a couple of questions about a kitchen.

[Penners]

Flyfisher has made a number of sensible points about your asbestos roof. So long as it's not drilled, sawn or otherwise persuaded to turn into dust, it shouldn't be dangerous. Painting it with an oil paint would improve its safety.

But if you're firm about replacing it, firstly you should consider the dangers inherent in removing the sheets. This could create dust, and it's therefore sensible to call in specialists for the job.

As regards your choice of a replacement roof, once again I agree with FF - pantiles could end up with little or no pitch, due to their overlap cant. But why not try laying a few on top of the existing roof to see?

The minimum pitch for slates seems to vary according to the size of slate, the headlap, and various other factors. But a rule-of-thumb suggests that any slate roof pitched at less than 25 degrees should be generously headlapped and well provided with a second line of defence (ie: membrane), and it's probably unwise to attempt anything less than 20 degrees.

Unless your floor has a lot of bricks in consierably better condition than those that you've shown us, I have my doubts whether it's rescuable. But I hope I'm wrong. However, if you need to, you can find all kinds of pamments and/or brick paviors in most reclamation yards*, or go and see Bulmer Brick & Tile, in Bulmer, near Sudbury, who make new ones.

As Graham has said, that clay lump wall looks as though it's crying out for lime plastering. Whatever you do, don't get any gypsum or cement anywhere near it.

* Be sure to choose a yard that subscribes to the Salvo code.

 

[Jon Maine]

With regard to the roof.

To remove asbestos you can seal with diluted pva which if sprayed or brushed on will stick down any loose fibres.

Corrugated iron is a traditional material in this sort of use and is a worthy one to use. It would need to be well insulated underneath with both sound proofing and thermal insulation and a vapour barrier. The problem would be the finish, bright new galvanised may be to bright although it could be etched and painted.

If you go to a tiled roof or slated roof the pitch is far to low for both so you would have to be a bit ingenious with your design. If you decked the roof with plywood and felted it like a flat roof you could then stick counter battens up the slope of the roof bedding them in mastic. Then felt and batten over this to lay your tiles. By giving yourself a fully waterproof structure under the tiles it will help deal with the shallow pitch and leakage through the head lap. It will give you an interesting detail to sort out at the eaves because you have two different levels which need to run into the gutter. It is a lot of grief but can work well. Don't try to slate or tile it without a secondary system or you will have problems and probably quite rapidly.

Of course you could also use lead sheeting, zinc sheeting or copper sheeting too.
http://www.jtcroofing.co.uk/zinc_roofing.cfm
If you go for any sort of sheet metal roof it needs to be installed on a geo textile membrane which allows it to expand and contract and slide a little. Certainly with lead it is only fixed upon the top third so the bottom two thirds can move otherwise it can pull itself to pieces fairly rapidly.

Food for though for you.

 

[Penners]

Of course you could also use lead sheeting, zinc sheeting or copper sheeting too.

Ooh - brilliant idea! Wouldn't copper look great?

 

[robgil]

thanks guys , all food for thought there. i have thought about a copper roof and although they do look fabulous it might not look too good attached to the rear of a 16c cottage. i dont know though , it could turn out fantastic and at the same time it could turn out looking really out of place. tin would be an easy alternative and could be etch primed and painted as Jon stated but being relatively large and flat would it be noisy in heavy rain?
putting a felt roof under slate sounds like a good idea and also a lot of work. decisions decisions.
would it be a good idea to run all these ideas by a building inspector first perhaps to see what exactly would be required to make them adhere to building regs?

 

[Flyfisher]

I suspect that building control would have something to say about the thermal performance of a new roof, which is no bad thing in itself but might possibly give you a problem given close proximity of the lean-to roof to the existing thatch - i.e. you have a limit on the thickness of the lean-to roof. I think that once you involve BC you will have to comply with whatever they specify.

Part of our roof covers some attic rooms and we decided on a 'warm roof' construction; plywood/insulation/counter-batten/breathable felt/battens/tiles. You could, perhaps, consider something similar, except that you chould choose a different final layer to our pantiles - the key points being that the felt will provide a waterproof layer, the insulation will retain heat and the outer layer will be mainly cosmetic.

This is similar to Jon's suggestion and I can assure you that it's not really a lot of work. In my experience most of the work goes into the preparation and any necessary repairs. Once you have a 'clean' roof structure, felting and battening doesn't take too long at all. In fact, it's the rewarding part of the job because one seems to make little or no real progress for ages but can then felt and batten an entire roof in a single day, or two. Certainly no more than a day for your lean-to.

 

[robgil]

you know i am reading 'the old house handbook' by 'roger hunt & marianne suhr' and although it doesn't go into great detail (but it covers a lot of different topics) about pantiles its states,
' since the overlap is smaller than with plain tiles fewer are required , so the weight of the roof is less. the interlocking fit means that pantiles can be laid to a lower pitch ; they are therefore used extensively for lean-to extensions'.
another spanner in the works , just as i was going off them in favour for some nice hand made peg clay tiles (although i would probably use nails).

it also talks about wooden shingles , are shingles a common thing on period property's in the suffolk area? they look fabulous and would really work with the thatch nicely.

edit - they seem to have a very low environmental impact as well which is good even with the low life expectancy.

http://www.greenspec.co.uk/html/materials/pitchedroofs.html

 

[Flyfisher]

But there are lean-tos and lean-tos. Do they mention a minimum roof angle for pantiles? It's certainly true that pantiles have a small overlap and should therefore be lighter than 'standard' tiles, but any tiles will be heavier than your existing corrugated sheets, so that's your starting point.

But it would probably be fairly simple to add additional rafters to strengthen the roof to support tiles and, as previously mentioned, as long as you have a waterproof membrane under any tiles, then the shallow pitch shouldn't be a big problem.

 

[Jon Maine]

I must emphasise that your pitch is to low for any period acceptable tile to work properly and not leak into the substructure. I can promise you I have far more experience than Marianne on roofs!( not sure about Roger Hunt though! ).

 

[JoceAndChris]

Is it too late to say, why aren't you learning to thatch? A little thatch there would be sooooo cute!

 

[robgil]

so we can safely conclude that whatever i use unless corrugated sheeting or felt i am going to need to use a felt underlay. this is fine and i would certainly rather that than a leaking roof or the roof as is.
what are your thoughts on shingles then guys?

i thought about thatching it but it would only rot prematurely due to the shallow pitch and i dont want to confuse future owners by tying it into the existing thatched roof.

edit - i would love to learn to thatch though , what a fantastic job (in the summer time).

 

[Jon Maine]

Almost any ( if not all ) sheet material would be fine at that pitch, tiles would need a properly waterproof felt layer more than usual felt and batten. As for thatch I am afraid I cant technically advise although I suspect it would be far to low, on a conservation point of view probably best use a sympathetic material in contrast to the thatch to outline the new 'quality' work.

 

[Ushy M]

Is it too late to say, why aren't you learning to thatch? A little thatch there would be sooooo cute!

Joce, it would indeed look v. cute, but as others have pointed out, the pitch is too shallow for a "mini-thatch" - thatch works by shedding water very quickly - hence the steep pitch you usually see on a thatched building.

Robgil - our neighbours, whose roof and extension you can just see in the pic I posted have wood shingles on their extension. They are starting to show their age and curl up at the edges somewhat (the shingles that is - not the neighbours :wink: ). I'll ask them what the total method construction was and if they've been happy (and watertight). As you can see, the pitch of the roof is similar. Our tiles were already on, so we had to do a like for like repair, or I'd have been tempted by shingles too - I think they look really sympathetic with the thatch.

 

[Jon Maine]

I have had difficulty finding specs on shakes and shingles but so far can say shakes should apparently not be laid on a roof which rises less than 5 units for every 12 horizontal units. This would appear to be 22.62 degrees.

The more exposed to driving weather the more likely to failure. You could install on lower pitches but at your peril......

Life expectancy 20 to 40 years.

I will check my books too.

 

[robgil]

ushy that would be most helpful , thank you.
i have found this http://www.fao.org/docrep/S1250E/S1250E0l.htm and it states that shingles do need more of an elevation than that of this roof. looks like i will need that felt underlay afterall if i use shingles but thats still doable though eh?

 

[worms]

I would be surprised if shingles on a low elevation would last very long. If you are relying on the membrane to shed some of the water, some of dampness under the shingles will surely be retained in the shingle and they will rot from underneath?

 

[Jon Maine]

I would tend to agree with that theory worms

Of course you could use corrugated sheet and then screw down through the ridges to fix roofing battens to form a waterproof sub structure.

 

[robgil]

this looks interesting guys , page 15 second diagram down.

http://www.johnbrash.co.uk/downloads/cms/Shingle%20Specification%20%20Brochure.pdf

they use felt as a kind of secondary shingle underneath each line of shingles.
so basically its like felt shingles which are very good at low pitches and still very waterproof except they have thrown in wooden shingles as well.

 

[Ushy M]

Robgil, I asked our neighbours about their shingled extension roof. Apparently, this roof covering was already on when they bought the house and looked as if it had been there for some time, so we're guessing it's been on there for about 20 years.The shingles are laid on a waterproof membrane and haven't had any maintenance or repair during this time. Neighbours report they're warm and watertight. I've taken a picture (by hanging out of our bathroom window :shock: ) so you can see better. Hope this helps.

 

[robgil]

you have helped enormously , thank you. according to this http://www.johnbrash.co.uk/downloads/cms/Shingle%20Specification%20%20Brochure.pdf i can go down to 14 degrees so hopefully shingles it is.
i will need planning permission for this wont i?

 

[Ushy M]

i will need planning permission for this wont i?

Can't help on that I'm afraid - my understanding is that as Nigel Watts has suggested in the 'Our House' thread, the process for conservation areas isn't the same as for LBC or planning permission. I'm sure someone who knows will be along soon - have you looked on your local council's website? They're sometimes pretty helpful on what permissions are needed for what.