Hipped Roofs.—As a general rule, however, it is found expedient to hip back the roof rather than carry it up in a tall gable, partly because cob-building at a great height above the ground in short and diminishing layers is a somewhat tedious process, partly because a hipped roof with good eaves is very welcome for the protection that its projection affords the walling.
WALL COPINGS.
Masonry and Carpentry.—The bonding of cob to stone and brick is sometimes liable to leave an open joint that will require filling when the cob dries and shrinks. Many of the chimneys in old cob houses are of brick or stone, and brick and stone jambs are sometimes to be seen in cob walls, but they are probably by way of repairs to damaged corners. It is considered better to have cob all round, so ensuring the uniform settlement of the building.
The timber built into old cob does not seem to decay. The walls are usually so dry, especially when plastered, that the wood is well preserved. The straw in the interior of old cob walls is often as bright as when put in. The straw in cob performs a similar function to hair in plaster. Heather has sometimes been used instead of straw with good results.
LINTEL-BEARING CROSS-PIECE
The old practice was for beams, wall plates, joists, etc., to be just bedded on the cob, and for the cob to be filled in between the joists. In new work, particularly when the use of imperfectly seasoned timber is unavoidable, it would be wise to take the usual precautions as to the proper ventilation of all “built in” woodwork—especially the ends of joists and so forth. Roofs must of course be tied and exercise no thrust on walls. The roof plates are sometimes tied down by galvanised iron wire.
Door and window-frames are also fixed to wood blocks built into the jambs and to the wood lintels above. The frames are sometimes near the outer face of wall, sometimes near the inner-face. Where the door-frames are on the interior face of a 2 ft. thick wall, a convenient porch results.
Other joinery is fixed to wood pins driven into the cob where required.