Item pages beat trade pages every time. Somebody wanting fitted wardrobes types that, compares pictures and enquires, whereas a page about carpentry services in general reaches somebody with no particular plan.
The small jobs are worth taking. Hanging a door, fixing a sticking window or building one shelf is searched constantly, pays modestly and introduces the household that commissions a staircase two years later.
People use the name of the timber. Oak, walnut and painted poplar attract people who have already decided on a look and a budget, and naming what is worked with reaches them before any comparison begins.
This trade is judged visually. Search brings somebody who then looks at photographs for thirty seconds, so each item page needs its own images rather than a single shared gallery.