There has been some discussion going on about corrosion of internal flooring, coving panels and its causes. Firstly it is not caused by water ingress from mopping out. London buses have never been mopped or washed out and no water based internal cleaning facilities were available at garages on the run in. All that was done internally on a nightly basis was a dry vacuum. Periodically buses were subjected to an internal clean and this involved vacuuming of the seats and an interior “wash” (more of a damp wipe) of the ceiling panels and surrounds, the floors were never washed as such.

You only have to look at the surface corrosion on the window surrounds to see what can happen over time in normal use and exposure to atmospheric moisture and condensation. These surrounds were scrubbed with wire wool and grinding paste on overhaul to restore the shine, the top deck with added tobacco stains was surprisingly not as bad as the lower deck, condensation not being as big a problem on the top deck, perhaps due to having opening windows on most buses at the front. However, what has made the corrosion of the floor parts worse is surface erosion caused by the movement of the plates against the mating surfaces where the fixings have come loose and reduced the thickness of the metal considerably, to a point where it has holed. Adding to this is surface corrosion caused by condensation, water and rain ingress through windows and more commonly after overhauls ceased, through the gaps between panels, mouldings and strap plates, none of which has been helped to dry out by the fibre flooring applied to tighten up the floor structure, this created moisture traps along the coving panel fixing.
Angled bright aluminium strips were fitted along the coving panel floor joint with the treadmaster tiling as a modification to keep the tiling fixed and give a water tight bond with seelastik applied to the rear but this practice no doubt ceased after Aldenham stopped overhauling these buses, they may well have been discarded when the wood fibre flooring panels were fitted.
When replacing floor joint covering strips and coving panels, they must be tightly fixed to reduce movement, over time all the 5/32 pop rivets were replace by 3/16 (4.8mm). If accessible check the fixings of the actual floor sections, if the rivets are loose replace with larger diameter ones and if accessible, replace every 4th or 5th rivet with a bolt with nyloc nuts to tighten up the whole structure. Bolts were used to secure the sections of floor to the floor bars particularly round the flywheel and gearbox trap and between the longitudinal seats where as a last resort LT moved to a marine ply floor sdection to replace the aluminium one here which had caused so many problems due to the excessive movement and wear in this area of the bus.

My bus number (if any): RTL 960 and an RMC