February 2021

15 Buckden Roundabout February 2021 Gatehouse Repair During the initial surveys, it had been suspected that the ex- isting roof was not an original feature of the Outer Gatehouse due to the nature of the materials and the method of construc- tion. This theory was confirmed after the removal of the rotten roof structure which uncovered signs of a much earlier vaulted ceiling formed with brick to match the shape of the three - centred Tudor, ‘ flat ’ arched openings. This brick - vaulted ceiling may have been rendered with a lime mortar. There is also evi- dence that the original roof had a solid top with a shallow slope finished with clay tiles or bricks. There are no records as to how or why this original structure was removed. It may have collapsed or been dismantled fol- lowing signs of cracking. Or it may have been removed by the Victorians during the construction of the ‘ book - store ’ which could have led to instabilities in the structure. This evidence has now been recorded with photographs and drawings as it will be re - hidden by the new roof structure. The remains of the brick vaulting have been consolidated and re- pointed using traditional ‘ hot - mix ’ lime mortar, with small are- as repaired using hand - made bricks to match the existing. De- tailed analysis of the original mortar was carried out by a labor- atory so that the new mortar could be closely matched. The construction work currently underway to repair the roof is being carried out by the leading conservation contractor, Mes- senger BCR Group, under the leadership of Conservation Direc- tor, Matt Webster, and the skilled workmanship of site manag- er and traditional plaster specialist, Kevin Deller. The new roof to the Outer Gatehouse is being constructed to a similar design as the existing roof but with improved detailing and better materials. However, as none of the existing timber structure was suitable for re - use, the roof is to be entirely new. The central beam will be formed with a pair of air - dried oak beams secured together with stainless steel fixings and a treat- ed softwood framing. The new valley is to be lined with a thick- er grade of lead sheet, with suitable steps and joints to match the recommendations of the Lead Sheet Association handbook for best practice. The roof is to be finished with natural Welsh slate so as to match the adjacent cottage and it is more suita- ble for use at the low pitch of 21 degrees. Owing to the presence of bats and the possibility that they may roost within the Outer Gatehouse, a survey was carried out by a qualified ecologist who recorded bat activity close to the Outer Gatehouse. The new roof is to be fitted with a bitumastic felt underlay rather than a modern ‘ breather - membrane ’ which is not suitable for bats as they can become entangled in the fibres. In addition, two bat boxes will be installed in an ad- jacent tree. The ceiling is to be reconstructed with traditional lath and plas- ter using hand - riven chestnut laths and a three - coat ‘ hot - mix ’ lime plaster. The decorative oak mouldings from the current ceiling are to be cleaned, re - stained and reinstated, providing continuity to the roof and maintaining the special character of the ceiling. Other concurrent works being carried out to the Outer Gate- house include essential repairs to loose and damaged bricks, particularly those to the parapet merlons, and the replacement of the cast - iron hopper and downpipe with traditional cast - iron rainwater goods supplied by J &.J. W. Longbottom. The work is due to complete in spring 2021 and the Outer Gatehouse will once again be able to welcome many more generations of people into the Towers. (Continued from page 14) Signs of the earlier brick vaulting Traditional tools and materials on site