Cutting steel roof panels

[gunderhill]

Im putting a  roof  on my  garage using bluescope  steel panels however the morons i ordered from have made it 9cm too  long currently arguing with them  to change it  all or  cut  it, if  it all fails can and angle grinder with METAL  cutting discs be used (not the saw type  blades), I  know tin snips are  used but this is 16  panels 900mm wide with the corrugations in maybe ok for an expert but this stuff has a  guarantee and it may be voided by Bluescope.

I saw some folk say you shouldnt use some types of  discs I diamond etc

There is an issue of rust and paint damage. Hopefully  the morons  will fix  this problem but  just in case.

This is the type of metal disc i mean or is  this a  no no ?

The stupidity here sometimes really gets to you, on their bill they even drew out the correct sizes and shape 4.96  m + another 20cm for the curve,  stuck it on the roof  today and the over hang is way too  much, pruning 9cm off one end ie the other end which is straight not curved would suffice, their delivery driver also hid  this damaged section in the sneaky git. You can see the dents where he rested it  on the metal bar on his  pick up. All else  fails will contact Bluescope  head  office as this stuff isnt like the cheaper Thai stuff

 

[taninthai]

To be honest it looks fine with that over hang,the bigger the overhang the better keeps sun of walls and is not dropping water to close to your wall line.

[lopburi3]

16 minutes ago, taninthai said:

To be honest it looks fine with that over hang,the bigger the overhang the better keeps sun of walls and is not dropping water to close to your wall line.

Except there is no support so first cat fight and big bend likely.  But that said it would not be hard to weld in a support rod.

[gunderhill]

36 minutes ago, taninthai said:

To be honest it looks fine with that over hang,the bigger the overhang the better keeps sun of walls and is not dropping water to close to your wall line.

No it  falls  directly into a  massive concrete  gutter  system thats 1metre  wide in the ground for rainwater run off from the rest of the land, currently it will overshoot  this (stuck one panel on the roof  this  morning and turned  hose on full to simulate downpour) the curve should  start right at the end of the roof  beams which is as it was drawn by me and  written down with her diagram on order 4.96 metres  +20cm curved overhang to  fall directly into my concrete  gulley. heres  the  gulley it  will fall straight into the centre of  that and as mentioned the overhang is way too long now, strong winds and maybe off it  goes.

Curve should start at the end of the roof  steel as per  my arrow, the stupid thing is they drew it  all  out correclty at 4.96 metres + the curve section max 20cm see  last photo her drawing

[taninthai]

Fair enough if you have gully on floor you want the water to hit that,,it’s a easy enough job to cut 9 cm of the straight end,if the shop values customers it should be no problem for them.

just out of interest how much you pay for them sheets,,doing some roofs myself just bought the cheap tin sheets got 21 lengths 4m by 900mm cost us 252 bht per sheet.

[gunderhill]

12 minutes ago, taninthai said:

Fair enough if you have gully on floor you want the water to hit that,,it’s a easy enough job to cut 9 cm of the straight end,if the shop values customers it should be no problem for them.

just out of interest how much you pay for them sheets,,doing some roofs myself just bought the cheap tin sheets got 21 lengths 4m by 900mm cost us 252 bht per sheet.

price is  there  on  their  bill  photo  think  it  was 16  sheets  total 14588 baht = 933 baht a sheet, its painted and .35mm  thick I guess thats the thickness anyway.

Its  Bluescope steel, there is also some foam insulation stuck on,  more for noise insulation for me than insulation as ill insulate the garage roof  space with fibreglass anyway. Forgot it  includes  putting the curve in also

[vogie]

I tried cutting mine with a grinder, found the grinder would jam, tin snips were much easier.

[gunderhill]

Just now, vogie said:

I tried cutting mine with a grinder, found the grinder would jam, tin snips were much easier.

What type of  cutting wheel did you use?

[vogie]

2 minutes ago, gunderhill said:

What type of  cutting wheel did you use?

Just a normal mini grinder with the 4" run of the mill steel disc, not too dissimilar from the one in the picture further up.

[gunderhill]

1 minute ago, vogie said:

Just a normal mini grinder with the 4" run of the mill steel disc, not too dissimilar from the one in the picture further up.

Ah  Ok I saw some people using a toothed blade for  cutting steel, zipped right thru it.

[lopburi3]

6 minutes ago, gunderhill said:

Bluescope steel, there is also some foam insulation stuck on,  more for noise insulation for me than insulation as ill insulate the garage roof  space with fibreglass anyway.

It helps greatly for rain noise and also keep temperature much lower in area below - changed from Polycarbonate to insulated sheets several years ago for open carport and the temperature is very noticeably lower in area below (and nothing but open roof about 4 meters high).  

[taninthai]

Yes ours is 0.23mm thick with no insulation ,ours is definately the cheap stuff????????????

grinder should cut it just have to be gentle and take it slow.

[gunderhill]

3 minutes ago, lopburi3 said:

It helps greatly for rain noise and also keep temperature much lower in area below - changed from Polycarbonate to insulated sheets several years ago for open carport and the temperature is very noticeably lower in area below (and nothing but open roof about 4 meters high).  

My main issue  was  noise, i wasnt worried about the insulating value much as ill stick 4  inch fibreglass behind the ceiling when I do it, just waiting to see what the co.says, already tried  telling us the 9cm over was normal and  said they told us this, honestly  cant make it  up, in which case every time you buy this stuff you must allow "conveniently the 9cm"  over for your roof.

Looks  pretty clear to me by her drawing 4.96 + a 20cm curve, either way the curve should start at 4.96

[gunderhill]

6 minutes ago, taninthai said:

Yes ours is 0.23mm thick with no insulation ,ours is definately the cheap stuff????????????

grinder should cut it just have to be gentle and take it slow.

Mines aluzinc steel with the epoxy or whatever paint on, I want  durability and even for me thats a bit too thin, i saw some .5mm thick but not  coloured.

[sometimewoodworker]

2 hours ago, gunderhill said:

Im putting a  roof  on my  garage using bluescope  steel panels however the morons i ordered from have made it 9cm too  long currently arguing with them  to change it  all or  cut  it, if  it all fails can and angle grinder with METAL  cutting discs be used (not the saw type  blades), I  know tin snips are  used but this is 16  panels 900mm wide with the corrugations in maybe ok for an expert but this stuff has a  guarantee and it may be voided by Bluescope.

I saw some folk say you shouldnt use some types of  discs I diamond etc

There is an issue of rust and paint damage. Hopefully  the morons  will fix  this problem but  just in case.

This is the type of metal disc i mean or is  this a  no no ?

The stupidity here sometimes really gets to you, on their bill they even drew out the correct sizes and shape 4.96  m + another 20cm for the curve,  stuck it on the roof  today and the over hang is way too  much, pruning 9cm off one end ie the other end which is straight not curved would suffice, their delivery driver also hid  this damaged section in the sneaky git. You can see the dents where he rested it  on the metal bar on his  pick up. All else  fails will contact Bluescope  head  office as this stuff isnt like the cheaper Thai stuff

If you use any grinding disc you have voided the guarantee. The hot sparks from the grinding process will impact the painted surface and provide rust nuclei. Bluescope state that using any grinder voids the guarantee.

 

The installers for our roof used snips with extended handles to cut our roof sheets to length. It is an easy modification for any competent welder.

[gunderhill]

7 minutes ago, sometimewoodworker said:

If you use any grinding disc you have voided the guarantee.

Yes I already mentioned that it would void the warranty but if  you  look here on Bluescopes site it says this , its  not clear what exactly a metal  cutting disc is or if they mean dont use a normal diamond disc for stone etc. was thinking of the thin metal discs but heat would be an issue

• Use metal cutting discs or shears to cut sheets rather than angle grinder discs.
• http://www.bluescopesteel.com.au/go/howto/guidelines-for-using-zincalume-steel

[sometimewoodworker]

38 minutes ago, gunderhill said:

Yes I already mentioned that it would void the warranty but if  you  look here on Bluescopes site it says this , its  not clear what exactly a metal  cutting disc is or if they mean dont use a normal diamond disc for stone etc. was thinking of the thin metal discs but heat would be an issue

• Use metal cutting discs or shears to cut sheets rather than angle grinder discs.
• http://www.bluescopesteel.com.au/go/howto/guidelines-for-using-zincalume-steel

Most probably a disk with carbide teeth, the same is used in a slow speed cutoff saw and slow speed metal cutting circular saw.

 

So none of the usual cutting disks and probably a standard angle grinder is too high speed.

 

However a sheet metal nibbler would also be perfectly suitable for the job

 

You may also be able to use a jigsaw with a metal cutting blade or a Oscillating multi-tool with the correct blade

[gunderhill]

35 minutes ago, sometimewoodworker said:

Most probably a disk with carbide teeth, the same is used in a slow speed cutoff saw and slow speed metal cutting circular saw.

 

So none of the usual cutting disks and probably a standard angle grinder is too high speed.

 

However a sheet metal nibbler would also be perfectly suitable for the job

Yes thats the disc I thought of, but im hoping theyre going to sort this out, let's see. Failing them doing anything ill buy one of those  cutters  after watching a video on them they seem pretty  good, Thanks!

[grollies]

No way would I cut that. Insist they take it back or cut it themselves. You should always, always check stuff before it's unloaded.....I know, sorry.....

 

Also make you complaint re the damaged sheet. Bastards.

[Kwasaki]

8 hours ago, gunderhill said:

stuck it on the roof  today and the over hang is way too  much, pruning 9cm off one end ie the other end which is straight not curved would suffice,

I cannot understand that a extra 9cm overhang about 4 inches is so much of a problem anyhow.

Your could bend the roof sheets up at the ridge if they are covered by a ridge flashing.

If you want to cut it and they are a galvanized coated steel sheet it should be done by shear cut like with snip or a Fein nibbler sheet cutter.

To cut with an angle grinder it not the correct workman way to do it and it will invite corrosion eventually.

 

[gunderhill]

59 minutes ago, Kwasaki said:

I cannot understand that a extra 9cm overhang about 4 inches is so much of a problem anyhow.

Your could bend the roof sheets up at the ridge if they are covered by a ridge flashing.

If you want to cut it and they are a galvanized coated steel sheet it should be done by shear cut like with snip or a Fein nibbler sheet cutter.

To cut with an angle grinder it not the correct workman way to do it and it will invite corrosion eventually.

 

Its a  flat roof  no ridge bluescope say you can cut with a  steel cutting  blade I was checking which type  of blade "exactly" they meant and its the type Sometime woodworker " showed, already mentioned tin snips as the norm and I saw the power cutters also.

 

On another note.... the fasteners through the ridge or the  valley of each  sheet, I saw many Thais do it through the ridge ie the high point of the sheets BUT I saw the correct way due to expansion and possibly bolts  loosening over time was to do it in the valleys only and i know thats where the most water will run

Any thoughts on that anyone?

Remember this isnt corrugated iron type sheeting.

[gunderhill]

3 hours ago, grollies said:

No way would I cut that. Insist they take it back or cut it themselves. You should always, always check stuff before it's unloaded.....I know, sorry.....

 

Also make you complaint re the damaged sheet. Bastards.

easier said than done on 5 metre long sheets when its  windy.

[Yellowtail]

_{If I paid a premium for cut-to-length material, I would expect it to be delivered the correct length. Even if I decided to trim it myself, I would send BlueScope a nasty-gram.}

 

_{It's been my experience the screws go in the ridge.}

 

_{Fiber cut-off disk will work, but it will burn the paint and galvanized off, and it will leave a nasty burr.}

[sometimewoodworker]

1 hour ago, gunderhill said:

On another note.... the fasteners through the ridge or the  valley of each  sheet, I saw many Thais do it through the ridge ie the high point of the sheets BUT I saw the correct way due to expansion and possibly bolts  loosening over time was to do it in the valleys only and i know thats where the most water will run

Any thoughts on that anyone?

Remember this isnt corrugated iron type sheeting.

If you don't have the KLIP-LOK  system then it is usually through the ridge, the fasteners you have are not designed for valley fixing, you can get everything you need here Manual for installation

 

[Kwasaki]

2 hours ago, gunderhill said:

Its a  flat roof  no ridge bluescope say you can cut with a  steel cutting  blade I was checking which type  of blade "exactly" they meant

You have lost me until I could see drawings of the type of construction & roof design or better pictures of the whole structure I cannot see how I can help you.

To have a larger overhang at roof eaves at only 90cm would give no problem with aesthetically designed soffit finish detail.

[Kwasaki]

48 minutes ago, sometimewoodworker said:

If you don't have the KLIP-LOK  system then it is usually through the ridge, the fasteners you have are not designed for valley fixing, you can get everything you need here Manual for installation

 

Remember this isnt corrugated iron type sheeting.

[gunderhill]

4 hours ago, Kwasaki said:

Remember this isnt corrugated iron type sheeting.

 I think your confusing the 2  issues  (fasteners and cutting)I meant the curved  stuff  which is fastened thru the raised bit usually I didnt mean for  cutting, I  know those cutters  will go thru the type you show with ease and round very very tight  corners. When I talk corrugated I mean this old type stuff like this which i see is always fastened thru the highpoints  only 

[gunderhill]

4 hours ago, Kwasaki said:

You have lost me until I could see drawings of the type of construction & roof design or better pictures of the whole structure I cannot see how I can help you.

To have a larger overhang at roof eaves at only 90cm would give no problem with aesthetically designed soffit finish detail.

 the roof  is a  single  plane roof 5 metres wide on the  fall  , no  valleys/hips there is  no ridge, I don't  want an overhang that large as (already mentioned) rainwater will run off straight into a 1  metre wide drainage  channel, the extra length now means rainwater in a downpour  will run onto an area I dont want it to.

Heres  a  panel I dropped on yesterday  to see how it  looked, now fasteners thru the  valleys or thru the ridges of the sheets?

[gunderhill]

6 hours ago, sometimewoodworker said:

If you don't have the KLIP-LOK  system then it is usually through the ridge

Here its done by the Thais  usually thru the ridge but I really think this is wrong, Ive seen a  lot of roofs done with it thru the  flats, I know it  seems odd but the training schools teach this, The reason was expansion and movement of the roof slowly  loosens the bolts, the other reason is you can bolt down  so that the metal  pulls  up hard onto the fixing  battens not onto the ridge and sometimes  squashing it down if  over tight.

Had a  look through numerous sites and videos and virtually all are done thru the flats, I know it  goes against the grain and  I would have gone thru the ridges, this is  just one of many videos and still photos I  see that all go thru the flats for this type/profile (not corrugated  what I call corrugated iron in the UK) I don't know whether this is a new thing or  not, I can see advantages and disadvantages, ridges less chance of leaks of the seals fail, valleys   can  pull the metal down harder onto the rafters but more leakage if a seal fails. Ill see what Bluescope say.

 

[wayned]

The extra overhag on the side can be corrected by overlapping the panels more.  The over hag on the front can be corrected in one of two ways,:

1. cutting the panels to the correct lenght usinf an angle grinder with a steel cutting blade

2. extending the existin by welding extensionds onto the existing rafters. 

 

I would choose option two as there is never too much overhang.