February 1993 Report

ASCOUGH & ASSOCIATES

REPORT OF AN INSPECTION OF ST JOHN'S CHURCH, DUDLEY

1. INTRODUCTION

1.0.1    The report was carried out to the instructions of the vicar, Reverend J. Knights, who together with the PCC had become concerned about the expenditure which had already been incurred, and other expenditure that was predicted to be necessary to deal with dry rot in the roof structures.

1.0.2    Inspections were made in January and February, one day when there were heavy rain showers following a long period of relatively heavy rainfall.

1.0.3    We are required to say that we have not inspected woodwork or other parts of the structure which are covered unexposed or inaccessible and we are therefore unable to report that any such part is free from defect.

1.0.4    It should be noted that this is a report which limited to the elements of the structure of the property. It is not a structural report in the sense used by a Building Surveyor or Architect. It is intended to deal with the strength, stiffness, stability and durability of the structure only. Reference is made to matters beyond the scope described only where deficiencies are found which ought to be dealt with in order to avoid problems with the structural elements in the future. 

2. BACKGROUND INFORMATION

2.0.1   The initial contact was made by E.L. Lloyd Hughes FRIBA, the church architect who explained that he was now semi retired. He also explained that there had been considerable difficulties with dry rot in wallplates, truss ends and other eaves timbers on the south side of the church and that the costs of repairs had become a very great burden to the church.

2.0.2    Copies of the quinquennial inspections of June 1981, March 1987 and January 1992 were made available, together with copies of the following documents which originated from Universal Damp and Timber Treatments Ltd (UD&TT)

2.0.2.1   Survey report dated 17th June 1992 with schedule and estimate

 2.0.2.2   Letter dated 2nd September with additional work schedule and estimate

2.0.2.3    Letter dated 11th September 1992 with work schedule and estimate

2.0.2.4   Letter dated 30th September 1992 with work schedule  

2.0.2.5   Letter dated 19th October with work schedule, specification and estimate

2.0.2.6   Letter dated 30th October 1992

2.0.3   The church was built in 1840, and it is understood that the roof of the nave was raised to allow the provision of the clerestory windows soon after.

2.0.4   All of the original slate roofing was stripped in the period between 1969 and 1981 and was replaced with Marley Modern concrete tiles. Reference material produced by Marley Tile Co Ltd suggests that such tiles are suitable for pitches as low  as 22.5°. All of the roof pitches of the church exceed that slope.

3. OBSERVATIONS

3.1   ROOF

3.1.1   The tiles were lifted in one or two places at the eaves of the low level roofs and the tile were found to be free from frost damage, or other defects. Surprisingly however, not one of the tiles was found to have been nailed or chipped. Also, the cutting of the last placed end tiles where they butted up to parapets was very poorly done.

3.1.2   Sarking felt was found at all of the places where tiles were lifted, but in every case it was found to stop short of the outer wallplate. it was in such brittle condition that it could be crumbles in the fingers with no effort. A 100mm square piece dropped from the aisle eaves to ground level shattered into a large number of smaller pieces.

3.1.3   The recent work to the flashings to the north aisle roof was examined at one location, and appeared to have been competently done.

3.1.4   Roof timbers - rafters and wallplates were found to be damp when tiles were lifted at the eaves of the stairway roof to the south of the tower.

3.1.5   The church appears to have much of the original cast iron guttering still in place, and had the usual problem of leaking joints. There was evidence of patching with self adhering bands and other shortlived materials over the years. A relatively small proportion of the gutters had been replaced with modern plastic.

3.1.6   The original gutters were supported either on small sandstone corbels or continuous corbels of sandstone. A sufficient number of the small corbel stones had broken for the support of some lengths of the gutters to be questionable.

3.1.7   It was noted that in places, the gutters could be seen resting on piles of rust.

3.1.8   The roof over the entrance to the vestry had the original lead flashings on it. At eaves level, beneath the gutter there was a cover flashing which was in a single long length. It had cracked in places and had been repaired. A standard overcloak flashing had been provided at the top, with secret gutters in long lengths at the other edges. Stepped flashings covered the turned-up edges of the secret gutters.

3.2 WALLS EXTERNAL

3.2.1   The outer faces of the outer walls of the church were built of grey limestone blocks of varying size, the course thickness varying from about 225mm at plinth level to as little as 50/60mm near to the eaves. The original mortar appeared to be lime based. A light brown sandstone had been used for dressings to window and door openings, string courses and other decorative features. It was noticeable that in many places the sandstone was considerably decayed.

3.2.2   Externally, the pointing mortar appeared to be cement rish in most places, and had been carried over the arrisses of the stones.

3.2.3   The inner parts of the walls were of soft burnt clay bricks laid in lime mortar. They were fully plastered internally with the exception of the upper levels of the tower, and spaces under the stone stairs to the gallery.

3.2.4   At the junction of the south wall of the chancel and its east gable wall at high level, there was slight evidence that the gable is moving outwards - similar evidence was found on the north side. There also seemed to be a slight bulge in the gable wall near to the centre, on a line linking in the kneeler stones. It seemed to be quite small - maybe 75mm.

3.2.5   Weather has been getting into the gable peak of the east wall of the chancel and there is some cracking of joints in the masonry of the top 1.5 metres or so. Water running on the top of the copings is getting in through open joints and seems to be responsible for the movements that can be found in the vicinity of the kneeler stones. In each case the cause of the cracking seems to be the action of frost on saturated masonry.

3.2.6   On the north side at the top of the north aisle wall the gutter was placed directly on top of a continuous projecting stone which in turn rested on projecting dentil stones. Pointing which had been put in beneath the gutter (between it and the stone) had been disrupted and pushed outwards. Towards the west end it could be seen that the gutter was sitting on a thick bed of rust. There was plenty of evidence of high level dampness as a result of gutter leaks. There was the usual slight indication that the east gable of the north aisle had been displaced outwards.

3.2.7   In the north eaves of the nave there were two rainwater pipes at roughly third points. The eastern pipe had been changed to plastic. The old cast iron gutter stopped at a hopper head above the new pipe and a new length of plastic gutter had been put in to the east of it. It was difficult to understand how the joint between the gutters had been made. The two stop ends had been brought together, and it looked suspiciously as if the set up relied upon shortlived adhesive tape. The support brackets for the plastic gutters looked to be too widely spaced.

3.2.8   The west end of the north wall of the north aisle was particulary damp internally, and could be seen to be significantly cracked internally - in spite of having been repointed at least once before. The source of the dampness was traced to a leaking joint in the guttering. The gutter could again be seen to be resting on a pile of rust, and it was considered that there was a strong possibility that the development of the rust had disrupted the falls.

3.2.9   At the head of the window to the left of the western rainwater pipe in the same general area, it look as if the arch st9onework had become loose. Some of the arch stones were quite badly cracked and it looked as if there was a section of facing which was liable to fall.

3.2.10   It could be seen that much of the leadwork of the south aisle roof had been newly replaced or refixed. The detailing was examined at eaves level using a ladder and whilst the flashing of the roof tiling appeared to be generally satisfactory, it was felt that the new undercloaking which had been provided to the gutter, was possibly in excessively long lengths for its coding. It had been simply overlapped where it had been jointed, instead of being provided with anti-capillary detailing.

3.2.11   From examination of the correspondence, it seems likely that nothing had been done to deal with the defective sarking felt.

3.2.12   At the south side of the nave roof the gutter had been replaced with plastic.

3.2.13   At each end of the south wall of the nave at high level, the masonry again showed slight signs of problems related to unrecovered thermal expansion.

3.2.14   There was an unpleasant junction where the nave roof met the south east corner of the tower. there were apron flashings which seemed to be disrupted and which appeared to have been repaired with a self adhesive flashing material.

3.3 WALLS INTERNAL

3.3.1   No significant problems were found in the entrance vestry. It had the same gloss-painted finish found everywhere else. Slight cracking was noted in the south wall but nothing to suggest significant problems.

3.3.2   Upstairs in the Rose Vestry there is evidence of the recent dry rot repairs by UD&TT Ltd in a patch of rough re-plastering at high level on the west wall and some missing ceiling plaster at eaves level in the south wall. An original purlin ran into the newly re-plastered area. A small penknife blade could be pushed easily into the top half of the purlin near to the wall and the blade came out smelling of preservative.

3.3.3   A new length of wallplate could be seen which had been crudely halved onto the existing. It is known from the descriptions provided that the replacement timbers had been partly wrapped with felt, and part of it could be seen. The newly replaced timber appeared to have been very roughly coated with a dark stain. If it was intended to be a preservative treatment, it did not appear to have penetrated the surface significantly.

3.3.4   At the east end there is clearly evidence of continuing longstanding damp penetration, and hence, concealed, untreated rot. It seemed extraordinary for it to have been left behind.

3.3.5   The east wall of the Rose Vestry has been lined out with hardboard.

3.3.6   At the point where the electricity cable entered the church - at the south west corner of the south aisle - the ground floor had been rescreeded in front of an old, now unused entrance door. There was also evidence of work to the joinery. The plaster in the general area had been replaced in the manner used by the dry rot treatment by UD&TT Ltd.

3.3.7   No problems were found with in the entrance porch beneath the tower, nor in the spaces beneath the stone stairs. There appeared to be vertical ventilation shafts in the understair compartments which were later found to have once connected to the 2nd stage of the tower. It is worth noting that there is an exposed softwood timber lintol in one of the understair spaces. It is indicative of what may be found over the openings elsewhere.

3.3.8   The spaces which contain the stone steps which go up into the tower and serve the balconies show evidence of penetrating dampness at high level, particularly at the southwest corner. One of the places where the eaves were temporarily opened up, was above that corner and both the rafters and wallplate were found to be damp. the fact that the dampness could be found on top of a rafter, well up from eaves level, was a clear indication that water penetration was not confined to the eaves and gutters. On the south side, the dado had been replastered and there was a plasterboard ceiling.

3.3.9   On the north side the stair flight was completely covered with old ladders, doors and other unused items, mostly timber. There was so much that it was impossible to get up or down the stair. It could be seen that there was one wall where the plaster had been completely removed, there were areas where the ceiling plaster had fallen, and there had been much making good of plasterwork over many years.

3.3.10   On the south side of the balcony the stained glass windows were noted to be stiffened with steel or iron bars. The bars were corroding and in doing so, had damaged the stonework of the window surrounds. In addition to the damage caused by the window bars several instance were found where the stonework had been damaged by built-in iron cramps or dowels.

3.3.11   the south balcony is the area in which most of the recent dry rot rectification work was done. In the course of the work, pews were removed and the railings which crossed the window openings were taken down. Many of the timbers which were removed had simply been dumped into the spaces between the pews without any regard for their worth and the need to protect them from damage. The railings have been replaced with single planks screwed to the wall.

3.3.12   The direction of the floorboards of the balcony suggested that the joists went into the wall that had been replastered. It is surprising that although it was felt necessary to strip the whole of the wall plaster in order to irrigate the masonry, and although the walls are clearly suffering from dampness below the balcony, no serious attempt seems to have been made to lift boards against the outer wall so that condition of the joists could be inspected. In the few places where loose boards allowed inspection, it was found that the spaces contained significant amounts of accumulated debris, at least some of which clearly related to the recent remedial works. In fact, the floor joists  did not go into the outer wall, but were surprisingly meanly sized and were supported by a trimmer which ran close to and parallel with the wall. In the places that could be examined, the gap between the trimmer and the wall was completely filled with debris. The trimmers spanned between the cast iron trusses which can be seen beneath the ground floor ceilings. The ceiling joists are separate from the floow joists because whilst the floors are level, and stepped, the ceilings slope.

3.3.13   The floorboarding in the areas where the work has just been done was generally in poor condition, and far too much of it was not fixed down. In spite of the fact that so much was loose, there was no evidence that the vulnerable portions directly in contact with the walls had been routinely exposed for inspection.

3.3.14   Almost all of the stained glass leaded light windows are considerably buckled, and not all of the buckling was associated with corroding ironwork.  

3.3.15   Dealing with the roof of the south aisle from the inside, starting at the eastern end. The outer end of the first truss appeared to have been treated with preservative. It had a fair number of what seemed to be 12mm diameter holes drilled into it and there was an oily looking staining of the new wall plaster.

3.3.16   The trusses were supported at the outer wall by cantilevered cast iron gallows brackets, and a single heel bolt had been passed through the principal rafter of the truss, its tie, and the cast iron bracket. In addition, the cast iron brackets were bolted to the wall with two iron bolts passing through lugs on the brackets. The original iron bolts had been replaced with corrodible steel put through the original cast iron lugs.

3.3.17   The second and third trusses had been repaired by adding external plates to their bottom ties. The heel bolts  had been removed in the making of the repair and had not been replaced.

3.3.18   The fourth, fifth and sixth trusses all appeared to have been treated with preservative, and the lugs of the cast iron brackets had been rebolted.

3.3.19   At the base of the fifth truss more details of the support arrangements for the cast iron brackets could be seen because a piece of the covering plasterwork moulding had broken off. It was clear that the base of the cast iron bracket was built into the masonry, had rusted, and in so doing had expanded and simply burst the moulding off. In falling, the moulding had broken. Some thought appeared to have been given to refixing it, because there were two new nails holding the lowest section in place.

3.3.20   It was only possible to make a very limited inspection of the balcony on the north side, because the components of a dismantled organ had been thoughtlessly dumped in such a way as to prevent any access. No attempt seemed to have been made to keep it in any order, and some pieces were clearly damaged.

3.3.21   At the westernmost window on the north side there was particularly sever damp penetration which extended right down to the blocked up doorway below it on the ground floor. The cause was found during the examination of the roof above it.

3.3.22   One problem which could be found throughout the building to varying degrees was particularly severe at this location. The sandstone masonry of the window surrounds had been painted with a paint which prevented moisture evaporation. In many places, the paint film had failed or been damaged, and the concentration of moisture movement at the break had caused serious breakdown of the stonework. Incidentally, it was initially thought that the reveals of the windows of the aisles at both high and low levels were of finely jointed stonework. The damage caused by the dampness revealed they were in fact beautifully lined out, rendered surfaces.

3.3.23   The moulded plaster base of the cast iron bracket of the westernmost truss on the north side had been forced off by corrosion. At the next two or three trusses, water staining of the plasterwork could be seen directly beneath the cast iron brackets, suggesting that  similar developments were under way at those locations.

3.3.24   Looking from the north balcony across the nave to the south side, it could be seen that, working from the east end, the third truss had a splinted repair. There was noticeable dampness in the plasterwork at the end of the fifth truss, which coincided fairly closely to the position of a rainwater hopper on the outside.

3.3.25   No signs were found of any misbehaviour which could be attributed to the upward extension of the nave, but it seems odd that only the central two of the nave trusses had been provided with tie rods.

3.3.26   The arcades, the supporting columns and the internal walling in general all appeared to be in good order, as was the balcony construction away from the outer walls.

3.3.27   There were no signs of the sort of misbehaviour which can often be found when walls are built of components with such differing properties as natural stonework and burnt clay brickwork.

4. TOWER

4.0.1   Access into the tower to make the inspection was exceptionally difficult and it was necessary to arrange for a ladder to be  brought in specially for the job.

4.0.2   Structurally there seemed to be few problems. There were the usual vertical cracks in the brickwork above the windows, but nothing to give cause for concern.

4.0.3   The roof structure appeared to be in sound condition, all of the timbers appearing to have been treated with creosote, presumably when the rest of the building was retiled. It was not possible to get out to inspect the roof covering because the access hatch had been nailed. One matter which did give cause for concern however, was the lack of a proper support for the lead sump which dealt with the run-off from the roof and gutters.

4.0.4   At the time of the inspection there were a large number of pigeon carcases and a 10-15mm layer of droppings on most horizontal surfaces. The mesh fixed over the louvres was noted to be sufficiently distorted to allow relatively easy ingress, but obviously trapped any bird which was foolish enough to get in. There were old nests on the ledges at the foot of the louvres, outside the mesh.

4.1   BOILER HOUSE

4.1.1   The boiler house was located beneath the eastern end of the north aisle and access to it was via a stairway in an open well surrounded by pointed metal railings. The boiler was gas fired, and the gas meter was located in the open well, under a lean to roof.

4.1.2   There appeared to be no way for rainwater to get out of the open well, and it was noted that many of the lower level bricks were suffering from frost damage.

4.1.3   The door had been replaced recently and it is understood that the area had a thorough clean out. However, it was noted that there were two pipes lagged with what looked suspiciously like an asbestos based material disappearing into a duct beneath the floor of the church. The lagging had been damaged and was lying around on the floor of the boiler house, in, on and around piled up timbers, surplus roof tiles and other items.

4.2    GENERAL MATTERS

4.2.1   Most of the rainwater gully gratings were noted to be clogged up with leaves or litter and many were also silted up. At times of heavy rainfall, little of the rainwater goes into the gullies - most clearly discharges into the ground.

4.2.2   There were three iron opening lights in the nave clerestories on each side, and similar number in each of the aisle windows - 12 in total. They were all very badly rusted, inoperable and likely to cause damage to both the stonework and the leaded lights.

4.2.3   It is strongly suspected that the lightning conductor installation is well outside present day recommended standards.

4.2.4   The boundary wall with the old school looked to be in a poor state. It was retaining about 1.8m of soil with a sloping bank at about 30° above it. Thus the wall was retaining the best part of 3 metres of churchyard soil. It was of random rubble stonework set in very hard cement mortar and had a number of significant bulges. Buttresses had been contructed to deal with two bulges close to where there appeared to be a closed up opening - possibly where there were steps and a path linking the school to the church. The question of whether the church is responsible for the upkeep of the wall will need to be determined. If it is, it is likely that remedial work will be required with the quinquennium.

4.2.5   Much the same thing applied to the boundary wall at St John's Road where the wall retained about 700mm of soil. There were trees in the churchyard very close to the boundary which were clearly pushing the wall about.

4.2.6   In the architect's quinquennial reports reference was made to the cracking of the concrete pavings on the north side of the church. Because such movements can give useful early warning of ground movement, the pavings were examined. The worst affected parts were found to lie above a steep soil bank, which exhibited signs of soil creep.

5. DISCUSSION

5.0.1   The problems with dry rot are clearly the results of defects in the detailing of the roofing. The fact that the original slate roof seems to have lasted nearly 100 years, without significant problems (there is no evidence of earlier structural repairs) suggests that the problems were probably created during or by the re-roofing.

5.0.2   Bituminous sarking felts did not become widely used until after 1945, and it is therefore deduced that the felt was installed when the roof was stripped and retiled some 20 years ago. It is something of a shock therefore to find that the felt has deteriorated to such an extent. the Marley Tile Co Lts were consulted about the matter and have advised that the watertightness of their roofs depends on the integrity of the felt.

5.0.3   At every location where the eaves were opened up, it was found that the sarking felt had virtually completely disintegrated, well before it reached the gutters. Even where the recent remedial work had been done, no attempt had been made to replace damaged areas.

5.0.4   It is a matter of concern that there were so many indiacations that the roof retiling had been badly done. No nails or clips were found in any of the areas examined, in spite of the fact that the manufacturer recommends that all perimeter tiles are nailed. The cutting of tiles at abutting ends was very badly done and also, at the small number of places examined, evidence was found that the original lead flashings had been damaged and distorted. The whole matter of the re-roofing seems to be questionable.

5.0.5   It is a matter of concern that in an area where the original flashings had not been disturbed, where there were no loose tiles or missing flashings, water was found to be getting onto a rafter well above eaves level.

5.0.6   It is important to note that the self weight of Marley Modern roof tiling is about twice the probable weight of the original slating. No obvious structure misbehaviour attributable to the doubling of bthe long term stresses was noted, but the rate of deterioration of structural timbers will undoubtably be accelerated by the increase.

5.0.7   There is little doubt that there are two main water penetration problems. The dampness in the masonry stems principally from defects in the guttering system but a significant part of the rot problems of the roof timbers is attributable to generalised failures of the weathertightness of the roof coverings, mostly the flashings and the sarking felt problem.

5.0.8   The original gutters were of cast iron, and would have been jointed with red or white lead. Such jointing would have dried out and would have needed periodic renewal - a job which would normally be done routinely whenever the gutters were repainted. Part of the inspection was made during wet weather and special attention was made during wet weather and special attention was paid to gutter leaks. There was no doubt at two locations where the masonry was noticeably damp the problem could be tied directly to such defects.

The dampness in the vicinity of the central pairs of clerestory lights on the north side of the nave, is the direct result of a gutter leak. The large patch in the vicinity of the blocked up doorway at the west end of the north aisle can be traced to a similar defect.

5.0.9   Some sections of guttering have been replaced with plastic sections, and it is considered that the saving which was made will prove to be false economy. The material are shortlived in building terms, becoming brittle as they age, especially when they are exposed to strong sunlight. Even at this early stage it can be seen that the gutters sag between the brackets which have been provided. In addition, the gutters on a large building and their supports need to be strong enough to cope with the large amount of snow which having fallen onto the nave roof, can be expected to slip off in a thaw. Anything which falls off the nave roof  is then available to slip off the aisle roofs. The size of the nave roof far exceeds 'domestic scale',  but domestic scale details and fixings have been used.

5.0.10   Cast iron replacements for most gutter sections are available. cast iron gutters 100 years old are frequently found to be in reusable condition, and if carefully taken down, cleaned, painted and rejointed with synthetic rubber seals will give many more years of satisfactory service. It is important that replacement seals should always be of the type that is compressed by bolting up, rather than the types which rely on adhesion. (Seals which are compressed should not fail because of drying out).

5.0.11   Where the original gutters were still in use, they were found to be supported by continuous stones at aisle eaves level and by intermittent corbel stones at nave eaves level. It is known that the nave roof was raised some time after the church was completed, but the present detailing suggests that the eaves stonework was re-used.

5.0.12   One of the weaknesses of using stonework to support C.I. gutters is the difficulty of dealing with the rusting that arises as a result of the trapping of water between the surfaces. The provision of packs to lift the soffit level above continuous stonework can help, but frequent painting is the best long term defence.

5.0.13   There are places where the gutters can be seen to be sitting on little piles of rust. Rusting is an expansive process, the product occupying something like five times the volume of the original material. It can also generate very large forces. It is unlikely that the rusting will occur uniformly, and the consequence of neglect will almost certainly be damage to the gutters and/or broken corbel stones.

5.0.14   The general form of the chancel and nave roof does not look good on initial inspection, because essentially the timber trusses form untied arches. However, the nave roof has two twisted iron or steel tie rods to the trusses on each side of its centreline, and there is no doubt that they have had a beneficial effect. It is quite possible that they were added when the nave roof was added, since when the roof was lower, the arches would have been able to take support from the aisle trusses. Before the extension was made, it is likely that the springing points of the arch trusses of the nave roof would have coincided with the apex of the aisle roofs - in fact the roof may well have been entirely in one plane. No structural problems were found which could have been associated with the raising of the nave roof - in fact it was so well done, that unless the facts were made known beforehand, the one or two confirmatory clues which were found, might well have gone unnoticed.

5.0.15   The chancel is sufficiently short to make the lack of tying less important, if the timbers are all in good condition. However, it is considered that further tie rods should be introduced into both the nave and the chancel if the opportunity arises to put them in economically - essentially when there is suitable access scaffolding available. The roof structures would then be somewhat less vulnerable to serious misbehaviour, in the event that there is exceptionally bad weather. kor undetected decay of an important element.

5.0.16   Because many of the major problems of the church can be put down to the effects of water entering the fabric of the building at high level, both the gutters and flashings should be given a very high priority and very careful attention.

5.0.17   The flashing details used by UD&TT Ltd were investigated and were found to be correct in respect of the ends of the runs of tiling. The lead flashings put in under the gutters need further investigation, because the lapped joints used look as if they may allow water to get through by capillary attraction. It is also possible that the lengths of the pieces of lead may be found to be more than is currently recommended.

5.0.18   Probably the most widespread, damaging and intractable problem that was found was the decay of the sandstone hood moulds, string courses, window and door dressings. The problem clearly stems from the phenomenon that water running off a limestone onto sandstone will in certain cases, cause very rapid decay of the sandstone. The architect noted that much of the sandstone seemed to have been edge or facebedded, and whilst that does seem to be the case, there is no doubt that the principle cause of the problems is sulphate attack. The principal source of the sulphates is almost certainly rainwater washings from areas of limestone. The matter needs the attention of a specialist in such matters. In the meantime, attention should be paid to the risk of dangerously sized pieces of stone falling from the building without warning. Periodic inspection with binoculars is probably enough, coupled with with the removal of pieces which can be seen to be loosening.

5.0.19   In the matter of the treatment of dry rot, there is a growing body of opinion that provided that sources of moisture are eliminated, and well ventilated conditions are provided, the need for rigorous pursuit of every last vestige of dry rot mycelia particularly in masonry is not necessary. The organism will simply die back and become dormant.

5.0.20   Provided therefore that timbers which have been damaged are cut out and replaced with treated material, those which have been at worst risk are also treated with preservative, and good ventilation is provided, no further action need be taken. The elimination of sources of moisture is by far the most important factor. With that in mind, consideration of the weathering and ventilation details at the eaves is a matter of primary importance.

5.0.21   It is thought unlikely that the new concrete tiling itself will be leaking, but if it is, the poor condition of the sarking felt underlay is obviously a serious matter. The question of whether modern tiling systems depend on sarking felts for their weather tightness under extreme conditions is a matter which should therefore  be taken up with the Marley Tile Co Ltd.

5.0.22   One disadvantage of the use of a sarking felt beneath tiling is the restriction that it imposes on ventilation. Because of that, careful consideration and high priority should be given to the provision of a good level of ventilation, particularly at eaves level.

5.0.23   It was noted that little if anything seemed to have been done in the course of the recent dry-rot treatment programme to expose and check the condition of the gallery timbers, particularly in places where evidence of excessive dampness can be found in the outer walling at ground floor level. It seems odd for instance that there has been work to deal with dry rot at the southwest corner of the south aisle at ground floor level, but that nothing appeared to have been done to the gallery floor, which lying between two treated areas, would be expected to need attention, or at least a thorough investigation.

5.0.24   Two boards should have been lifted wherever they butt up to the outer walls, and the joists and joist ends should have been checked. All debris should have been refixed with screws, again making provision for ventilation.

5.0.25   The heel bolts which were omitted at the two places where truss end repairs were made to the aisle trusses served as a useful safety feature should the lugs or theirb fixings fail. It would be interesting to hear from UD&TT Ltd whether alternative arrangements were made.

5.0.26   It has to be said that the general standard of UD&TT's cleanliness, protection of adjacent areas and furniture, and care of items which were removed was very poor. In one of the places where rubbish was temporarily dumped, they have left behind rotten timber and bits of plaster. The contractor should have bagged up the material and carried it out, and not left rot damaged timber lie around in the building. Ten pews had been taken out, they were not denailed, and just appear to have been thrown down. There were no signs that they had been marked to show where they should go back.

5.0.27   Most of the rails and balusters which had been taken from across the windows and had been replaced by the crude single board rails were still in the church and seemed to be in perfectly sound condition. There were no signs of rot in the ends of the handrails, where they had been sawn through, which is interesting because they had obviously been bedded into the walls. There was one case where the handrail was missing and it is possible that it had rotted away. It would be interesting to know why the sound railing were not simply left in position.

5.0.28   One of the major problems with the building in general stems from the fact that the limestone is relatively impermeable. The mortar being very hard, and seemingly cement- rich is also impermeable. In heavy rain, there is therefore a tendency for water to simply collect and run off the face, when more usually much would have been absorbed.

As a consequence, whenever there is a defect, such as a cracked joint, relatively large volumes of water will be fed into it, and will wick into the wall, causing a localised wet spot.It is thought that there is little that can be done to alleviate matters, but again a specialist might be able to suggest a solution.

5.0.29   The copings of the upstand parapet are a good, if extreme example of the process. Water obviously travels down the steeply sloping stonework and gets into any open joints. One of the effects of that is that the coping stones are being disrupted by water which is trapped underneath them, freezing and lifting them. The solution may be the provision of a lead covering to the copings.

5.0.30   Most of the outer walls of the church had been pointed with what appeared to be a cement rich mortar, much of it feathering over the edges of the stones. Such mortars are damaging and ought to be avoided. In the future management of the building, the strength of the mortar ought to be reduced whenever repointing is undertaken and its detailing should also be improved to eliminate the damage which is being caused by feathered edges deflecting surface water into the joints.

5.0.31   All buildings move as their temperature increases or decreases and larger buildings move more than smaller ones. Also if a wall is in cintact with a massive abutment, such as a heavy tower, it will be prevented from moving by the abutment, and can therefore be expected to behave in a similar manner to a building of twice its length. The evidence of such movements is slight and is rather less than expected, probably because the church is well heated (in building if not in human terms) and the fabric is maintained at a reasonable even temperature.

5.0.32   No signs of problems were found of problems with the foundations, in spite of the fact that rainwater has clearly been pouring into the ground at the gully positions for a very long time.

The fact that the boiler house is tucked under one corner of the building, and that there are no problems to be found in walls which are partly directly above and partly of it, suggest that the foundations are excellent.

5.0.33 The problem with the concrete paving on the north side stems from the instability of the soil bank on which it is placed. It has been cut far too steeply.

5.0.34   The disposal of rainwater at ground level gave some cause for concern as all of the gully gratings were covered with leaves or were blocked with sediment. Because it is difficult to keep on top of leaves and wind blown debris, the use of back inlet gullies is normally considered to be more appropriate. With such gullies, the rainwater pipes are connected directly to the gully below the grating, which gets rid of the problem of grating blockages. However, in common with all other types of gully which incorporate water traps, they must be cleaned out at least once a year, possibly more frequently in some places. A date should be set each year for the cleaning of all gullies, and the checking of gutters. It is always far more economical to avoid problems than deal with the consequences.

5.0.35   There is concern about the dry-lining which has been applied to the east wall of the Rose Vestry. It really ought to be taken off to find out why it was thought to be necessary, and if there is a problem, the underlying cause ought to be dealt with, not the symptoms lined and to deal with the problem not the symptoms.

5.0.36   All of the masonry had been painted internally with a paint which appeared to all intents and purposes to be impermeable. As a consequence, the normal patterns of the absorption of moisture and its release by evaporation had been disrupted. Thus whenever and wherever the paint fails, moisture wiocks towards the failure and either subsurface crystallisation or even frost, causes damage to the stonework. It is recommended that consideration  be given to its removal.

5.0.37   It is difficult to find a reason for the buckling of the stained glass windows. Some of it clearly relates to corroding ironwork, but the problem is more widespread. The most likely explanation at this stage is that it is a further symptom of the decay of the sandstone dressings. Sulphate attack is an exoansive process, and the expansion can be expected to operate in all directions unless it is physically prevented.

5.0.38   Under the Health and Safety Regulations currently in force, the church has a duty of care to its employees. As the asbestos-like lagging material in the boiler house has been damaged and oieces are lying about, if the material is identified as asbestos, the cleanup operation will have to be carried out by a properly licensed firm. The essential first step is to have a sample identified. It will be necessary to collect a baked bean sized piece, wrap it well in a polythene bag or two, mark it as suspected asbestos, and deliver or post to a testing laboratory. The Industrial Research Laboratories in Birmingham will charge £30 + VAT for an identification and report.

6. CONCLUSIONS

6.0.1   The church has a large number of serious problems, the primary causes of which are not structural. However, if they are not dealt with expeditiously, the recent history of the building demonstrates that they will very rapidly affect the structure.

6.0.2   Without doubt, the most pressing matter is the identification of the pipe lagging material. If as is suspected it is found to be asbestos, it will be necessary to follow the proper procedures for dealing with it. In the meantime, all keys to the boiler house should be impounded, and entry by unauthorised persons should be prohibited.

6.0.3   The next most pressing matter is the need to re-establish the watertightness of the roof. There will be an advantage in making two or three much larger explorations of the condition of the sarking felt, to establish whether the defects found are as widespread as suspected. If they are, it is unlikely that anything short of stripping and retiling the roofs will solve the problems.

6.0.4   In financial terms the stonework problem is unquestionably the most serious. It is not known whether there is a solution to the problem which would be significantly less expensive than replacing all of the sandstone. An attempt has been made to contact English Heritage to obtain the most up-to-date information, so far without success.

6.0.5   It is strongly suspected that the cost of the first three items listed and other smaller scale urgent work, may be so far beyond the capacity of the congregation to fund the necessary repairs, that unless a very substantial outside source of funding can be found, the building is unlikely to have a worthwhile future.

7.   RECOMMENDATION

7.0.1   In the light of what has been found, the whole matter of the future of the building should be reviewed.

 

D.J. Ascough                                                                                                     6th February 1993