Tin over thatch - Slate replacement??

[Peely]

Our house has Tin over thatch roof, the main roof that is, the rest is mainly slate with some clay, the 2 outbuildings are both slate.. the Tin has seen better days and original plan was to referb and repaint it but this year we've been refused home insurance due to the tin over thatch section, I spent days trying to sort even the "specialist unusual builds" insurance companies but no-one will touch us. I started looking into putting it back to thatch but the cost of maintaining that thatch, waiting times and we would like to add 2 wood burners to heat the house so thatch would not be preferable for us.

I've been speaking to the CO about removing both the tin and that thatch and put another roof structure over the top keeping the historic roof structure in place then adding slate. it would be safer, give us the wood burners, better insulation. She didn't say no but wasn't keen. but the cost is huge.. - I'm feeling like I'm being painted into a corner, am I missing something or jumping to a naive (and expensive) solution?

 

[Cubist]

Sorry to hear this. When our place was first listed it too had a corrugated iron roof over the remains of its ancient thatch - and worse still the exterior oak frame had been clad in hardboard, of all things, painted to emulate a black and white timber frame. All that bit the dust when the house and its then attached barn were de-constructed to the ground and rebuilt beam by beam.

Your CO will I suspect, while sympathising, prove less than helpful if not obstructive. It's their 'mission default' stance I'm afraid and it can be difficult to change their minds. An extreme possibility is that you apply for the property to be de-listed but that can be a challenge in into own right but I'm wondering if you've considered all the alternatives? One thought that comes to my mind is that the corrugated iron was probably installed decades ago and consequently the thatch beneath it will have been decaying for all that time, as will its fixings to the old roof structure. If you were to remove the iron theres a high probability that much, if not all, of the thatch would simply disintegrate and have to be removed - why would you bother re-thatching if, say, you planned to to put new iron sheath over it? Would that not also satisfy your insurers demands?

As a matter of interest has your insurer articulated any particular reasons why they feel your roof is more vulnerable and/or is their key worry associated with your current/planned heating systems?

 

[Peely]

thanks for your response, this is a example of the response we received..

"I've received responses from all my insurers, and unfortunately, we cannot cover this risk. The presence of the tin roof over the thatch is a significant factor. While we used to cover this, our underwriters have since revised their criteria."

the CO has suggest she would prefer us to remove the tin and the thatch and if we didn't / couldn't go for Thatch replace the tin, saying that someone in the future could put it back to thatch. I get that however according to our builder as tin sweats there needs to be a roof under the tin, and according to the structural engineer the existing structure can't cope with that so we would need the roof over the roof anyway.. the result is the quote we have is pretty much the same for Temp Tin roof vs Slate.

 

[Cubist]

I don't know who your brokers may be but Lloyd and White have been more helpful than some for me and others. They may be worth a call.

Regarding your builders comments regarding 'tin sweating'. That's not exactly true. Yes, water can and does condense out of the moisture laden warm/hot air onto the underside of the tin and this can lead to problems for the timber structure of the roof. However, breathable membranes can be positioned over the timbers to isolate them from the tin/iron to mitigate this risk. Similar membranes would have to be installed for any other alternate roofing material, including thatch - but the latter would also need a fire retardant membrane of some kind instead or as well.