Seamed metal roofing or catnic SSR2 advice required

[ruggers]

Does anyone have any information on the use of catnics standing seam metal roofs or any other companies I could speak to?

 

I'm planning to build 2 storey self build house from brick construction and the architect suggested a metal roof for the flat/low pitched porch roof, the porch is external to the house but a closed front with locked door keeping shoes and coats etc. There will be 2 external cavity walls exposed as it is built into an internal corner of the house, so other than a parapet type roof or a low pitched lean to roof and standard gutter I can't think of many options. The size is 3m x 2m.

 

Parapet roofs look a lot more prone to leaking if something fails and some of the aluminium copings for the top can be very expensive if a GRP roof is used or EPDM.

[SimonD]

Catnics is basically a Tata Steel clipped standing seam roof (Tata steel product for selfbuilders is called Colourcoat Urban). If you're looking at coated steel roof, @Kevin J will I'm sure be along shortly re the product Metal Solutions supply which is also pre formed with clip together seams but made from SSAB Greencoat PLX. The minimum pitch for these roofs is usually 5 degree although with some standing seam products you can get away with 3 degrees.

 

 

[ruggers]

Thanks. I'm able to achieve the minimum pitch easily, I'm just looking at what products are available in metal standing seam, the various prices, longevity and if possible to fit myself. If I use GRP as a lean too I'm not sure it will look as good from the front elevation of a house as a lean to roof so it would be better in a parapet style but then I've the expensive of capping off the top and it's not too straight forward the face walls are being cladded in stone and different thicknesses. Flat roofs cause more issues if they leak and creating through wall drains.

 

The standing seam metal estimate from Catnic SSR2 wasn't too bad but I don't know anyone who's used it,  It did require £300 worth of tools to self fit that i'd not use again.

Is the tata steel colour coat urban a different price or product? 

[tonyshouse]

I used quite a lot of metal corrugated tiles that. Old go down to 7.5 degree pitch looked like concrete pan tiles 

[Kevin J]

thanks SimonD everything's on the website

[ruggers]

14 hours ago, tonyshouse said:

I used quite a lot of metal corrugated tiles that. Old go down to 7.5 degree pitch looked like concrete pan tiles 

Thanks, but I need to use a plain surface because i will have slates on the main roof but can't achieve the same pitch on the porch so unable to use slates. Any other types would just look too much.
 

13 hours ago, Kevin J said:

thanks SimonD everything's on the website

Can I buy direct from the website or will I need to go through a supplier? Is there a difference in product material or price between colourcoat urban and the SSAB greencoat PLX?

[Kevin J]

Hi, you can purchase directly through the website.

should you decide the installation is too demanding, skill level for example, a training course is available. If you need tooling this is also available.

If other constraints such as time present an obstacle we provide details of competent Installers 

 

[ruggers]

I have provided plans to your colleague and had a glance over the installation guide, but theres a lot of tools required for a one off small porch roof. I thought the snaplock minght of reduced the need for as many tools , the basic tool kit required says £550? The roof is an abutment at the top and down one side with a verge on the other side. 3m wide and a 2100mm fall at 7 degree pitch, i can go anywhere between 5 and 10 but would prefer to keep it low.

 

So I could really do with an estimate of the costs including tools vs labour to compare against the estimate from Catnic/colourcoat urban. 

 

Is the greencoat PLX a different material used compared to the SSR2 of catnic?

[JamesP]

You will need 3 tools to fit the Tata / Catnic, listed below. I also purchased a metal blade for a circular saw.

 

Its straight forward to fit, nailing strip on one side and hit with a hammer and block of wood the other. 

I had 300 sqm to fit and 7 Velux to fit round which was  a bit of a challenge. 

 

You might find the delivery charge is more than the product.

 

1. 1  EAVES CLOSER CU094300

   Tools

2. 2  STUBAI PLIERS CU094200

   Tools

3. 3  FLANGE MATE CU094400

   Tools

 

[GraemeHM]

@JamesP we’ve gone round and round on metal roofing. But back looking at Colorcoat. We actually have a very simple mono pitched roof. Slight complication on the abutment and we are right down there at 5 degrees ?.

 

That said we also have two “flat roof” skylights. How much of a challenge was fitting skylights in? And where should I look to lear what’s required?

 

Cheers

[JamesP]

1 hour ago, GraemeHM said:

@JamesP we’ve gone round and round on metal roofing. But back looking at Colorcoat. We actually have a very simple mono pitched roof. Slight complication on the abutment and we are right down there at 5 degrees ?.

 

That said we also have two “flat roof” skylights. How much of a challenge was fitting skylights in? And where should I look to lear what’s required?

 

Cheers

I did spend half a day up at Tata for some basic training, no great detail. Without openings its very straightforward. You create an upstand on the Colorcoat panels to fit under the Velux flashing kit. 

Enclosed is the Tata Spec Guide, drawing ASU05 for Top Abutment as well as roof lights and drawings for a warm roof.

It might be worth getting quotes from professionals as it is a small roof, I had 300 sq metres so the savings were considerable.

 

Specification-Guide-Tata-Steel.pdf

Edited February 25, 2021 by JamesP

[GraemeHM]

@JamesPThats absolutely amazing thank you.

[ruggers]

Thanks for the photos, looks quite a big job. How do you trim them long ways for the cut ends like each end of yours being 4m ish from the photo?

I will have 1 top abutment, 1 side abutment and one verge but it's quite close to an exact sheet size, i haven't yet built it so if required for a better roof, I could tweak sizes 25-50mm.

 

How have you found the noise when it rains?

[Russell griffiths]

6 hours ago, ruggers said:

Thanks for the photos, looks quite a big job. How do you trim them long ways for the cut ends like each end of yours being 4m ish from the photo?

I will have 1 top abutment, 1 side abutment and one verge but it's quite close to an exact sheet size, i haven't yet built it so if required for a better roof, I could tweak sizes 25-50mm.

 

How have you found the noise when it rains?

You set the roof out so you end up with an even cut at both ends, then you cut the first sheet longways and re bend the upstand, do the rest of the roof and if you lucky when you get to the far end you have the same size cut, cut this and again re fold the edge. 

[Pete]

15 hours ago, Russell griffiths said:

You set the roof out so you end up with an even cut at both ends, then you cut the first sheet longways and re bend the upstand, do the rest of the roof and if you lucky when you get to the far end you have the same size cut, cut this and again re fold the edge. 

I got my roof from Catnic (same as Tata) and the first/starter panel arrives cut to size and you only cut the last panel.

[Dunny1234]

Hi all, im about to start building soon. Either zinc or catnip ssr2. The issue i have is a warm or cold roof. The zinc installer wants an extra £19k to install the warm roof, before he even starts the zinc. What’s best, and how easy is it to build up a warm roof? Thanks in advance for any advice 

[GraemeHM]

@Dunny1234We are just about to start building as well and I've been doing research on cold/vented vs warm/unvented. Our zinc installer has always favoured cold/vented. I spoke to a very knowledgeable technical guy at VM Zinc and he said "both will work if done right, but the cold/vented is more forgiving". As you probably know the issue is condensation on the underside of the roof.

[Russell griffiths]

The different types of buildup will have a major effect on other aspects of the build, having 150mm plus of insulation on top of your rafters will make finished heights higher. 

So needs thinking about quickly. 

[Kevin J]

@Dunny1234 A cold ventilated construction has been the method of construction for zinc roofing across Europe. Use 'penny gap' 25mm thick softwood boards as the deck supporting the zinc and you can't go far wrong. If there is condensation with in the roof build up the timber will be able to dry, the air will also protect the back (underside) of the zinc and allow a natural patination on the metal surface.

If you build using plywood you MUST isolate the zinc from the plywood using a structured underlay as ISO-Mat Metal. It has always been forbidden to lay zinc directly onto Plywood.

Warm roofs have become popular and IF installed correctly can offer some advantages. The Vapour Control Layer (VCL) must be specified in accordance with the level of humidity expected within the building and installed correctly to prevent moisture breaching into the roof construction - for the life of the building. 

DM Drawings if you need project specific advice or guidance?

[Dunny1234]

Thanks for the advice. My zinc guy says 75% of zinc he does is cold, and the rest warm. I can see the benefits in warm, I like the idea of voids in ceiling (lights /cable etc), and the improved thermal bridging. He saying that because it needs to be done right, and the importance of the vapour barrier, he’d want to do it. This brings the quandary, can I justify the extra £19k to just build the warm roof, before the £35k for the zinc? 
 

my architect says we can go either warm or cold, and he can sort drawings. My original quote from zinc guy was a cold roof, but my architect preferred a warm roof, now I just don’t know. Really want to buy in all the insulation soon too, as it looks like the price are going up. ?

 

thanks again 

[Dunny1234]

2 hours ago, GraemeHM said:

@Dunny1234We are just about to start building as well and I've been doing research on cold/vented vs warm/unvented. Our zinc installer has always favoured cold/vented. I spoke to a very knowledgeable technical guy at VM Zinc and he said "both will work if done right, but the cold/vented is more forgiving". As you probably know the issue is condensation on the underside of the roof.

Thanks Graeme, are you going cold roof then? 

[GraemeHM]

@Dunny1234Yes the condensation is a big concern and as @Russell griffiths says all that insulation on top of our rafters makes our roof angle more problematic. Our architect also preferred warm, but soon changed his mind ? I've read things about there being more noise on a cold roof, but not sure about that. I've also read that a vented roof keeps heat (we are south facing) away from the roof structure. Other considerations (as I understand) if you have rooflights, care must be taken to keep the ventilation open and if you are joining another building like us, then the abutment is slightly more complicated.

[GraemeHM]

@Dunny1234I should say that are also considering using an aluminium roof PREFA / Preflaz and it seems to have a good reputation.

 

[Dunny1234]

2 minutes ago, GraemeHM said:

@Dunny1234I should say that are also considering using an aluminium roof PREFA / Preflaz and it seems to have a good reputation.

 

Definitely looking at alternatives, the catnic ssr2 looks good. 
 

my architect has suggested that if we go with a cold roof, 150mm pir between rafters, and 38mm pir back plasterboard over rafter to sort the cold bridging issue out. But, I cant how I’m going to install down lights, and cable this way. Alternative, with warm roof is 165mm on top.

 

We’ve got large rooflights, and a couple of sun tunnels too, will this be difficult with a warm roof? There definitely seems to be a greyish area of using warm roofs and a standing seam type roof. It’s driving me nuts 

 

[Bramco]

17 minutes ago, Dunny1234 said:

He saying that because it needs to be done right, and the importance of the vapour barrier

 

1 hour ago, Kevin J said:

Warm roofs have become popular and IF installed correctly can offer some advantages. The Vapour Control Layer (VCL) must be specified in accordance with the level of humidity expected within the building and installed correctly to prevent moisture breaching into the roof construction - for the life of the building. 

 

So doing it right is speccing the right VCL in accordance with the level of humidity and leaving a ventilated gap? Or is there more to it?

 

Is this an issue only with standing seam?

 

We were looking at Prefa standing seam but have gone back to what was on our planning application which is corrugated steel for both the roof and the cladding.  Mainly because of the cost of wrapping the whole thing in 18mm ply or OSB to support the standing seam.

 

Our timber frame co will install the VCL and 25x50 counter battening. The plan is to then mount purlins and the corrugated on that - the corrugated would have the inside coated with an anti condensation coating and of course the whole gap behind the roofing and cladding would be vented (and insect and vermin proofed).

 

Has anyone done this? Any advice?

 

Simon