Hmm, so I went to the wiki page, (the glass centres own website seems to be host hijacked)
& "roof glass" is indeed an architects wet dream of "design influenced play" & all the stresses that places upon glass.
https://en.wikipedia.org/wiki/National_ ... rney83.jpg
"The National Glass Centre is constructed from glass and steel. Visitors can walk on its glass roof and look down into the centre below. There is a total of 3,250 square metres of glass on the roof, and it can hold 460 people on at any one time. Each glass panel on the roof is 6 cm thick"
Rust, leaks and broken glazing – and high repair costs – have been blamed for plan to shut ‘world-class’ venue ..so we have 1 of 3 if all the broken panels have been the 6cm thick units (unlikely given early required maintainence due to rust & leaks)
snippet..
GSSArchitecture considered various refurbishment options in its study of the building’s structure. It did not recommend the lowest cost option of more than doubling the maintenance budget and incurring one-off capital costs of £2.4m because of the future risk of structural failure. A second option was roof replacement at a cost £45m, and a third was a rebuild with a vertical extension at a cost of £72.3m.
..
Original build cost to 1998 opening was 17 million pounds, inclusive of 6.9 million lottery fund granted funding for the initial build (no idea of funding since) ..very poor outcome, looks like liability will go away as a face saving exercise.
Wonder what stresses would have been avoided if it wasn't a play area & merely a roof?
However, if you look at google maps streetview link & click walk around the building there is not much roof, more slab paving than anything, so it is misleading.
https://www.google.com/maps/@54.9134521 ... 384!8i8192
I can say that we had a 1960's outdoor, underground carparking & govt buildings shopping area near us that was eventually knocked down some 15 years ago, it was concrete slab supports, overlaid with grey concrete paving slabs, ..similar to this actually ..& it leaked like a devil, not least of all because design was open concrete guttering, metal downpipes into the carpark area which was partially open to the elements (central feature) ..not surprisingly it was a centrepiece of the "crap towns" book series. (
https://craptowns.wordpress.com/2012/10/18/huntingdon/ ) NB the crap towns pic was after it was done up "whilst waiting to be knocked down" a short term improvement spend that went under the bulldozer very shortly afterwards which did ease the repetitious slant of 1000 wonky concrete paving slabs a little)
The uppermost "walking area" access for shops etc, sloped & undulated for as long as I can remember, so I'm wondering what the weight effect of all that slab is on the underpinnings & membrane, there is actually very little glass roof surface area.