On the building of Sizewell 'b' a wall was left out until some machinery was fitted, I questioned what would happen if the machine needed changing. Answer simple knock down the wall again, so if a concrete wall can be considered as temporary, what is permanent? Seems the reactor is permanent, the rest is temporary only has a 50 year life.
So it the home permanent? The prefab homes immediate post war were designed to last 25 years but some still in use. But I would have said we expect to access cable joints in domestic every 10 years, new rules have reduced that to 5 years, the screws need testing at each EICR so the maintenance free spring loaded connector block does seem to be way forward.
First worked with them in 1980 so been around for over 40 years, the problem with early versions was you could not remove the wires, so needed enough spare length to be cut off and remade. A real problem when fault finding. Later versions had a screwdriver slot to release cable, and still latter they had built in levers, but I would not worry too much about reliability as MF as they have been around for a long time, likely as long as the Nuclear power station.
As to floor boards with writing on them saying JB below, it seems people just ignore it when fitting flooring, so rather pointless. It seems other trades don't worry, I remember fitting a bathroom extractor fan, the owner did not want the run on, and as the windows could be opened it did not need run on, next time visited windows changed to non opening type, seems window fitters do not read the parts of the building regulations.
In real terms experience and common sense must be used, a metal frame batching plant will shake screws loose, so you need to access non maintenance free quite regular, in a house brick built with wood beams, I have found junction boxes like this
with no problem 70 years old. And I have made cable joints using screw terminals which have be then potted and the screws can't work loose because they are potted. I would trust a jubilee clip holding the earth between two bits of SWA cable much more than the silly springs supplied with the kits. Both are potted so neither can move, but what is the contact area, under fault conditions will it overheat. The epoxy resin is the same as loktight. Once set nothing is working loose.
