Seamed Roof - what to have Zinc/Aluminum/Greencoat

[Caroline]

Hi all

 

I am going to have a seamed roof, thinking of Alum/Greencoat or Zinc, not much difference in price, zinc (around 5% more expensive than the other two).  

 

Any advice would be appreciated.

 

Thank you

[JohnMo]

I had the same dilemma, in the end went Sika Sarna S327 standing seam. A seam welded and mechanical fixed EPDM.

 

[Caroline]

Looks great.  We are in the South East, did you go for this material due to being in Scotland, harsher weather.  Would be interested to know why you chose this material please?

 

 

[Russell griffiths]

I used green coat plx, very happy with it. 
when I priced it it was half the price of zinc. 

[JohnMo]

  On 25/02/2025 at 16:35, Caroline said:

Looks great.  We are in the South East, did you go for this material due to being in Scotland, harsher weather.  Would be interested to know why you chose this material please?

 

 

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Cost and ease of getting an installer.

 

Cost was £14k for system chosen, that included all the correct underlay, all edge trims etc.

 

Alternatives priced 

TATA standing seam, 2x quotes £18k (lots of detail not included) and £29k

Zinc was about £30k, quote had no details of what was or wasn't included.

[Caroline]

Wow, a bargain.  We have approx 320sqm and have been quoted £54k for Alum/Greencoat and £2.5k more for Zinc, this does include guttering and downpipe in same material.  There are no veluxes in the roof the only opening is for log burner flue and the roof is similar to yours oblong 28m x 10m with an apex on one side.  Does your installer work nationwide in the UK?

 

[Caroline]

  On 25/02/2025 at 16:15, JohnMo said:

I had the same dilemma, in the end went Sika Sarna S327 standing seam. A seam welded and mechanical fixed EPDM.

 

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  On 25/02/2025 at 17:15, Russell griffiths said:

I used green coat plx, very happy with it. 
when I priced it it was half the price of zinc. 

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I have heard good things about Greencoat but it is the same price as alumin and not much less than zinc.

[JohnMo]

  On 25/02/2025 at 18:12, Caroline said:

Wow, a bargain.

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Forgot to mention 220m² approx.

[JohnMo]

  On 25/02/2025 at 18:12, Caroline said:

Does your installer work nationwide in the UK?

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Just NE Scotland I believe. But there is a network of install companies nationwide. Sika only sell to approved installers I was told.

[Mr Blobby]

  On 25/02/2025 at 16:06, Caroline said:

Hi all

 

I am going to have a seamed roof, thinking of Alum/Greencoat or Zinc, not much difference in price, zinc (around 5% more expensive than the other two).  

 

Any advice would be appreciated.

 

Thank you

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We have prefa aluminium, which is ok, but the ridge detail could have been better, something I didn't think about at the time.  Confirm the details like this before install.

Roof buildup is also important.  There are standard guidelines for metal roofing with vented timber under the standing seam. We used sarking board instead of ply, and I think it's better for not much extra cost.

[Russell griffiths]

  On 25/02/2025 at 18:14, Caroline said:

 

I have heard good things about Greencoat but it is the same price as alumin and not much less than zinc.

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Who have you had quotes from, I used metal Soloutions in Bolton. 

[Tosh]

We used Greencoat, that was based on the cost of Zinc at the time and the installer saying we'd never know the difference once it was installed. He said one of the main issues with zinc is due to its softness hence you tend to get more oil canning with it especially over large uniform areas. So he tended to use it more on complicated jobs with lots of detailing e.g. bandstand roofs. Bear in mind that some of the replies are based on Greecoat pre formed and diy/contractor installed whilst others, like me, are based upon specialist subbies with the coils arriving and formed on site with specialist kit. The difference in £/m2 will account for this so make sure you understand what you're asking for and getting. I don't think you'll have a choice with zinc, as far as I'm aware it will have to be formed on site unless a supplier has started pre forming it but not aware of any.

[Big Jimbo]

@Tosh That looks very bloody nice.

[Tosh]

  On 25/02/2025 at 20:05, Big Jimbo said:

That looks very bloody nice

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Very kind words @Big Jimbo, like many on here been a labour of love. Living off site, only working on it at weekends, kids, dogs blah blah.

[Andehh]

  On 25/02/2025 at 16:15, JohnMo said:

I had the same dilemma, in the end went Sika Sarna S327 standing seam. A seam welded and mechanical fixed EPDM.

 

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We did the same! Very happy with it, albeit it we had issues with a bad batch of insulation sheets underneath shrinking and lifting, so it nows looks like a patch were quilt where they had to do localised repairs.

[Caroline]

  On 25/02/2025 at 19:50, Russell griffiths said:

Who have you had quotes from, I used metal Soloutions in Bolton. 

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We are in the South East.  We want to go to someone who will supply and fit.

[Mr Blobby]

  On 25/02/2025 at 20:54, Caroline said:

We are in the South East.  We want to go to someone who will supply and fit.

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One more thing to consider is the width between seams.  Standard is 600, but we chose to have 400 centres.  Looks better and possibly less canning with 400 centres because we have only one panel with signs of canning. More expensive of course, but not a massive difference.

[Russdl]

  On 25/02/2025 at 21:28, Mr Blobby said:

Standard is 600, but we chose to have 400 centres.  Looks better and possibly less canning with 400 centres

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That’s a good point. We have zinc, formed on site and 600mm centres. 400mm would have looked better.
 

Pigeon shite eventually doesn’t wash off completely either, so if you can get anti roosting wires/spikes fitted economically consider those as well.