One might be forgiven for thinking that all my work as an architectural paint researcher consists solely of lengthy analyses of historic rooms and structures with a view to identifying their original appearance. Far from it, a certain amount of time is spent dealing with little colour “problems”, perhaps making adjustments to paint colours because it has been found that en masse they don’t quite work. It could be that colours considered “appropriate” for an historical setting are required. On other occasions I am asked to specify the type of paint that will satisfy various technical needs – something that might resist hordes of visitors or severe weather conditions.
A recent example of a paint problem concerned a church in North London. It would probably be best not to name it in case it is thought that this is considered critical, which it isn’t meant to be – merely illustrative of the kind of everyday problems that arise.
This early nineteenth century church had been the subject of a major refurbishment, during which time the exterior was re-rendered and the roof replaced. It appears that there has always been a problem with damp and that there was a history of paint failure in the SE corner, in particular.
Within a year, paint was flaking from the ceiling in the SE corner. From the shape of the flakes and the thin powdery deposit on the reverse of them damp was the most obvious cause. Although not apparent on site, when photographs were examined a slight stain could be seen in that area (see above). However, I was assured that the roof had been replaced and that the underside had been lined with Tyvek* sheeting.
Borrowing a ladder I climbed up the outside of the building to a small trap door that gave access to the roof space. This was one of the tidiest roofs that I have seen, being clean, well-insulated and very neatly sheeted-out with Tyvek. Carefully stepping from one joist to another (and mindful of the consequences of falling through!) I made my way to the SE corner.
The insulation seemed to be dry but I couldn’t lift it to inspect the underside. However, just above the area of suspected damp I noticed that the Tyvek sheeting had been pierced by the stanchion that had been installed to support the Fall-Arrest cabling erected on the parapet of the roof.
Leaving my newspaper spread out over the insulation as a tell-tale to detect drips I left to write up my report.
The key to all these jobs is thoroughness and looking for oneself not just accepting what one is told. I have also found that having experience with heights is a great bonus.
*A material made from high-density polyethylene fibre which allows water vapour to pass through, but not liquid water.
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