Lumber and cement have owned the materials conversation all year, one on sawmill capacity and Canadian duties, the other on low-carbon retrofits and a 50% tariff wave. Look past them and the picture’s just as ugly. Aluminum mill shapes ran up 48.8% year over year in May, and the categories nobody talks about, gypsum and insulation, are resetting again.
The numbers behind the drywall
Aluminum is the eye-catcher. A 48.8% year-over-year jump in the producer price index for mill shapes shows up fast in curtain wall, storefront, railings, and trim. Earlier in the year one major fabricator pushed a 15% increase across its performance metals line. Gypsum’s quieter but no calmer: after a steady start to 2026, manufacturer notices are landing across wallboard, and quote sheets have reset through June and July with more volatility expected on supply-side concerns.
Insulation tells a similar story. Prices dipped about 1.4% in the first quarter, then kept climbing, and the category now sits near $0.64 a square foot, up roughly 19% from a year ago. Summer demand usually pushes another increase into the third quarter. Stack it up and inputs to new nonresidential construction rose 8.4% year over year in May, a number that doesn’t care which material you blame.
What it means for a bid
Here’s the trap. When lumber and cement dominate the trade press, an estimator can convince a client that “materials” are stabilizing because the two loudest indices cooled off. They aren’t the whole building. A 270-unit apartment job like The Gateway in Orlando or a 19-story office tower buys aluminum, gypsum, and insulation by the truckload, and those lines are moving the wrong way regardless of what a lumber futures chart does.
The Associated General Contractors has spent the year warning that headline input numbers hide as much as they reveal, and this is the case in point. A single blended escalation factor is a fiction when aluminum’s up 49% and something else is flat. Estimators bidding 2027 work are better off pricing the volatile categories separately, holding escalation allowances by material rather than by a lump index, and writing shorter price-lock windows into subcontracts. The clients who get burned this cycle will be the ones who heard “lumber’s fine” and assumed the rest of the invoice was too.