Theres a lot of snow on the roofs

[zaax]

Theres seems to be about a foot of snow on local roofs

How much snow can a modern roof take? Would opening the loft hatch help to melt the snown and keep the weight / depth down?

[Clot]

It could add to the roof's burdon! The heat could cause snow to melt and compact without leaving the roof allowing more to be added! If you wish to use a lot of fuel then turn the heating up, remove the hatch add make sure it melts quickly.

Overall, my take is that it would not be of benefit.

[Nightjar]

In 1963, the roof on our house survived, but the gutters were brought down when the snow started to melt and slide over them.

Colin Bignell

[The Natural Philosopher]

a typical TILED or SLATED rod is massively heavier than any snow its likely to collect this side of Novosibirsk.

The same cannot be said of shed felted rooves...

[MM]

On this morning's Farming Today This Week (6:30 am) a farmer interviewed said several barn roofs had collapsed due to the weight of snow, crushing and killing some sheep in one instance.

MM

[Bob Eager]

When we bought this house, the surveyor had some comments about the roof.

Originally slate, it had been tiled, tiles being a lot heavier. He said it was fine, but could have problems with much extra weight (e.g. snow). He suggested some extra support, which was cheap and easy to fit. Glad we did!

[pete]

I've got some scarey large icicles forming from my gutter (which is frozen and full of ice). Some are hanging over the front door - so it has to be closed gently to prevent the risk of getting skewered :-)

[Andrew Gabriel]

Looks like that's happening to neighbour's (new) roof. Also saw some in the high street where gutters are twisted right round, but snow has now gone (presumably no loft insulation). These are all slates - doesn't seem to be slipping down tiled roofs so much.

[Hugo Nebula]

The rafters and other members are designed to support a load of

0.6-0.75kN/m^2 (& 1.0kN/m^2 for roofs in the North of England over 100m above sea level). My maths and a trawl through Wikipedia suggests that this is about 750mm of powdery snow. If it were to 'settle' on the roof, that could be about 200mm of snow.

Within the design code there is a factor of safety of about 1.6 for imposed loads. Also, the main limit on timber sizing tends to be deflection, which will usually manifest itself before bending forces are exceeded. In addition, there are further safety factors included in the strength classes of the timber and the calculations.

A modern trussed roof is generally designed to the limit with no additional factors of safety, other than those required by the codes. A modern roof to a more traditional design, whilst more reliant on individual members (purlins, hips, etc), is more likely to be 'over-designed'.

In other words, don't worry.

[Hugo Nebula]

I sold a house like that. I managed to prove that, with extreme snow load, the bending forces on the purlins wouldn't be exceeded, but that there might be about 50mm deflection in them. As there were no brittle finishes attached to them, that wouldn't matter.

[dave]

Ask David Cameron - he's always on about fixing roofs while the Sun shines :-) Sorry, political, will get my...

[Doctor Drivel]

That bunch of Hurray Henry Old schoolboys (mainly from Eton) are out to line their own pockets. Not changed since the wicked witch was in power:

Extract from Ricardo's Law: House Prices and the Great Tax Clawback Scam by economist Fred Harrison ..........

In the 1980s Hesseltine led the Thatcher government's attempt to deal with the aftermath of the Toxteth riots. Hesseltine decide that inner-cities should be rehabilitated. Within a mile of Liverpool's city centre and Toxteth were 1,000 acres of of abandoned industrial wasteland. In London

6,000 of abandoned acres were in Docklands.

His twofold solution:

1.. Invest taxpayers' money in infrastructure to attract private enterprise. This delivered windfall gains to owners of adjoining land and raised the cost of rented accommodation to low income families. 2.. Exempt real estate from property tax. This attracted warehouse type of investment with low labour content to areas of high unemployment - of little help to the marginalised dwellers of the decaying hearts of Liverpool and London. Hesseltine did not understand that private landowners were as responsible for the dereliction which he observed as was 'the large-scale hoarding of land in the public sector'. When he was escorted back to Liverpool in 2006 by Cameron, it appeared that a future Tory government would repeat the mistakes of the Thatcher years. Hesseltine commended investment in capital-intense infrastructure that would make their assets highly valuable. ... ... The Thatcher government decided in 1980 that London's Docklands should be redeveloped. Its primary tool stood justice on its head. Instead of imposing public charge on vacant land - to force it into new uses [this also stops land speculating] - the government created an enterprise zone. One of the privileges was exemption from property taxation.

The result was predictable. Tax relief was capitalised into higher land values, and families which for generations had made Docklands their homes were pressurised out of the area. Those who did not own land were the losers. The windfall gains did enrich some people. Arnold Fulton purchased a plot of land in a derelict corner of Docklands for £650,000. Developers pursued him fending off their offers until he took £30 million.

[zaax]

thanks for that, I was when I saw a foot of snow on the roof opposite

[robgraham]

My under-timbered, shallow pitched, corrugated light plastic lean-to roof at the side of the garage gave me a warning yesterday evening when it started to drip through.

One of the roof panels was a recycled one and had the odd nail hole in the top of the corrugation, which is obviously not a problem with rain, but is one with melting snow. So at 7pm yesterday evening I was togged in full waterproof gear and shovelling the snow I could reach off this roof from a ladder. The dripping at least stopped.

One of this summer's jobs will be to replace this roof - bearing in mind the weight of wet snow, not that this is likely to be a problem now for another 30 years!

Rob