http://www.maderas-techos-tirantes-machimbres.com/maderas-pa...

Los listones y alfajias para techos cumplen variadas funciones y pueden cortarse en distintas medidas. Las mas comunes son:

* 1/2" x 1" , yesero para sujetar el ruberoid
* 1" x 2" para clavar la teja
* 1" y 1/2" x 2" para clavar la teja
* 2" x 2" para clavar las chapas
* 2" x 3" para clavar las chapas
* 1" x 1" para clavar el liston de la teja colonial
* 1" x 3" para clavar la teja colonial
* 3/4" x 3" para clavar la teja colonial
* 1/2" x 2" para colocación de machimbres en pared
* 1/2" x 3" para colocación de Corlok o Decoplay
* "1 x 2" para colocación de Durlock

Estos listones o alfajías pueden ser de pino eliottis, pino paraná o eucaliptus saligna.

Based on the dimensions given, "batten" (or lathe) is far more suitable than crossbeam. There are also dozens of dictionaries supporting this translation.

http://en.wikipedia.org/wiki/Battens
"Roofing battens

Battens are used to provide the fixing point for roofing sheet or roof tiles. The orientation and spacing of the battens depends on the type of roof. Battens may be oriented at right angles to the trusses or rafters of a roof, like purlins. They may be parallel to the slope of the roof, as on a batten seam roof, where the battens cover seams in the roofing material and are themselves covered by metal caps. Some roofs may use a grid of battens in both directions, known as a counter-batten system."