Thatch Fires and Other Nuisances…

Living under thatch, a risky business?

Not really… I imagine more thatch roofs in Britain, were lost to neglect than have ever been lost to fire. But the illusion remains, that thatched roofs burn frequently and the occupier will soon be out of house and home… In fact there is no more risk, of a thatch roof burning, than a slate or tile one… Insurance company records, over two centuries, have proved this point.

The reason for this is that thatchowners generally, are very aware of where they live and take sensible and simple precautions, against fire… But when fires do occur, they can be rather dramatic and usually make the news. Some hints, on how to avoid this sort of unwelcome publicity, now follow.

To be avoided at all costs… However this cottage was renovated, rethatched and reoccupied, within a few months…

Some events, are beyond the control of the most careful owner… The property may be struck by a firework, on bonfire night; or even succumb to lightening. But apart from disconnecting the television aerial in a storm, there’s not much to be done about either. I’ve never heard, of any misadventures to thatch, from these perils…

It’s the more down to earth mishaps that may cause problems and these are very avoidable… The biggest risk lies in the fireplace. The most common cause of a thatch fire is when the chimney catches fire and leaks into the thatch roof, often through poorly maintained brickwork, as it passes through the thatch, near the ridge.

This chimney appeared in the page on listing, rising through many layers of thatch… It also clearly shows the dark stains of soot that have leaked through the brickwork. A danger sign that is normally never seen; except by a thatcher…

Also, if a wood burning stove as been installed, the temperature of the fumes entering the chimney will be increased quite significantly. So much so, that if used continually, the brickwork in a sound chimney, next to thatch, could become seriously hot…

The answer, certainly to the first of these problems, is to have any possible problem chimney lined. There are quite a few systems on the market, which the thatchowner would need to investigate. A good person to get involved is a reputable chimney sweep; who anyway should be employed perhaps twice a year, by the thatchowner, with any form of fire.

As the easiest way to prevent chimney fires, is to make sure the flue is swept regularly. Twice a year is best; certainly before the fires are relit in the autumn. The thatchowner should ask their chimney sweep, if they think all is well. They can often notice a problem, during cleaning. If any thatching work is being carried out around the chimney, the thatcher should check for any signs of soot in the thatch… A sure sign of the chimney leaking…

The best time to fit any lining is when works are carried out to the thatch. As will be seen it is not a good idea to have non thatchers on a roof, if at all possible.

A much rarer event are sparks, blowing out of the top of a chimney; setting the outside roof alight. This type of fire, if caught quickly, can be put out fairly easily. But once the fire reaches the inside of the roof space, then there is a serious problem…

The risk of sparks, falling onto the roof, can be lessened; by fitting a spark arrestor. However the problem with these is they get clogged with soot and after a time become a danger in themselves; as the one opposite! The solution is to keep freeing them up; perhaps every three months or so. But that means climbing on the roof; which can mean damaging the thatch…Thatched ridges, over six months old, do not respond well to being walked on… The coatwork is stronger by far, but needs care and experience to climb on.

These spark arrestors are not recommended in the ‘Dorset Model’; this is a set of guidelines originally created by the local authorities in Dorset. Basically they state that new build thatches should have lined chimneys 1.8 metres (5.9 feet) above any ridge; and that the thatch should be underdrawn by a half hour fire barrier. These guidelines have allowed the creation of many new thatched buildings, in Dorset and elsewhere…

It’s as well to mention here another problem, the thatchowner should be aware of. The damage that can be caused by non thatchers climbing on a roof; especially television aerial erectors… Their hooked ladders that work so well on tiled roofs, causes untold damage to any thatched ridge. Wooden liggers will not take the strain, unless very new… If a new aerial is required, try to get it done in conjunction with a new ridge. Better still, try and site it away from the roof altogether. This helps guard against the very small risk from lightening.

On the right, a nice new shiny aerial… But the wired ridge is now trampled down, around the chimney, pulling the cement fillet away from the brickwork… Time to bring back the thatcher.

The risk to thatch from fires, caused by oil lamps and candles has lessened; but their replacement can still cause problems… Electrical wiring has to be kept in good condition. Modern fuse boxes and earth trips are a great help. But the area at risk is in the roof space; any wiring here must be of the highest standard, as mentioned in the Dorset Model guidelines.

The main risk, to electrical work in the loft space, are cables being chewed by vermin. Mice and rats can be a nuisance, anything serious is rare. But major problems can occur, on properties that are set into a hillside or bank; or have access to the thatch over extensions. Especially if the property is left unoccupied for any length of time. Apart from any damage to cables, the thatch itself can suffer; as these rodents love chewing through thatch. Cereal straw being favoured over water reed… Private contractors and the local council can provide a lethal solution and they have access to more potent poisons, than are available to the thatchowner.

Another species of mammal, that may take up residence, are bats. All bats are protected and it is illegal to disturb them, or their nesting sites. The local wildlife trust should be able to give advice. There should be no problem, in sharing a roof space, with these fascinating creatures…

Whilst we are in the roof space, how about some loft insulation? Thatch does have excellent insulating properties but a single layered roof can be draughty and why heat the roof space, just to keep the mice warm…

With a new home, covered with thatch, modern building regulations mean there should be no worries about the chimney. And having a new roof, the owner may benefit from extra fire protection, in the form of a barrier of fire proof material; between the roof timbers and the thatch. If carried out well, this gives almost complete protection, against damage from burning thatch… This method can also be used before any single layered thatch is fixed, to an existing roof. But a lot of damage in a fire is caused by the water used to put it out… This is the half hour fire barrier mentioned in the Dorset Model guidelines. As with chimney liners there are several barrier systems on the market. With a completed thatch, a fire retardant spray could be used, these are said to give protection from sparks from chimney fires etc… I am no expert on either these spays, fire barriers or chimney liners; there is an awful lot of information about these on the internet and any thatchowner should check what is best for them. Bearing in mind that the vast majority of old thatched buildings have neither barrier or sprays, to prevent fires and have been around for a very long time…

In over thirty years, I only rethatched two roofs lost to fire and repaired two; which hopefully puts everything into perspective. Below, are the causes of these fires and others I have heard of…

A hot air paint stripper, used inside an upstairs window; igniting the dust, then the old thatch; on the other side of the ceiling…

A huge fire lit in an ingelnook, by new owners; who had not had the chimney swept or checked…

D.I.Y. electricals… Thankfully, most work now legally needs a qualified electrician.

A chimney fire, caused by jackdaws filling the chimney with nesting materials, during the summer. The owners, returning after a long absence did not check the flue…

Plumbers using a blowtorch in the roof space…

And sadly, a thatcher burning old thatch too close to the job. This was in the long dry summer of 1976; but even this is no excuse…

The main attraction… These Derbyshire cottages, caught light over a century ago. It seems that the firemen and locals were in much more danger, dancing around on the roof; than this building’s occupiers! It’s almost unknown, for a thatch fire to turn fatal. This is a major reason, why modern fire regulations have been relaxed; to allow so much more new building with thatch.

All these cautionary tales lead quite logically to the subject of insurance. As well as the internet, in an area with a lot of thatch, there may well be advertisements in the local press, for thatch insurance. Or the owner may be contacted by insurance agents through the post. This goes to show how low the risk really is. These insurers know that and want your business.

The premiums are higher than for other properties, but over the years the market has become quite competitive, so it pays to shop around. Owners with a mortgage should beware of insurance tied to the lender. Remember, that with any property insurance, you are insuring against the rebuilding costs and not the market value. The owner should allow for the worst case scenario; clearing the site, a complete rebuild and even accommodation while you are homeless. So it pays not to skimp, on the sum insured….

But cheer up, it will probably never happen…

This 1857 insurance certificate, from Hethe in Oxfordshire, shows how much and how little, has changed in the insurance industry… The value of the insured cottages certainly has altered! Yet the premium, of thirteen shillings and sixpence, is three times the rate for non thatched properties. What the policy calls ‘Doubly Hazardous Insurance’. This is basically, what is often charged today… Which seems a little unfair, as the fire brigade no longer relies on horsepower, to arrive at the scene; or the efforts of sweating neighbours, to power the water pump! On the plus side, William Mansfield had to pay nine shillings in duty; on his premium. A tax of around 66%. On non thatch properties it was 200%… Which puts any insurance premium tax, we now pay into perspective.