DIY New Roof - Good Idea/Bad Idea - Brave or Stupid?

[AndrewSchofield]

We have been considering converting our loft for some time now and i've finally completed the detailed drawings and obtained Building Regulation full plans approval on them. I've asked a few builders to quote for stripping the roof, replacing the rafters and constructing a timber framed dormer with uPVC cladding and re-laying the slates and the prices i've got back were quite a bit more than i had expected which led me to start thinking about doing the work myself. I would say i'm a fairly competent DIYer and intend to do the internal work myself anyway - new floors, new internal walls, new staircases etc..... and being an Architectural Consultant i have some knowledge of how the thing will be constructed although i lack the physical experience.

My main worry is the house being exposed to the weather while i do the work and a couple of things i'm unsure of (flashing around the chimney, felt flat roof over the new dormer). I am under no illusions that it'll be easy and realise it'll probably take me longer to do than someone with experience. From a personal point of view i'd love to tackle it and to have that sense of acheivement when its all done that i did it myself. Guess i'm a bit nervous about doing something on this scale for the first time and about what i do if things go wrong!!

Does anyone have any opinions on whether its wise to tackle this sort of thing or whether i should lie back and let the experts get on with it. I figure that people on a DIY forum will tell me honestly whether i'm stark raving mad or encourage me to give it a go?!?

 

[noseall]

you could start by enclosing the whole 'project' within a canopy scaffold

at least this will keep the weather out.

logistically though, these are the most difficult of jobs.

also, you might find yourself buying a stack of expensive tools only to be used once (one project only).

there will be a lot of measuring and it will be on your head and wallet if things are measured wrong. measure twice - cut once.

 

[AndrewSchofield]

Thank you noseall - to be honest i'm glad you replied as i've seen your posts all over the forums and you seem to speak a lot of sense!

I do have a lot of hand power tools already although i'm not saying i wouldn't maybe need to buy some more. That said, the amount i save on builders cost should easily cover the cost of tools and i could maybe sell them on if they prove to be useless later?

One of the builders i've had price off has suggested he'll use a canopy scaffold anyway so that may well be the best option.

I have heard and do obey the 'measure twice, cut once' mantra - did work experience with a joiner years back and one of my mates is a carpenter so understand the importance of this. To be honest, i'm a bit of a perfectionist so i'll probably be mesauring things to the mm and thats why i know it'll take me a while to do! I also give things i'm doing 'a few doses of thinking' before jumping in, hence my caution at starting it myself!

 

[noseall]

echoing what you have already said - the one thing that may get you down is your speed. your lack of confidence and/or experience, may cause the job to drag on a little.

this could be a nuisance should you wish to go on holiday whilst the house is 'un-secure'.

getting some builders merchants to take you seriously can also be a problem, so learn the lingo. better to sound like a builder.....!

 

[AndrewSchofield]

Materials aint a problem as i've got a contact through work who is getting me a good deal on a lot of things i need and i've already spoken to someone at a local builder's merchants and used my work e-mail signature to sound like i'm in the know to source the things he can't supply! To be honest i was thinking of getting builders to quote labour only and sort the materials myself.

Suppose then its a case of weighing up cost against time??

That is one thing that worries me actually, whether i do the work or not - is there a way to secure the house as a house with no roof and scaffolding up the side sounds like a 'come and help yourself' cry to theives? I'd like to think we live in a village where this wont be an issue but also realise that there is a rouge element almost everywhere these days.

 

[noseall]

i am always aware that a house is vulnerable once at the 'roof off' stage.

i am also never surprised to find all the belongings still crammed below the area we need to remove!

there are easier and less conspicuous ways to remove belongings than down a ladder, but nevertheless, it still makes me cringe to think how easy it would be to enter someones property.

bolting the loft hatch is about the best you can do. we always remove the ladder in the evenings or clip a scaffold board to the ladder bottom.

 

[AndrewSchofield]

Fastening down loft hatch seems like a sensible precaution. And i totally understand the loft full of belongings comment - we've spent the last three weekends emptying ours - why do us humans hoard junk in such high quantity!! Maybe it would have been an idea to bolt up the loft hatch 10 years ago and then maybe we'd have thrown some of it away!!!

 

[vinty]

If your going to have a flat roof on your dormer and you intend to have a go at covering it yourself, you should think of using single ply membrane system, as torch on felting can be dangerous also your insurance may not cover you.
In my experiance butyl, or E.P.D.M. RUBBER is the easist to fit, if your dormer roof is a simple construction with no awkward details or projections then it is only a matter of measuring the length and breadth of your deck allowing extra around the edges and up the layboard, you then get it cut as one sheet, you then can fit it by two methods one is fully adhere it with adhesive, or ballast it with roofing pebbles

 

[AndrewSchofield]

vinty,

Thanks for the advice. I know my limitations don't worry and wandering about on the roof with a torch is beyond me without a doubt!!! The roof is pretty much square apart from one of the corners where it wraps around the chimney slightly. It will be about 4.8m wide and 2.8m from where it meets the roof slates to the 'eaves'. Can you get these sheets cut to this kind of size? There is a guy down the road who does lead work and is pretty good at it by all accounts so was thinking it'd be worth getting him to quote for finsihing it with lead?

Just out of my own personal interest, anyone know what EDPM stands for?

How does this stand up over time then, will it last as long as felt and do i need to protect it from sunlight to stop it deteriorating? What kind of on-going maintenance will it need?

 

[vinty]

E.P.D.M. OR E.D.P.M., or what ever it is called is a very long chemical name. Firestones manufacture it, they have an office and training centre in cheshire, they also have a web site, i did a course with them it was only 2 days.

As for fitting it , on a simple roof like you have described it is pretty straight forward. Basically it comes made to measure, i think the simpliest method in your case would be to ballast it, the hardest part of this system is carrying the bags of roofing pebbles onto the roof.

As i have said before measure your roof LxB allow extra all round your roof for the drips over the edges into your gutter ect. include your layboard where your flat roof meets your tiled roof, allow plenty extra because you can trim it of with scissors when you are finished.
you can phone your supplier and give them the dimensions they will then cut it and send it to you, it's like a rubber tarpaulin really.
If you ballast you have to put an underlay underneath it this is to prevent sharp edges. To be continued.

 

[AndrewSchofield]

Done a bit of research into it and found a company who supply the stuff for DIY although they do have a fitting service too - they advise that its so easy to use anyone with a bit of practical nouse should be able to do it themselves. Looks like it may well be the best option for me - they advertise that it should be waterproof for 50 years and is guaranteed for 20, isn't affected by exteremes of heat or cold and does degrade under UV light so all sounds good (this assuming this isn't just a good sales pitch?)

Thank you for bringing it to my attention.

If anyone else has any experience of using it i'd be grateful to hear any good/bad comments on it?

 

[vinty]

Is the rubber you are buying is it butyl or epdm. The reason i ask is that butyl is mostly used as a pond liner, it can be and is used as a single ply roofing membrane, the problem is it can't 'breath'this can cause condensation on you deck which causes it to rot in a short space of time.

I have experience of this problem myself, i stripped the membrane from a dormer roof, the deck which was 18mm exterior ply had completely rotted away the butyl sheet was absolutly soaking under neath. If butyl is to but used were there is heat risin g from the room below, insulation has to be used.
E.P.D.M membrane is vapour permeable , which means moisture passes through the sheet but doesn't allow rain water to ingress. E.P.D.M. also has a BBA. certificate which confirms this. Good luck.

 

[AndrewSchofield]

These are the company i've found so far it seems to definately be the EPDM not the Butyl.

http://www.rubbershield.co.uk

 

[vinty]

These are the company i've found so far it seems to definately be the EPDM not the Butyl.

http://www.rubbershield.co.uk

That site gives a good illustration of how it is fitted, if you need any more information about epdm you can contact firestones the manufacturers direct, they have an office outside liverpool their technical officer is called Carl Bailey he deals with the public and contractors enquiries, their tel. no is on their web site.
P.S. just one last point if you ballast your roof make sure that your joists and deck will carry the weight as ballsat is very heavy.