They are not generally made to support hefty loads on their working systems. https://74ift6efyor7yetnvw6ia6bn2cvjmyzunob3bwjig7igqkryv7mq.webpkgcache.com/doc/-/s/wikimapia.org%2Fexternal_link%3Furl%3Dhttps%3A%2F%2Fnottinghillscaffolding.co.uk%2Findex.html