Advice on insulating hipped roof please?

[kirstent]

Hi all,
We are having a 2 storey side extension (5.1 x 3.7m) on a 1940's ex-council semi with hipped slate roof. Extension will have new hipped roof to hipped roof. Existing roof is backfilled which is all dropping off, slates and ridge tiles starting to slip and needs sorting so we are having it stripped, felted and relaid, sourcing reclaimed slate, all being done at the same time. We have arranged own scaff which is up.

Untitled

• kirstent
• 23 Jun 2012
• 1

Sorry for poor quality image - only jpeg plan is this one.
Joiner and roofer been to see us, liked them, quoted as follows:
- Joiner - fit new trusses to extension plus fascias, sofits, guttering whole house BEFORE SLATING (labour only) - £800 + VAT
- Roofer - strip, felt and relay existing and new slates, including battens and lead - £2k + VAT
- Truss quote - £500 + VAT
- UPVC SFG quote - £300 + VAT
We can get slates for about £1.40 each
This all adds up to £4.2k + VAT for new roof and reroof.

My questions if you could poss help are:
1. Seem fair prices? Joiner seems good value and truss and UPVC quotes seem good, not sure about £2k for roofing labour tho.
2. Joiner wants to fit trusses then UPVC before slating so that "there is a line for the roofer to go to with the fascias being there". We don't want UPVC up there before roofing and extension finished - it'll get damaged. Plus the roofer needs to go off the existing lines as it's a semi or it won't match the neighbours surely?
3. Anyone keen on Ubiflex instead of lead? That might help nip the price down.
4. This is a raised/dropped collar roof? (The bedroom ceilings slope and we have roof beams in the corners of the rooms). This gives us dreadful cold bridging/mildew/condensation issues and we MUST address this while the roof is off. How can we insulate the new roof adequately to stop these problem areas happening again. We have cavity wall insulation and will be renewing loft insulation and having eaves vents I believe. How do we keep roof space ventilated but insulated? Giving us headaches.

Thanks so much in advance for any replies. I'm not trying to insinuate the roofer and joiner are overcharging us. We are short on time and money, doing a lot of it ourselves, with 2 little uns and believe it or not are struggling to get quotes for the roofing part although there are joiners willing to quote labour only. The brickwork will be finished mid next week and we need to decide whether to just crack on or keep pursuing other quotes. Incidentally, we've got a really nice guy coming measuring roof up for us for free, he measures for most of the timber people round here so said he would get a fee back off them at some point in the future if we didn't go with one of them this time - what a star!

Cheers!
Kirsten

 

[freddiemercurystwin]

Sounds cheap as chips, I'd be wary of it sounding too good to be true tbh!

 

[^woody^]

We don't want UPVC up there before roofing and extension finished - it'll get damaged.

No, don't think like that

The facsias, soffits and gutters should go up before membrane and tiles so that the eaves tray and tiles are set to the gutters.

It wont be damaged

Ubiflex is OK, but is it that much cheaper than lead? If no use lead

Your designer should have specified how to insulate the rafters at ceiling level. You'll need insulation between and under the slope

 

[kirstent]

Thanks chaps,

I can see that the price looks pretty good when compared to the £4.5kish that people seem to be paying just for a reroof - I look tight now. A friend was meant to be doing the roof for us and it would've been £2k all in so budget is very squeezed now that he can't do it.

woody (where do you find those arrows round your username on the keyboard?) thanks. UPVC makes sense now. Our designer is my brother-in-law who drew up and specd what we gave him (architectural technician but not architect). Loft insulation specd but nothing about that area around eaves (existing dragon tie?) - they now have a brand new baby so think our favours are all used up.
Ubiflex looked to be about £100, with lead £200? Only £100 I know, but that's 4 Ikea dining chairs in my budget!

Thanks again for your responses - v much appreciated.
Kirsten

 

[noseall]

The upvc fascia need not go on if you go with the fascia cap method.

This involves fitting the timber carcassing fascia first, which will deal with the tile rest and eaves tray detail, then the fascia cap can go on later.

All the roofer need do is allow an extra say 15mm on his overhang.

 

[noseall]

Are you looking for these ^^^^^ arrows?

 

[kirstent]

Oooh that's an idea, thanks noseall. OK, don't rub it in about the elusive arrows - I obv have rubbish keyboard - still can't see the little swines....

 

[kirstent]

OK, sorry for adding again, but just been up the scaffolding debating and looking.
The other problem with having gutters up now is that the downspouts will be in new locations and the drains aren't ready. Because we can't be certain exactly where they will be till the chamber is in the ground and BC are happy, then we can't fix guttering and downspouts. Basically we aren't ready for gutters yet so do they really, really have to go on or is it more the case that it makes life easier for the roofer if they are there. Is it sufficient to only have fascia on (or fascia cap if going with noseall's suggestion) - we could live with that, plus at least any rain would evenly flood us, rather than flooding a specific undrained area.

Can't we use a string line? Next door have new UPVC fascias, gutters etc (it's actually what my neighbour used to do for a living) and we'll be matching in with them so is that line not enough to go on?

This is definitely the trickiest bit we've had to deal with. This is the problem when you do a lot yourselves I suppose.
Thanks v much
Kirsten

 

[noseall]

Guttering will be fitted after the roof tiler has finished.

You will need to assume where the rainwater gullies will be best positioned and then fix your outlets and downpipes accordingly. Fix all guttering prior to removing scaffold. We usually fix it having removed the top scaffold lift, as it is easier to reach up than to crouch down.

As far as the soffit and fascia detail is concerned then yes, it all needs to ultimately line up with the existing if these are in plane. Measure the overhang, timber fascia thickness, upvc fascia thickness and work back to the rafter ends, trimming accordingly.

The soffit boards are supported on timber cradling that is fixed to the rafter ends. The fascia is usually fixed directly into a trimmed rafter end.

The actual depth of the fascia is dictated by existing fascia. Or you choose a depth that provides enough 'kick' for the first course of tiles and collects the soffit.

 

[theoldun]

A lot more information would be required to be specific so can only generalise in the order posted.
Carpenter, labour only £800. to birds mouth and fix raised tie trusses, girder truss, reducing valley trusses, loose hip construction, wind bracing, lateral bracing, facia and soffit is a reasonable price. However check that he is VAT registered and has VAT number, as most labour only boys are under the Vat threshold in what they earn.

Roofer,. labour only at £2k is a fair price especially if he is supplying lead, battens and Tyvek breathable felt or similar. Check that he is supplying breathable felt, as it is not cheap. Suggest GRP valley instead of lead or Ubiflex
Truss price £500 plus all loose unfill as detailed above is about right.
UVPC near enough.
Slates depending on size, sound touch high, but then again, do not know your part of the county.
Always fit facia and soffit before tiling. You have got to work hard to do any damage.
Always fix gutters and down pipes after roof tiling completed. If you have no drainage in, take down pipes down to below DPC and let them run on garden or drive until drainage in. With permeable felt such as Tyvek, no ventilation required to roof space.
This is a raised/dropped collar roof. No it is a raised tie construction. In the new build, insulate from below raised tie before tacking ceiling. In the old build insulate raised tie as soon as roofers stripped of slates and battens. Use either 300nn fibreglass or 100mm GA4000 Celotex. You can either insulate remainder of ceiling before tacking or after tacking. Cut some battens out below the fly over to gain access.
Repeat. Facia and soffit before roofer. Gutters and down pipes after roofer finished and before scaffold down. Do not know what some one is coming round to measure roof for if you are using trusses. You only need wall plates.
Regards oldun

 

[^woody^]

It is a whole lot of messing about trying to fit and align gutters after the tiles and eaves tray are fitted. Apart from the difficulty it can lead to poor fixing and misalignment - not just of the gutter but the tiles and tray too

So it is always better to fit it first, along with any plastic capping fascia.

I see more mistakes with post-fitted gutters. I'd only accept gutters fitted afterwards if I was confident of the builder/roofer's ability to do it right

 

[noseall]

So it is always better to fit it first, along with any plastic capping fascia.

No it is not.

Fitting guttering and fascia cap prior to roofing tiles is insane as well as being a hindrance and something to muck up whilst cutting billions of tiles.

Woodcarver, you are wrong here.

So long as you have the timber fascia carcassing all other bits can be measured off the carcass fascia. Not at all difficult, not rocket either.

Woodchop, you must work with some dodgy builders...

 

[noseall]

It is a whole lot of messing about trying to fit and align gutters after the tiles and eaves tray are fitted. Apart from the difficulty it can lead to poor fixing and misalignment - not just of the gutter but the tiles and tray too

Can you explain this bit please Woodblock as i am baffled??

 

[^woody^]

It's OK saying that this can all be measured if the bits are on site. That relies on the roofers bothering or remembering to do this.

So you can end up with situations where the plastic eaves tray has been fitted and not allowed for the plastic fascia or the width of the gutter clip. So the clips don't fit where they should

Then you can get tiles not overhanging for the correct gutter profile

Then you can get the plumber not being able to fit the gutter clips properly under the eaves tray and tiles. Then you get the gutter too low or on a stupid fall because the gutter is fitted below the tiles and plastic tray for "ease"

Your sounding like oldun with this "that is wrong" business. There are lots of ways to achieve an end result

It's all about risk management of the final job. Any method is OK as long as the resulting quality is achieved. If I know that a particular firm will do the job right, then that's OK and they can get on with it their way.

If I have any doubt, then I will remove that doubt (that risk), by specifying how they should do it. And that is to fit the fascia and gutter first - then there can be no mistakes at all

 

[theoldun]

Woody, we take our hat of to you for some of the most brilliant, informative and helpful posts that you have written in the Building Regulations and Planning Permission, how ever in our opinion you fall down badly when it comes to the practical side.
It is no more difficult to fix brackets under eaves felt support tray and roof covering than before roof covering. If anything we find it easier to align brackets under roof covering than after roof covering.
By fixing gutters after roof covering, you eliminate the risk of damage caused by nut carrier standing on gutter and roof tiler leaning on gutter when fixing first few courses of eaves..
Look around at any site with roof timbers standing and facias fixed. You will not see gutters fixed.
You state that gutters to be fixed before covering, and in next breath you state

I see more mistakes with post-fitted gutters. I'd only accept gutters fitted afterwards if I was confident of the builder/roofer's ability to do it right

Next time we run a house of gutters we will ask you to come down and decide whether after 61 years in this industry, you feel we have the ability to fix gutters after roof covering.
If you wanted to have a whittle woody, then you should have picked up the mistake that we made with regard to insulation, which we are now going to put right.
Kirstent. We sincerely apologise, but in our last post, due to rushing we made an error.
We wrote for insulating the slope on the raised tie, use either 300nn fibreglass or 100mm GA4000 Celotex
Do not use fibreglass at this point. With raised tie trusses top chord is normally 47x147. Leave 50mm gap between roof covering and fit 100mm GA4000 celotec between top chord and wall plate and raised tie, how ever this will only give a U value of 0.21. You can either put up with this or you can reduce to 0.18 which BRs ask for by fixing 37,5mm of PL4000 insulated plasterboard up the slope of rafters.
Just seen your last post woody in reply to the post made by nose. In our opinion nose has forgot more of the practical side of this industry than what you will ever learn.. Instead of being man enough to put your hand up and say you are wrong you just continually wriggle
Regards oldun