“Roughing in” a radiator refers to the installation of radiator piping in a building during the initial construction or renovation stage, before the walls and flooring are finished. This process involves installing the necessary pipes and fittings to be installed in the correct locations. 

When roughing in a radiator, the first step is to determine the location of the radiator in the room. This is typically based on the building plans or the preference of the homeowner. This involves running pipes through the walls or floor to connect the radiator to the heating system.

The size and location of the pipes will depend on the size and type of radiator being installed, as well as the layout of the heating system. It is important to ensure that the pipes are properly installed and securely fastened to prevent leaks, noise and damage.

After the piping is installed, the next step occurs after the renovation is completed. The pipes are then connected to the radiator, and any necessary fittings or valves are installed to regulate the flow of hot water or steam.

Once the radiator is installed, it can be finished to match the surrounding decor. This typically involves installing valves, bleeders and escutcheons in matching finishes.

Roughing in a radiator is a complex process that should be performed by a professional plumber or heating contractor to ensure that it is done correctly and safely.