Search Website Design and Content © by Eric Krause, Krause House Info-Research Solutions (© 1996)
      All Images © Parks Canada Except Where Noted Otherwise
Report/Rapport © Parks Canada / Parcs Canada  --- Report Assembly/Rapport de l'assemblée © Krause House Info-Research Solutions

Researching the Fortress of Louisbourg National Historic Site of Canada
  Recherche sur la Forteresse-de-Louisbourg Lieu historique national du Canada

DOMESTIC BUILDING CONSTRUCTION 
AT THE FORTRESS OF LOUISBOURG, 1713 - 1758

By

Eric Krause

1996 Draft Report

(Fortress of Louisbourg
Report Number H G 10)

CHAPTER FOURTEEN

FLOORS AND CEILINGS -
JOISTS

Joists were large by today's standards. Seven by 8 and 8 by 9 pouces were common, except in less traveled areas like attics, where sizes were about one-half the above. Their overall size, with their depth being the greater dimension, encouraged wider spacing between joists than practiced today. A distance of 3 pieds, the one most often mentioned, was perhaps routine.

The finish on joists varied. They were either carefully hand-hewn with well-defined, sharp edges, or they were further planed and given softer edges, like a quarter-round molding. Otherwise they might be far more roughly hewn, if destined for a relatively crude construction, or half-squared off, or simply split from the log.

A sleeper - a joist which rested directly on leveled ground - was susceptible to rot. A precaution which the contractor for the Royal Battery was to have implemented was the placing of charcoal clinkers (gravel could be used as well) between each sleeper. The idea was that the charcoal rather than the wood would absorb most of the moisture.

Far better than sleepers though, and quite easily achieved in charpente and masonry constructions, was the elevation of floor joists above the ground. One method, in charpente construction, was to dovetail (or tenon, though a tenon might break) a joist into the frame. Another was to rest the joists on a ledge, making use of the foundation (and, at the same time creating a ventilated crawl space).

A ledge was not, however, every builder's preference, even when one was available. Neither was an open crawl space and, indeed, one contract, that for a Block C house, stipulating a 2 1/2 pieds high foundation, specifically directed that the crawl space be filled in level to the wooden ground floor above.

Large wooden beams sealed in a masonry wall, thereby weakening the wall, was another way to support joists. François Vail ridiculed this method and suggested alternate techniques: stone ledges at each storey of a masonry structure; or 6 pouce deep joist sockets into which joists could be thrust, sealed in mortar and secured by nailing on both sides or supporting with one pouce thick iron S-hooks; or wall plates at the summit of walls for carrying joists and roofing members. Iron stirrups and flat iron bands were also useful devices for securing joists.

Joists which normally span a building's shortest distance, usually the width, sometimes required mid-support for safety's sake. Such a situation usually arise in masonry buildings which tended to be on the wide side. The traditional solution was a mur de refens, an interior bearing wall that might also support roofing members, or, if of masonry, a chimney stack.

Anyone expecting the weight of a floor to exceed normal limits would have chosen shoring, a proven technique for added joist support. In 1744, for example, carpenters fashioned large piquets for supporting a floor in the Block One magasin-general. Also receiving help were floors in a Port La Joie magasin des vivres, in the King's Bastion pavilion and in the treasurer's office in the commissaire-ordonnateur's Block 2 residence. In the last case the props were of oak. In general, props were simply nailed at each joist with large nails.

Finally, a group of experts agreed that a certain storehouse owner should have foreseen that ten tons of merchandise in an attic required shoring, notwithstanding the possibility that the joists may have been rotten. As it was, the joists had sagged in the middle and, pulling away from the wall plate, had given way. Everything had then crashed down.