Perth's Lade

The Roof at Hamilton's Land, Linlithgow 

The National Trust for Scotland commissioned Alder Archaeology to carry out a Historic Building Recording on the roof at 42-44 High Street, Linlithgow which is part of the 16th century group of buildings known as Hamilton's Land.   The requirement was to record the nature of the original roof as it was exposed during essential repairs.  

The stone slates covering the roof had been removed prior the investigation but the sarking below was found to comprise pit-sawn Scots pine planks of a variety of lengths and widths.  Stone slates had been attached to the sarking using large headed hand forged wrought iron clout-type nails.  These nails were also used to nail the sarking to the rafters. 

Perth Lade

Wrought iron nails found in the sarking

The roof itself was found to be of common rafter form with most of the original rafters surviving, though a few had been reinforced or replaced in the 19th or 20th century.  All original timbers were found to be adze- trimmed softwood, probably Scots pine, and most were whole though some were halved and a few quartered.  Rafter pairs were connected at the apex with pegged mortise and tenon joints.

Perth Lade

The adze-trimmed rafters exposed, N Roof   

Perth Lade

An Assembly Mark, N Roof

On the N roof of the property (that aligned E-W) most of the rafters were mortised and tenoned into original sole plates and ashlar posts.  The sole plates on the N side rested on the external stone wall of the property, but those on the S side rested on brick walls that had been constructed on two steel I-beams.  These beams had been inserted when a major internal wall in the floor below was removed in the 19th or early 20th century.  Nine of the eleven rafter pairs on the N roof were connected to original collars by nailed lap joints with no dovetailing.

Perth Lade

Ashlar posts and sole plates along the N wall

Perth Lade

The original and replacement collars, N Roof

The S roof (aligned N-S with a gable overlooking the street) was of similar design to the N though original collars had been sawn off for a modern attic conversion.  However, inspection of the stubs showed that the collars had been attached in the same manner as the N roof.  In the S half of this roof the W rafters were mortised and tenoned to ashlar posts and sole plates resting on an external wall to the W.  On the E, they simply abutted the party wall of the next property.  Here the rafters also rested on two softwood beams that bridged a gap that was caused by the party wall being at an angle.  The N half of this roof had a ridge plate which rested on a small beam inserted in between the rafters of the N roof.  Rafter pairs in this part of the roof were not joined at the apex but were instead nailed to the ridge plate and each ran down to join valley timbers on either side. 

On the N facing side of the N roof at either side were two sets of vertical grooves in the original rafters marking the possible location of two 'cat slide' type windows.  A pair of cat slides were also found on either side of the S roof.  Two adze-trimmed bracing beams in the S roof pointed to the former existence of two dormers, one of which blocked a cat slide.  Later on, both of these dormers had been blocked.

Perth Lade

Bracing for an old dormer window, S Roof

Differences in collar widths and assembly marks suggested that the N roof may have stood alone prior to the construction of the S.  This pointed to the possibility that Hamilton's Land was at one stage set back from the High Street.  It is hoped that future dendrochronology of timbers will be able to provide precise dates for the two roofs and further clarify the precise building sequence.