What's this stuff?

Jelly, jelly everywhere?

Yes, that is SPF jelly.

Sap. Douglas fir.

Douglas-fir is a resinous wood, with a characteristic sweetish odor… Exudations
of resin on end and side surfaces and pitch pockets are common.

Yep see it in most attics.(looks like basement here)
The unventilated ones seem to have more.

I notice they are using beam jacks,and do not see any fasteners either.

We call them pitch pockets aroud here.

Its just pitch.