Corrugated Metal Roofing

[Tom's Barn]

Good afternoon forum...

 

We have had the planners insist on corrugated metal roofing for our new house that is surrounded by fields. What seemed to be a great solution to start with is actually causing a slight headache.... My issue is finding a contractor that has fitted corrugated metal roofing including velux lights. Many have done agricultural work but not many have ventured into domestic house installs. Therefore, does anyone know of a good metal roofing contractor with these sorts of skills?

 

Many thanks in advance of your assistance.

Tom

[Ed Davies]

It really helps with this sort of query to include your approximate position (which county, say) in your profile.

 

(In the unlikely event anybody knows a metal roofing contractor who wouldn't be too fazed by Velux windows here in the north east of the island I'd be glad to hear.)

[Cpd]

I spent a long time looking at velux installations in corrugated tin and NOT ONE was done well....... I looked at why they were done badly and then sat down and worked out how to do it well. I did the layout and install myself as the devil is in the detail if you want it all to line up and work properly. The most important aspect for me was the position of the windows and there size in relation to the corrugations in the tin sheets. You need to make sure that one sheets edge will end with with a non cut  downward sloping corrugations that falls directly into the inner gutter of the velux..... you then need to know that the windows width is also correct so that the far side gutter lines up with the next sheet of tin enabling that tin edge to fall in the opposite velux gutter...... then if you have multiple windows (I had 4 in my roof) you need to make sure that they all correspond with the corrugations.  There really is very little to play with on the set out as the tin does not allow for error, you get about 10-20mm of space in the flashing gutter to play with but you really want the tin edge  to fall in the middle as if it’s to close to the window it could block up with leaves or moss, to far and it’s not going to be as effective, also ANY error will be carried over to the next window as the corrugation spacing is set.  It’s possible with very carful layout but if this is done wrong your going to have another example of how not to do it.......  if you find a contractor that says they can do it INSIST to be able to go and look at one of there installs..... I visited 3 different installations done by 3 different professional roofers and I would not have payed for the work...... 

[Mr Punter]

A great looking job @Cpd. I can see how careful setting out is crucial for this.

[Ferdinand]

If this is a big problem, as it seems, I would expect Velux to have a list.

 

Ferdinand

[Tom's Barn]

Hi @Cpd

 

thank you so much for your detailed information and pictures that really helps. It is also worrying that you have seen multiple installations and all of them have issues.

 

My project is just outside Cirencester if that helps with any recommendations. However, I know that many skilled roofers will travel in order to complete specific works.

 

Any other comments regarding an install or learning regarding velux and corrugated roof details please let me know. I am going to contact velux now; many thanks for the idea @Ferdinand

 

Regards

 

Tom

[Tom's Barn]

Ok Velux state that you must use the EDJ flashing kit with the roof light when combined with corrugated roofing and a slope between 15 and 90 degrees. The document is just a series of pictures which I assume will be good for anyone who has installed these before. I will keep you posted on progress but this is a very useful start. Thank you.

 

Customer Support Mailbox <customer.support@velux.co.uk>	16:19 (10 minutes ago)
to me Good Afternoon Tom,

Thank you for contacting VELUX.

Please see attached, the installation instructions for installing a VELUX window into corrugated sheeting. 

If your corrugated sheeting:
> Has built in installation (is double skin) + is being used on a roof pitch of less than 15° - You will need to create an on site upstand and use a VELUX ZWC Special Head Flashing
> Has built in installation (is double skin) + is being used on a roof pitch of more than 15° - No upstand will be required however you will still require a VELUX ZWC Special Head Flashing.
> Has not got built in installation (is single skin) + is being used on a roof pitch of less than 15° - You will need to create an on site upstand and use a VELUX ZWC Special Head Flashing
>  Has not got built in installation (is single skin) + is being used on a roof pitch of more than 15° - You will need to use our EDW flashing kit (standard installation) or our EDJ flashing kit (recessed installation).

Please follow the below links to get access to the relevant information for your requirements:

ZWC Window Profile Set - Single Installation 

EDW Installation Instructions

EDJ Installation Instructions

 

Tom

Edited March 19, 2019 by Tom's Barn

[Cpd]

Looks like your on the right track. 

Just be aware that you need to be carful when it comes to this part of the flashing, you want to get the tin as far up near the window as you can without damaging the flashing, it’s not as easy as it looks. If your in a windy location (I am in a very exposed spot) then I would advise adding in a couple of fixings as shown in my photo, it’s not a good thing to be screwing through a flashing  but for me when it was not done the flashing would lift in wind and rain tracked straight up the corrugations and under the flashing. I flattened a very small section of the flashing, drilled the holes in the centre of the flat spots and put plenty of CT1 in and around before screwing down. It’s withstood 75mph + winds over the winter without any damage. 

[Cpd]

Ooo I just saw this in your instructions about cutting the tin of at an angle, I either missed this or it’s been recently added but definitely a good idea to help with getting the tin up nice and high and getting the flashing to sit down snug.  

[Tom's Barn]

Hi @Cpd

 

thank you for the additional information. I had noted from the initial photos how you have screwed down the flashing in order to stop lift in strong winds. The cutting is also a good idea that I had not really focused on. I assumed from various bits of info online that the valleys should also be turned up using a special tool as a way of stopping wind driven rain. Do you do this on your roof?

 

Also, on the ridge how did you ensure wind driven rain was not pushed under the ridge profile. The profile you have is not one I have seen before. Can you let me know where this came from; it is definitely different from the ones I have looked at to date.

 

Many thanks for your detailed support on this matter. When the council first insisted on this I thought great, a nice simple roof covering but I am learning that it is but you need to get the detail just right.

 

Tom

[Cpd]

The velux flashings are complete with pre made valleys and DO NOT need adjusting AT ALL. The flashing apron that needed the extra fixings is designed to be moulded into the profile of your desired roof. I use this type of ridge as I have it on my two other buildings either side of this one and I wanted to keep it looking uniform, however I WOULD NOT recommend this type as it is NOT SUITABLE for this job without adapting it at the cost of lessening it’s life span. I will at some point replace with the recommended ridge. To stop water blowing up as it does where I live you need to insert a rubber strip, with the correct ridge this would work brilliantly but with this ridge it was a right faff to fix and I had to depress the edge of the ridge in every corrugation to get it to hold the rubber in place....... so go with the standered ridge. I would also highly recommend getting a slightly different sized flashing than standered for the gable ends, it’s normally 200x200mm wide but this looks really shed like from the end of the buildings instead consider getting it at 200x115mm the 200 goes on top of the tin giving good coverage and the 115 goes over the gable and looks way better than 200mm and still works 100% any other questions just ask. Col  

 

just tried to to upload photos but it’s refusing to work..... I will try again soon. 

[Cpd]

[Tom's Barn]

Hi Col

 

many thanks for the pictures; the house looks great. Your advice re the edge flashing is spot on and matches recent advice from an architect who built a school building with a corrugated roof and vertical timber.

 

I really like the three windows at the top of the gable.

 

I have just been looking at the tinhouse on the Isle of Skye. The corrugated roof Alan has fitted is very good and the detailing around the skylights looks as impressive as your work.

 

Thanks again for all the details.

 

Tom

[Tosh]

You could do a search on ftmrc.co.uk but these are specialist metalwork contractors so they come with a premium regardless of the material they're working with. You need to ask yourself if you'd get value for money from those guys especially if it's a relatively straightforward design.

It might be worth dropping into a local steel fabricators as they're often a good source of contacts for various types of cladding installation.

[Tom's Barn]

thanks @Tosh good shout. I will try our local fabricator as he has done a few bits over the years. I have just been in touch with Alan at Tinhouse on the Isle of Skye and he tells me he used Velux windows with standard flashings for a corrugated roof. All has worked well but you need to be careful with the detailing and height of window. That information alone is extremely useful. 

Tom

[Cpd]

2 hours ago, Tom's Barn said:

the house looks great.

Hahaha...... it’s my shed ! It was seriously damaged in a storm and needed reroofed and one job led to another and I I ended up re cladding about 75% the velux were the prefered option over clear sheets of corrugated as you can open them and this helps with  ventilation. I got given a huge amount if new double glazed glass for nothing and try and use it where I can, I was playing around with a lot of ideas and in the end I liked this configuration on the gables, the aim is to give a sense of familiarity to a church window but not so much that it could be mistaken for trying to be one....... if you get what I mean!.  I am rebuilding the doors at the moment, there are three as it used to be a very traditional threshing shed with two doors exactly opposite each other  so the wheat  could be beaten and the chaff would blow out the opposite  door, the third door was probably where the animals or humans lived, I am replacing all the doors with stable doors so you can open just the top section if you like, again great for lots of ventilation. The upper level comprises of two mezzanines and would  have been used for storing wheat and hay or other goods you wanted to keep dry. Ok well off topic now........ 

[Tom's Barn]

Sounds like a great project Col and great to be able to reuse stuff you have been given. I never get given anything!

 

Good luck with the remaining works and I will keep you posted on any other learnings.

 

T

[scottishjohn]

Hmmm.

maybe an opening for making grp frames to fit  velux windows to corrugated roofs 

I made something like this when  i built my workshop as i wanted  to fit a  30"extraction+ input  ducts through the roof

take a new sheet use it as a mould to make the base corrugated then you can build up  a wood frame to fasten the velux too

then use layers  of grp to cover the wood frame to bond it to the base section  and you have a purpose made cassette to fit to your roof profile .

i suggest 3 or 4 layers and coated with grp roof gel cost --then its UV proof,you can get dyes to make it colour you want

easy to fit to roof and seal 

you can offset the velux frame to corrugations as you want   to make it look right 

might seem to  be a long way for a short cut but will be perfect fit 

 

 

[Tom's Barn]

thanks @scottishjohnI knew you would have a solution. This for me, being a simple chap, is too involved. Alan at the Tinhouse said his standard velux flashings were working well and he fitted them himself. I think I will try this route to start with. Thank you for the idea though. I will keep it in my list of options should we hit issues.

 

thanks

[stuwindsurf]

On 12/03/2019 at 15:58, Cpd said:

I spent a long time looking at velux installations in corrugated tin and NOT ONE was done well....... I looked at why they were done badly and then sat down and worked out how to do it well. I did the layout and install myself as the devil is in the detail if you want it all to line up and work properly. The most important aspect for me was the position of the windows and there size in relation to the corrugations in the tin sheets. You need to make sure that one sheets edge will end with with a non cut  downward sloping corrugations that falls directly into the inner gutter of the velux..... you then need to know that the windows width is also correct so that the far side gutter lines up with the next sheet of tin enabling that tin edge to fall in the opposite velux gutter...... then if you have multiple windows (I had 4 in my roof) you need to make sure that they all correspond with the corrugations.  There really is very little to play with on the set out as the tin does not allow for error, you get about 10-20mm of space in the flashing gutter to play with but you really want the tin edge  to fall in the middle as if it’s to close to the window it could block up with leaves or moss, to far and it’s not going to be as effective, also ANY error will be carried over to the next window as the corrugation spacing is set.  It’s possible with very carful layout but if this is done wrong your going to have another example of how not to do it.......  if you find a contractor that says they can do it INSIST to be able to go and look at one of there installs..... I visited 3 different installations done by 3 different professional roofers and I would not have payed for the work...... 

 

Hi, I hope you don't mind me hijacking this thread but I am about to fit some velux windows in some box profile roof sheeting and have been struggling to find any info ref install until I came across this post.

I wonder if you can help/advise, I am building a new workshop and the roof construction is going to be 12mm OSB board over roof timbers, then a layer of breathable felt finished with box profile metal sheets 34/1000 0.7mm thick. I have 3 x older style velux windows to install GGL C02 which came with slate flashing kits. I have been in touch with velux to ask what flashing kits I need for the above mentioned roof sheet and they have advised me to either adapt their EDW kit or using the ZWC trim kit (which I already have as part of the slate flashing kit) and special head trim 606189CO, then manufacture my own flashing on site.

Although having successfuly fiitted a couple of Velux windows about 20 years ago, I am unsure how to manufacture my own flashing. Can I ask did you use an off the shelf flashing kit for the quoted install? If so could you advise which kit you used?

I can pretty much space the velux windows where I like, so I should be able place them to line up with the correct edge of the profiled sheets. Do you think I would be best to get the flat section between the profiles lined up with the edges of the velux? Hopefully I have attached a drawing of the sheet profile...

I hope you can help!

Many thanks, Stuart

[Cpd]

Hay Stuart, yes I used off the shelf flashing kits that did not need any alterations, I am not sure of the flashing kit code but it’s the one designed for wriggly / corrugated tin, I will see if I can track it down..... I’m pretty sure it’s not the slate flashing kit as I have used that on another roof and the skirt is very different. (Photo included) I am also pretty sure that like your tin my tin has a high edge on one side and a low edge on the opposite side, you want the low edges to go into the velux gutter not the high edge as this will not be as effective... I think I just turned the sheets around to get a high edge to fall into each gutter, you should lay the sheets in a specific way to so that the exposed edges are not facing the prevailing wind, but to get them to fit into the gutter on both sides of the velux you need to break this rule..... my roof FACES the prevailing wind so it did not matter as the wind NEVER blows from either side as I am in a narrow glen facing  the prevailing wind. But it may be something you need to consider. I can’t think of why the flashings I used would not work with box profile, but I would need to see the exposed flashing again to be sure that it would work 100% 

10 hours ago, stuwindsurf said:

Do you think I would be best to get the flat section between the profiles lined up with the edges of the velux?

No you need to get the edge of the tin to line up with the middle of the inner gutter, remember that the tin has two different edges, a high edge and a low edge, you want the LOW edge to fall into the gutter, depending on the spacing between the box profiles, (wriggly tin is better as it gives you more options ) you then want the the next sheet of tin to fall with its edge exactly in the centre of the gutter on the other side of the velux......... this is where it may get tricky because you are using box profile and there is NO GUARANTEE that the pre set spacing of the box profile will match the width of your windows.......  if it does not match then it’s not going to work FULL STOP. 

 

Ok have a think about what I have said and come back to me if you have more questions. 

 

I think your your going to need a bit if luck as it will be pretty unlikely that the box profile will match your existing window widths but here’s hoping...... 

photo of slate flashing kit, note the skirt is rigid and you want the flexible one as shown in my earlier photos.

[Visti]

Some fantastic tips @Cpd, above and beyond in detailing the details! 

 

We're about a month from installing our and also struggling to find competent contractors for both the corrugation and windows together. This gives me some confidence that we can get it right, even if it has to be DIY at the end of the day.

[bissoejosh]

I haven't' got anything to add in terms of detailing but would just say it is very DIY'able with careful planning. I did 130m2 on our roof and a smaller lean -to section with no real dramas. I used cladco as they were local to me, no issues and helpful on the phone. The roof has cost so much less than any other option and I approached the job knowing if I made a mistake a whole sheet (4.3m long) was only £37  approx worst case so not disastrous. I also had custom flashings made with 100mm on the cladding edge to help make them less obvious. I'd be tempted to go smaller again if I started fresh. 

 

Velux also very helpful on the phone.

 

I used @Crofter blog for inspiration in lifting / sliding the sheets onto the roof with a rope and rail system, made doing it shorthanded manageable. 

Edited May 19, 2019 by bissoejosh

[stuwindsurf]

On 12/03/2019 at 15:58, Cpd said:

 

 

 

 

 

Thanks for the replies and thank you CPD for your detailed reply it is very much appreciated.

I have measured the profile of the roof sheet and the width of the Velux windows and it should work nicely. The width of the windows is 55cm and the distance between the profiles allows for the low sections to fall either side of the windows which is perfect!

What I am thinking about doing is to utilize the slate tile flashing apron, trim it down a bit in length and with some Velux ZZZ 166 corrugated flashing make my own apron. The plan is to fix the Velux ZZZ 166 corrugated flashing to the bottom of the window frame and dress over the roof panel, then fit the trimmed down slate apron over the top with a strip of 50mm x 1.5mm Butyl double sided tape between the two to stop any water being blown up between. The slate head flashing should work fine as I can get a foam filler matched to the sheet profile which I can slip in under the edge of the roof panel just above the window to keep out and wind/rain/snow etc. Then down the sides of the window I plan to fold/fabricate some 200m wide lead flashing to 90 degrees which will then tuck under the head flashing and overlap the apron flashing. Where the roofing sheets overlap the fabricated side flashing I plan to again put some Butyl double side tape to seal up the egdes to stop wind/snow etc.

I'm pretty sure this should work, but if any one can see anything I have overlooked please feel free to comment!

I should probably also add/fold some lips to the edges of the side flashing and sides of the apron flashing to stop any water creeping out to the sides?

Edited May 20, 2019 by stuwindsurf
added info

[canalsiderenovation]

I don't know if anyone is close to Shropshire but I'd been in to a local firm called Excelclad at Prees https://www.excelclad.co.uk/ and got chatting to a local contractor who came round to chat about our plans (all before we got permission) just to check out my thoughts on materials, insulation etc and I was able to drive by a property they had done work on. I was concerned as we have 10 Velux windows on our plans...

 

The contractor details are https://www.facebook.com/www.jcooperandsons.org.uk/

 

As I said I've not used them but maybe worth checking them out specifically if you are looking at a corrugated steel roof like we are.