This Exeter roof is remarkable, as much for its details of similarity to that of Westminster Hall, as for its many points of variation. The latter has now to be considered to bring this chapter to its conclusion.
The roof of Westminster Hall, drawings of which are given in Figs. 90 and 91, among other claims to distinction, is easily the largest and the most elaborate example of its kind existing. The Hall itself was built for William Rufus, and at Whitsuntide, in the year 1099, he held Court in the Palace of Westminster, as it was then styled.
Fig. 87. The Law Library, Exeter, N.E. End.
We have no exact knowledge of the original roof of the Hall, but it is conjectured that it was in double-aisled form, with wooden posts to the floor, in the manner of York Guild Hall. Considering the standard of roofing science at the date when the Hall was built, this form of construction is the only one which can be imagined for a vast hall, 238 feet in length by 68 feet in span.
It was in 1394, in the reign of Richard II, that it was decided to renew the roof, and in that year, John Godmeston, Clerk, is appointed " to cause the Great Hall in the Palace of Westminster to be repaired." Hugh Herland, the King's Master Carpenter, was entrusted with the control of the work, to enroll men of the various trades from all parts of England, excepting in the fee of the Church, and to " arrest and imprison any contrariants."1
Fig. 88. The Roof Of The Exeter Law Library. - View looking up at a Bay.
Fig. 89. The Roof Of The Exeter Law Library. - Detail of a Truss. 97
The timbers of the Hall roof are of Sussex oak, Quercus pedunculata, chiefly from the King's forest or wood of Pettelwode. The assertion that chestnut was used for the timbering could only have been made by those who had either not inspected the roof at close quarters, or had been deceived by the surface colour or bloom which the timbers now exhibit, the result of a superficial surface rot.
Elevations of a principal truss, and a bay are illustrated in Figs. 90 and 91, together with a plan of the Hall. A general view is also given in the illustration facing this page. It is impossible, here, to give more than a brief description of this wonderful roof. To begin with, it was obviously impossible to obtain timbers of sufficient length to act as main tie-beams or principal rafters. The roof, therefore, begins with an upper triangulated framed structure, formed by the main and upper collar beams, the ridge with its bracing, the collar-post and the compound main and upper purlins, and the crown-post supporting the heavy ridge, together with the principal and common rafters down to main purlin level. This upper structure is carried on triangulated cantilevers, formed by the hammer-posts, the hammer-beams, the wall-posts with their arch-braces, the lower principal rafters and the compound wall-plate. To tie the whole roof together, the great curved rib or arch-brace is introduced, springing from the stone corbels at the feet of the wall-posts and rising to its apex at the centre of the main collar, intersecting both the hammer-beam and the hammer-post on its way.
Those who have read and understood the construction principles of the various roofs which have already been described, will see that in Westminster Hall several types have been compounded into the one. Sections of the various roof members are given here, necessarily to a minute scale. The following list of sizes and scantlings
1 Extract. 1394 Jan. 21.
Patent Rolls. 17 Rich. II. M. 3.
Appointment of John Godmeston clerk to cause the great Hall to be repaired, taking the necessary masons, carpenters and labourers wherefor whenever found except in the fee of the church, with power to arrest and imprison contrariants, until further order and also to take stone, timber, tiles and other materials for the same at the King's charges and to sell branches, bark and other remnants of trees provided for the said hall, as well as the old timber from it and from an old bridge near the palace by view and testimony of the King's controller of the said works for the time being accounting for the moneys so received and receiving in that office wages and fees at the discretion of the Treasurer of England.
By Bill of Treasurer.
Westminster Hall. - An eleventh-century Hall with a late fourteenth-century Roof.
Fig. 90. Westminster Hall Roof. Sectional View Ok A Principal Showing The Great Arch-Rib. - The view of the Principal, Bay and Details from a drawing by H.M. Office of Works, prepared may be of service in giving some idea of the gigantic dimensions of the timbers in this wonderful roof
Fig. 91. Westminster Hall. View Of A Bay And Plan Of Hall, From An Original Measured And Detailed Drawing By Ernest R. Gribble And W. Rennie, 1910.<table frame="box" rules="all" border="0">
(at abutment 38 1/2")
Collar-beam (of two members)
Lower principal rafter .
Upper principal rafter .
9" X 12"
15' 0" to 20' 0"
Lamination of rib .
8" x 12"
Inner bracing-rib ....
14' 3" maximum
Wall-plate (compound) .
15" x 8"
15' 0" to 18' 0"
Upper and lower purlins
9" x 16 1/2"
Main purlins (consisting of 4 members) : -
Top inner ....
Top outer ....
Laminating purlin .
22" x 9"
I4 1/2" x 9"
Common rafters (laid flat)
. 8" x 6"
26' 0" to 32' 0"
24 1/2" x 16"
. 5" thick
14" X 11"
Some idea of the enormous weight of the timber in this roof, which is supported almost entirely from the wall-heads, may be gathered from the fact that a single hammer-post measuring 38 1/2 ins. by 25 ins. in section at abutment, with a length of 21 ft. 6 ins., weighs three and a half tons. This sectional measurement is also not the maximum one. Actually the hammer-post must have been fashioned from a trunk nearly 4 ft. in diameter.
With Westminster Hall, this review of the English timber roof can be fittingly concluded. Here, almost in the heart of London, we have the greatest triumph of mediaeval carpentry which England has ever possessed, a testimony alike to the fourteenth-century woodworker and to the qualities of English oak.