Warmroof

WE need cold roof ere mate.

If you mean warmroof then I'd say it sounds like a horrible nasty bodge and wouldn't go anywhere near it with a barge-pole borrowed from someone else just for the occasion. And this chap seems to think so too: http://www.ask-jeff.co.uk/building-roof-repairs.htm

I'd also be rather concerned what a buyer's surveyor might say about it if you ever want to sell the house.

Rooves are built the way they are for a reason, surely if this was a better way of doing things then all new houses would be built with this stuff under the tiles?

Steve.

Yes i'd seen that article - I must admit to having serious doubts about warmroof - and despite having paid a £250 deposit I'm getting a second opinion from a regular roofing company (through my manager) before I go ahead with warmroof - I have to admit to having been somewhat hasty on this, but would rather lose £250 than continue throwing money at something I'm not too sure about

Can you get a Local Authority Grant to part fund re-tiling the roof ?

Might well be best in the long run ......

Fisbey

I would have the roof seen to by a builder - get a few over (preferably by recoomendation from friends & relations in your area) and see what they have to say.

Mike

To be technical for a moment:
Insulation within any roof space will create a "dew point" where condensation will form, and this can be above the insulation or within it, depending on the temperature difference inside and out and the insulation qualities of the material used. In old roofs using insulation quilt on the ceiling joists, the condensation formed was considered to be within the roof space itself and this is why roof spaces were ventilated; to get rid of the moist air. Sometimes you can see the effects of condensation of the underside of the rafters as a white staining, usually a sign that the ventilation is inadequate. In extreme cases, rot will begin and the rafters become dilapidated. This is why insulation quilt needs to be kept back from the eaves, to allow air flow and stop dry rot. Now, we generally use a warm roof construction where the insulation is put between the rafters. This can also be done to an old style roof, but a 50mm air ventilation gap is needed between the insulation and the underside of the roofing felt, with ventilators at the eaves and ridge, to get rid of the moist air - so it isn't really a warm roof but still a cold roof. With me so far?
Modern construction allows the insulation to fully fill the gap between the rafters with no ventilation space, but this is because the roofing felt used is breathable!! and allows the moist air to pass through and condensate on the outside of the roof space on the underside of the tiles. This spray on stuff completely ignores the placement of the dew point and could cause dry rot in the rafters as moist air may get trapped and constantly generated almost anywhere. If you re-tiled the roof and replaced the felt with a breathable felt like Tyvec, you would be OK, but the insulation would itself need to be breathable.
This company may have an answer to the problem, but I would need to see evidence of their calculations to illustrate how they manage the condensation.
Well...........you did ask!
Oh....and don't ask a builder, ask a professional!

I've cancelled the credit agreement and written to warmroof asking for my deposit back (worth a try I think)...

Thanks for all your responses - confirmed what I was feeling really....

Time to get a (professional) roof person round....

Rasher - is building/roofing your trade?

I'm a Structural Engineer, and I was also an associate in an Architectural practice for 10 years

Fisby. You said that this was all because you started out with a leaky roof. This spray on stuff sticks like shit to a blanket, and if your roof leaked still, the only cure would be to re-tile which would almost certainly end up with you replacing the battens and roofing felt. Most of your new spray-on stuff would end up coming out with the felt, so you would have spent loads and ended up with it all in the skip. If you have a leaky roof, address the leak. I wish I was nearer.
How is it leaking? Is it an open roof space or is it to a room? Is the felt torn? Any dislodged tiles? Is it coming in at the sides?
If I didn't know a good trustworthy local roofing firm, I would phone your Building Control office, ask to speak to a senior officer, and ask unofficially for a name.
Good luck buddy.

Thanks Rasher - the leak (s) is not obvious - but one can see daylight where the tiles have 'lifted' and some are more obviously missing. The roof battens are wet as are the main uprights only less so. The render over the chimney breast is flaking off, and bits of carpet and loft insulation are damp to the touch. The whole are is covered with black dust and needless to say very cold. It is used as a storage room only, but I suspect the situation is none too good for ones health....

I will have 'proper' roofer look at it over the weekend and hopefully get it sorted soon, as it will only get worse....

Thanks again.

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Time to get a (professional) roof person round.... FISBEY

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That is your best bet!

Proper "warmroof" construction on a new roof is done by fixing the insulation to the outside of the roof - phenolic foam boards are fixed directly to the rafters and covered with a breathable felt, the roof covering is fixed on top in the traditional method. This is accepted by building regs, but there are still problems...(see below)

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Modern construction allows the insulation to fully fill the gap between the rafters with no ventilation space, but this is because the roofing felt used is breathable!! and allows the moist air to pass through and condensate on the outside of the roof space on the underside of the tiles. Rasher

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There are mixed views on this, a lot of slate/tile suppliers, will argue that condensation gathering on the underside of slates/tiles will eventually ruin them, due to the water freezing.

The other problem I see with this "spray on foam by warmroof", is that it locks the slates/tiles together as one piece, this can't be good? If you experience high winds, there is a danger that instead of loosing a few slates/tiles, the whole roof covering could lift! Roof coverings are designed as hundreds of small pieces to avoid such a senario...

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Oh....and don't ask a builder, ask a professional! Rasher

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I'll second that. Your local council building inspector might be a good place to start, he will also know if it's possible to get a grant for the work...

IMO there's no substitute to proper tradition tried and tested roof construction, don't cut corners, your entire house and contents are protected by it!

Traditional tried and tested roof construction unfortunately doesn't apply anymore. We have to deal such high levels of insulation that the problems of condensation have to be dealt with and traditional solutions just don't cut it. That has forced new methods that are unavoidable, and these present a whole new set of problems that have to be addressed. Old traditional building isn't acceptable under current Building Regulations. The new regulation for windows and glazing comes in April, which will probably force triple glazing. In 5 years there will be new regulations to provide air through buildings in order to allow us to breathe. Did you know that ALL new houses now require a disabled toilet on the ground floor and a ramped access?

Rasher,

Going slightly O/T here,but... if I bought a Victorian house, where some heathen had previously fitted upvc double-glazing, is there any way I could revert to wooden sash windows and still stay within the current (and/or impending) regs? Ans what if it had the original, but rather worn and tired wooden sash windows?

Would the regs force the owner to go down the plastic route? Or are there ways around it for houses which are historic enough to look wrong with plastic windows, but aren't special enough to be listed?

Steve.

Traditional construction using modern insulation

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Old traditional building isn't acceptable under current Building Regulations.

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Yes it is, especially when dealing with traditional buildings...

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The new regulation for windows and glazing comes in April, which will probably force triple glazing.

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Don't know about that, but it wouldn't suprise me. Imposing higher U values on new builds, isn't going to stop Global warming.

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In 5 years there will be new regulations to provide air through buildings in order to allow us to breathe.

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New? maybe. The current regs do provide for this though (trickle vents etc). Mind you our local newly constructed council offices suffer from sick building syndrome, due to bad/new design.

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Did you know that ALL new houses now require a disabled toilet on the ground floor and a ramped access?

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Yes, I knew that cos when the buildings inspector finally passed the barn I converted, he said I was lucky to have just missed that law...

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Originally posted by Steve Bull:
Rasher,

Going slightly O/T here,but... if I bought a Victorian house, where some heathen had previously fitted upvc double-glazing, is there any way I could revert to wooden sash windows and still stay within the current (and/or impending) regs? Ans what if it had the original, but rather worn and tired wooden sash windows?

Would the regs force the owner to go down the plastic route? Or are there ways around it for houses which are historic enough to look wrong with plastic windows, but aren't special enough to be listed?

Steve.

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Only an unqualified opinion but I would have thought you could fit secondary glazing within the sash windows. I've lived with vertical sashes for decades and they are almost impossible to keep airtight. So bad infact that secondary glazing is very unlikely to "steam up".
An alternative would be to get handmade, wooden windows with "energy" glass glazed sashes and then (greatly) increase the balance weights in the frames. You might need to use chains though instead of sash cords.
You'd need quality brushes or bronze seals or some other accepted sealing method to reduce air exchange around the edges of the sliding sashes.

Find out what they do in Bath to their Georgian listed buildings. Most of those have vertical sashes. So there must be a way round the problem.

Nime

Rasher
What was the older version of this - applied on top and something like sacking and tar. Same sort of bodge with similar problems.

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Originally posted by Barnie:

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Old traditional building isn't acceptable under current Building Regulations.

Yes it is, especially when dealing with traditional buildings...

How do you define "old traditional" then? You could make it look traditional, but that isn't traditional. Strictly speaking of course.
Steve; I don't know about the windows yet. There is no way you will be forced to use materials that would change the look of the house. I'm not sure how that will turn out, but it is a massive problem for traditional carpenters making timber sashes, which is criminal IMO. Most punters will just go the easy route and put in plastic, which I think is a disaster. Most Building Control officers don't know themselves yet how to approach it, and thankfully most are pragmatic and will find a way to satisfy the regs by some sort of trade-off and pass the information on.
What is this? Rasher's handy home DIY page or something?

I guess you work in building contol?

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Originally posted by Rasher:
How do you define "old traditional" then?

Well in the case of roofs - A proper cut roof, instead of those horrible trussed roofs using matchsticks and nail plates.

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You could make it look traditional, but that isn't traditional. Strictly speaking of course.

You could, as I did, build an "old traditional" roof by using "traditional" methods... A frame construction, employing tusk tennon pegged joints to the purlins. Of course, building control will insist on structual calculations and stress graded timber, but it is, strictly speaking "traditional"

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Steve; I don't know about the windows yet. There is no way you will be forced to use materials that would change the look of the house. I'm not sure how that will turn out, but it is a massive problem for traditional carpenters making timber sashes, which is criminal IMO. Most punters will just go the easy route and put in plastic, which I think is a disaster. Most Building Control officers don't know themselves yet how to approach it, and thankfully most are pragmatic and will find a way to satisfy the regs by some sort of trade-off and pass the information on.

I can imagine the "trade offs" - Planning officer says - you cannot put plastic windows in that building - Building inspector says - but the regs call for triple glazing - Planning officer says - well make them use double glazing and up the U values in other areas of the house......

BTW The building inspectors I've dealt with, have been immensely helpful and nice people, just incase you get the wrong impression

What aspect of the new regs will force "triple glazing"?

quote:

Originally posted by Barnie:
You could, as I did, build an "old traditional" roof by using "traditional" methods... A frame construction, employing tusk tennon pegged joints to the purlins. Of course, building control will insist on structual calculations and stress graded timber, but it is, strictly speaking "traditional"

I hope you brought the materials in by horse & cart and wore green corduroy breeches with braces and a straw hat.

This is the change that forced control on windows, and this is the boring bit. There is a bit in there for calculating the efficiency of the gaps around the window to stop air flow!!!!!

Well I did comply with the braces and straw hat

Thanks for the links.

I don't think "triple glazing" will be mandatory. Did you know that a south facing window, using a timber frame and double glazing with an 18mm air gap and L glass, will result in zero energy loss?

I think the new regs with regards to registered installers, is going to give the dodgy DG companies a license to print money. I mean it's easy to comply with regs, but quality of workmanship is the key to success, which seems to be largely unregulated...

Fisbey,
If you're within reasonable distance of Teddington, I can suggest a good roofer you could talk to. He re-slated my roof 3 years ago and did an excellent job. Finding a decent roofer you can trust isn't easy! If I can help, email me (david at impactron dot co dot uk).

OK Thanks David - I'm in Stanwell. I have someone (recommended by my boss) coming over on Saturday, if that doesn't work out I'll drop you a line.

I was up in our roof on Sunday trying to sort out the arial (I gave up and got SKY instead)

Up there is a layer of straw.

Bring it on!

Nowt wrong with staw, unless your under the restictions of fire regs.... Even your cob walls have staw in them, oh and some cow shit!