Topical question - given the weather!

[NickB_99]

Hi,

Given the current weather, I was curious on this and felt this was a topical question worth sharing!

The building I work in was built circa 2005 and is about 3 floors high and approximately L shaped. It has pitched slate roofs with quite a steep pitch.

During the current weather, snow has built up and when the temperature warms up in the day, the slate roof warms and the snow loses grip and then whole lot on that face releases like an avalanche.

It dumps probably about 2-3 tonnes of snow from a height of 3 floors
From inside the building there is a large rumble and then you see it fall.
It then lands about 20-30 ft out from the base of the building.

Given that it could be onto the car park with people walking, cars etc or even worse off the other side, where it's public pavements outside work's premises, it could be quite bad and put someone in hospital (or worse).

I have seen significant snow fall off before - this happened a couple of times before (last year or so) but with the snow this year, the amounts are a bit greater.

It seems that there are some metal shutters at floor heights 1 & 2, but these only protrude about 6 ft. The falling snow clears them by a long way and they are ineffective. I suspect they were maybe there for rain protection walking around the path up against the building.

My question is.... is the building design defective and the architects/designers miss something?
Given we only lease this building, should they rectify it with some sort of guards on the roof to stop such large amounts sliding?

Company's response so far is to put notices on the door to beware of falling snow!!

 

[freddiemercurystwin]

I think you're thinking about things too much. What do you suggest? Ban pitched rooves completely or fit a ridiculously strong ludicrously looking snow gaurd for the once a year occurance? Maybe heat the roof so that snow can never settle on it?

 

[stuart45]

Remember the large icicles that used to hang down from the gutters like spears. You don't see them these days since loft insulation was brought in.

 

[NickB_99]

I think you're thinking about things too much. What do you suggest? Ban pitched rooves completely or fit a ridiculously strong ludicrously looking snow gaurd for the once a year occurance? Maybe heat the roof so that snow can never settle on it?

No, of course I don't expect pitched roofs to be banned or a heavy duty snow guard etc.
There must be some middle ground.

Surely a lower pitch would not have had the problem and wondered if something was overlooked originally.

Similarly, a more realistic fix should be possible - there must be some short baffles that are available to be placed horizontally on the roof or a few special tiles to achieve the same. There wouldn't have to be many or stick up far to stop a slide.

Maybe I do think about things, but I don't think that's a bad thing if there's a strong chance someone could get badly hurt.
The side road is a path to a recent new estate and there a lot of pedestrians going past (mums & toddlers etc).

 

[mointainwalker]

I live in a ski-resort in the French Alps where the problem you mention is common.

All roofs have some kind of snow retention devices, be it logs or metal-pipes on older roofs, snow-anchors of different sizes incorporated into the roof or a small "fence" at the edge of the roof . Added to that , the pitch is never very steep and gutters ( never PVC !!) are strong enough to support the weight of big lumps of snow whilst it is melting .

As well as diminishing the risk to passers-by, retaining the snow also increases the insulation of the roof .

The main thing though, are signs saying "Beware of roof-avalanche ".

I have seen one or two cars with the roof caved in when a couple of hundred kg of snow and ice have fallen but have only ever once heard of a fatality and that was an icicle falling off a cliff and smashing through a car that was passing underneath.

 

[freddiemercurystwin]

The major difference being that where you live MW major snowfall is regular and frequent and as such, these measures are necessary.

 

[mointainwalker]

You are of course right Freddy, although we don't have a huge amount at the moment at village level

I think however the OP has raised a reasonable point as in his/her particular location, this has now happened several times and is potentially very dangerous.

If all the company has done is to put up notices on doors then I think they are being very short-sighted because they have shown they are aware of the danger but are not taking reasonable measures to warn everybody who might be affected.. They should also put up signs outside visible to the pedestrians and cordon off the threatened area of the car-park.

Given the way of the world I would not expect anything to happen until there is someone injured which will make all the media because of its rarity and HSE bods will swarm out declaring all of Britain potentially very dangerous except in July and August ( and given recent summers, maybe even then too !)

 

[jm2000]

Given the amount of snow we get during the year...i would of thought that your office use a barrier fence to keep people from walking in the affected area.
You state it misses the building at the bottom so your right of passage should be changed until the snow has fallen using the barriers, with signs on the barriers warning of the danger. Its a quick and effective solution.

If or until we get as much snow as the snow resorts i doubt the designers will incorporate such systems into our roofs. And if we ever do we may all need to be looking at getting our roofs changed on houses already built as they were never designed to take the weight that amount of snow.

If as they say the climate is changing and we are to have much more snow things in this country will need redesigning...Look at the accident in Canada, where the weight of the snow was never put into the calculations and the stadium roof collapsed.

Me i ain't to sure its all down to us....but thats my point of view.

 

[NickB_99]

Thanks all, for the useful discussion.

I think on site we are aware and generally steer clear - you're right JM & MW, they did put up cones across the car park on Wednesday.
However, I'm not sure if we'd be allowed to cone off a section of pavement outside? Prob one to get the facilities guys to talk to the council about.

...Given the way of the world I would not expect anything to happen until there is someone injured which will make all the media because of its rarity and HSE bods will swarm out...

Times are hard enough in industry at the moment without us copping a load of bad press and then a chunky lawsuit to follow, if we injure an innocent passer-by!

I do accept it's not something common for the UK. I would realistically not expect any re-design - it is as it is.
The gutters are actually metal in construction and 'three sides of a square' in cross section - but below the angle of the roof, so no use in a slide.

I think the signs option outside is probably the most sensible for the very occasional time this is an issue in the UK.
I will suggest at work. H&S is everyone's responsibility!

A good Christmas to all.