In message , Phil L
writes
Don wrote:

:: Perhaps you would give me your opinion on another matter on which
:: I've been posting to a DIY ng.
:: The erection instructions for my greenhouse say it should be
:: anchored to the ground by drilling through the steel flange on the
:: base into the concrete slabs on which it stands.

That is very good advice and essential if the greenhouse is to survive
winter storms. Otherwise it will be shifted violently by gusty winds and
glass will break then strong wind can get into the structure it lifts
glass into the air and things get extremely dangerous.

:: I can see that I will have trouble in getting the screws in as
:: well as drilling the holes. I've been provided with 10 x 2" wood
:: screws & rawl plugs to be placed three each side of the 8' x 6'
:: base and two each end. Since I can't budge the greenhouse with
:: just the 3mm toughened glass in the roof. I can't imagine the wind
:: shifting it with the side glass fitted as well. I'm wondering if
:: there isn't a heck of a lot of overkill here and how many
:: gardeners do anchor their greenhouse down. My garden is quite well
:: sheltered by hedges and is on the leeward side of the house..

Don't underestimate the effect a severe gale can have on a greenhouse!

Even anchored down properly the thing is still vulnerable to aluminium
struts buckling if the wind speed gusts exceed 90mph.

It is also a bit worrying that you have a partially glazed greenhouse.
They are at their most fragile when part assembled. The structure relies
on the glass for part of its rigidity and can be a lot more easily
crippled by wind loading when partially assembled. Always work on a
still day.

If you've not already glazed the lower parts it will be easier to get the
drill in and drill through the steel, change the bit to a masonry one and
drill into the concrete and get it screwed down...if you have already glazed
it, it could prove to be a bit of a headache, unless it's easy to just take
a few of the panes out to do the job?

It is definitely worth anchoring down well. Otherwise it is only a
matter of time before a winter storm annihilates it.

Regards,
--
Martin Brown