Abstract: An inside-out heating method provides efficient and economical heating of wet cement during the curing phase in building structures. Hollow building blocks and their cement joints may be heated by applying forced hot air injected at the base of the wall. The hot air rises up through the wall and out of the open end of the top course of block by the chimney effect of the hot air rising through the ducting created by the aligned vertical passageways in the hollow blocks. The hot air is distributed through the wall by a manifold and injection tubes which provide air ducting from a heat source, such as a forced air propane heater. Temporary holes are broken through a low level course of block to receive the hot air injection tubes. After the cement has fully dried, the injection tubes are removed and the temporary holes are filled in with cement.