Advice on materials/products for roofing work

[Holly64]

Hello

I need my roofs above my ground level bay windows to be replaced (see photos). I have got quotes and the materials costs seem quite high (but maybe not?). One of the pitches of the roof needs raising - the other-one doesn't. One of the quotes is quite detailed, naming products and and weights of breathable underlay, the other isn't so detailed.

The quotes state 'supply and fit 9mm White PVCu Hollow Soffit (TnG)' for side cheeks.

I have looked up what I think is the product at Toolstation and it says not recommended for cladding exterior of house. My house is on the top of a hill and its quite scary at times as the wind just howls around the building. If a window is slightly ajar, the force of the wind flings it wide open.

Should a different product be used?

Both roofers were supposedly quoting me for using clay tiles, but there quotes show concrete tiles which I assume are cheaper?

Does the roofer have to work with a carpenter? Or are there roofers who do the carpentry as well and then they just use either another roofer or a labourer?

Many thanks for advice/opinions please.

 

[datarebal]

i see two rooves. One which I guess you are cladding the end. id use proper ship lap or similar. hollow might be a bit weak
concrete tiles are cheaper , you currently have concrete plain tiles over the left bay .
The longer roof from the door to the right hand side of the house is too flat roof pitch for plain tiles
it is leaking now but possibly onto the underlay.

 

[Holly64]

Yes, two roofs.

The longer roof, the pitch has to be raised.

I had to look up shiplap and I see it is wood. That is what's there at the moment. I wanted to try and make it maintenance free. Is there another product that can be used instead of the Hollow PVCu or the Shiplap?

Both the roofs leak!

 

[datarebal]

yes plastic shiplap, or maybe fortex or https://www.cedral.world/en-gb/clad...hl0Stq61Y-5cTYvhWqXfQYr7X4hPnv1RoCkugQAvD_BwE
its not just timber..

 

[Holly64]

Next Question's (sorry for asking so many!)

One roofer has quoted supply and fit cement fibre under-cloak to the verges under the batten ends - is this basically a cement finish?

Is there another type of finish or product? I guess this is just for aesthetics?

Should the roofs be vented or insulated? Currently we have a small sofa in the bay window and it does get noticeably cold in the winter.

 

[datarebal]

The undercloak is for a mortar bedded verge. Much like you have now
there are other products for dry verges , no mortar. They tend to be plastic and fade
insulate and vent

 

[^woody^]

The quotes state 'supply and fit 9mm White PVCu Hollow Soffit (TnG)' for side cheeks.

Well you can stop them right there.

Soffits are horizontal, and hollow board should not be used vertically due to the exposed nailing. So a hollow soffit board is for horizontal soffits that don't get wet.

But cowboys tend to use them because its cheaper than proper shiplap, and its quicker to do. And only idiots actually specify it on a quote.

Has either of them mentioned building regulations and the requirement to insulate?

 

[Holly64]

Well you can stop them right there.

Soffits are horizontal, and hollow board should not be used vertically due to the exposed nailing. So a hollow soffit board is for horizontal soffits that don't get wet.

But cowboys tend to use them because its cheaper than proper shiplap, and its quicker to do. And only idiots actually specify it on a quote.

Has either of them mentioned building regulations and the requirement to insulate?

One has, one hasn't.

I asked the roofer who did mention it, if it was the celotex (or whatever its called) insulation and he said no, its the insulation that comes in rolls. Is that correct?

I really do need to get on with getting this done as I need new windows and I can't get the windows done until the roofs are proper water tight. I have actually had a third quote but I could tell straight away the guy was just out to rip me off - he said it would take 3 men 7 days to do the roofs!

 

[^woody^]

The insulation can be whatever you like as long as it meets the required "u-value" - ie insulation value. The thickness and type will then determine how it is fixed and where - ceiling or rafter level.

I've specified lots of roofs over the years and invariably the roofers - proper firms, and good tradesmen know how to tile and felt, but not how to form roofs, design roofs, ventilate roofs, insulate roofs. The timber work (structure) and any cladding always seems to be just outside of their competence too, even though they must surely have come across it many times in the past.

And that's the problem for the home owner. The roofers tell you what they think will do, and even if you check on here, much of that type of work will be made up as they go on site, and unless its specified for them and inspected, then you just wont know how correct it is

Another thing to assess them by would be ask how they are going to fit the flashing. Flashing should be chased into the wall and not into the render. Many try and get away with the latter.

 

[Holly64]

The roofer who mentioned the insulation, his quote says the flashing will be chased into the wall by 25 mm. His business is big ish - 9 permanent roofers, but he specified the hollow PVCu for the side cheeks.

The second quote is from a contractor. I am hoping I can get the contractor to change some of the products and get him to confirm in writing a more detailed specification. He also wants to charge me £200 to take away the old tiles, I will ask him to leave that and I can do a few tip runs instead!

 

[catlad]

......

 

[datarebal]

We have come across plenty of designers that spec materials and systems that are wrong for purpose or long winded or even just poor practice.

Just tell your preferred guy the mats you want him to use. hollow soffit where it belongs and ship lap where it should be wood or upvc

watch the new roof pitch and lead slate to the svp

 

[datarebal]

The answer is in your question .
What does the shingle company say..