Comparing the Spanish beamed ceiling with the more familiar French, Flemish, and English examples, we find that the Spanish was almost invariably of pine, and those north of the Pyrenees, of oak.
In the latter the art of joinery and molded sections was carried to a nicety.
Timber lengths were shortened and carefully dovetailed, mortised, and pinned; and so ingeniously were the component parts locked together that the master was free to carve or mold his beams without materially reducing their rigidity.
In the Spanish ceiling, on the contrary, construction remained crude. Beams were simply dimensioned, the transverse members resting on the principals instead of being let in.
When there was paneling between, it was visibly nailed in place instead of being pinned; carved and molded beams were rarely used.
Nevertheless, the whole, when painted, became at once the chief architectonic feature of a Spanish room.
No other built-in accessory in wood competed with it, for the room usually consisted of four flat unbroken walls. Only in Andalusia was the interior enlivened by a wainscot of colored tiles.
When carving was introduced into the beamed ceiling it was confined to the corbel.
It was not the robust carving of northern Europe; but the corbel was made to look, by a minimum of cutting, like a weird head.
Not that the Spaniard was unable to carve the figure; he excelled in it and elsewhere used it almost to excess, but that the whole ceiling tradition remained Moorish, and the Moor never cut the figure in the round. His carving was more likely to take the form of cutting back to a second plane
The Exposed Beam Type:
In its plainest form this type is practically little more than the exposed underside of the floor or roof construction above.
In actual making, it is the simplest of all, consisting of a series of principal beams extending from wall to wall and supporting a secondary tier of smaller transverse members.
The beams may be set either flat or to form a pitch, according to whether there is a floor or roof directly overhead. In large lofty halls the covering often rests on stone arches thrown across the room, an ancient method of which there are Asiatic and early Lombard prototypes.
The medieval flat beamed ceiling was the preferred covering for the Romanesque cloister gallery north as well as south of the Pyrenees. In Spain during the eleventh and twelfth centuries monastic houses, built mostly by French monks, sprang up all over the regions from which the Moor had been driven.
Naturally, none of their primitive wooden cloister ceilings remain, but the most ancient survivors, like that at Santo Domingo de Silos dating from the fifteenth century, give a fair idea of what the earlier ones were like in form.
That the covering of the cloister walk should have passed in time to the patio walk of the castle or palace is natural enough. Here and in domestic work, in general, ceiling-makers varied the detail until they reached a point appreciably distant from cloister simplicity.
In monastic examples master-beams were placed from six to, eight feet on center, and smaller transverse pieces from twelve to fifteen inches apart. This is not an uncommon arrangement in later-day domestic work, but where rooms were wide, master-beams were sometimes omitted altogether and a series of equally stout timbers were placed about twenty-four inches on center.
Where the span was very great, the beam ends rested on projecting corbels often two or three feet in length. This corbel or mensula was frequently carved in the conventional Eastern fashion, and its use tended to give the ceiling a camber, thus correcting the sag so inevitable in old wooden ceilings.
In many examples, monastic and secular, a structural refinement is encountered in the form of a board fill between the small beams of the secondary tier at their point of rest on the master-beams.
This greatly reduces the nakedness of the timbering, by giving the smaller members every appearance of being housed into the principals instead of merely resting on them.
The fill is often inclined outward, a precedent set in early monastic work in order, it would appear, to facilitate reading the legends and escutcheons inscribed thereon; in such instances, however, the wall- or frieze-board between the master-beams is set at a similar angle.
As to the altogether crude method of putting together these coverings, it has already been touched upon in comparing the Spanish beamed ceiling with the Gothic examples of England and northern France.
Besides the painted ceilings, a goodly number of undecorated ones survive. Many are of imposing size with beams hewn from enormous timbers and resting on carved corbels.
An interesting and ancient one may be found in the room under the library in the monastery of Santa Maria de Huerta, between Sigiienza and Calatayud . In several old houses around the cathedral in Barcelona are others whose only decoration is the painted escutcheon on the corbel faces.