can I introduce sufficient strength into the trusses and related structure to allow for drywall and insulation to be added safely?
- Jack up the centre of the trusses, then reinforce each bottom chord with a 2x4 that spans the entire width of the garage.
- Jack up the centre, reinforce (as above), and also replace any wood strapping with steel mending plates, hurricane ties, etc.)
- Leave it as is, strap up drywall, pray to the gods.