How to make cut out for windows, and how to install insulation/roofing?

I am just wondering on what is the best method and tools to use to make the rectangular cut-out in my CBond walls to install windows? I want to get the cuts as straight and neat as possible.

Also, I am now up to the stage of installing the roof insulation (Protherm Reflecta-Cell) and the CBond roof sheets. I would be interested in hearing on suggestions on what method people use. I am considering first marking out and drilling all the screw holes for the roof sheets while they are still stacked in a pile on the ground, then installing them onto the purlins to get the holes aligned right with the purlins, then going back and taking off the sheets one by one, installing the insulation underneath as I go along. I think to first lay down the insulation, then the roof sheets, might be a bit tricky in terms of trying to get the insulation to stay in place, and also in lining up the holes in the sheets with the purlins when you can't see them with the insulation inbetween.

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Originally Posted by FlyingDuck

I am considering first marking out and drilling all the screw holes for the roof sheets while they are still stacked in a pile on the ground

You don't want to do this, rarely works out and you end up with more holes then needed

I think to first lay down the insulation, then the roof sheets, might be a bit tricky in terms of trying to get the insulation to stay in place, and also in lining up the holes in the sheets with the purlins when you can't see them with the insulation inbetween.

Roll out the first layer of insulation and secure ends using magnets, you can get them specially for this purpose, then lay first sheet on and secure one edge to fix sheet in place so that you can then stand on it. Then you can feel for the purlin thru the foil and mark on sheet for fixing screws. Put another row of screws in the second or third corrugation dependent on what screw spacings you are using, from where the next edge of sheet overlaps.

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You don't neeed to drill screw holes. The screw will push through the sheet.

Tools

Tools, the idea of drilling the holes in the sheets while stacked on the ground is to get the holes aligned, not to make it easier to screw through. When the sheet is placed on the roof you won't be able to see the purlin underneath it, so having the holes pre-drilled saves having to guess where it is or using string lines. I saw someone do this will the wall sheets and it worked out okay.

Perfect... in theory... As long the entire structure is dead square.

When I did mine and put the insulation mesh up first, then the insulation and the sheets row by row. I never thought of magnets, but I used gaffa tape to tape the edges to the purlins while I screwed the sheets on, that way I didn't have to worry about removing magnets. I started with screws in the first rib of the first sheet (except at the top where I put the screws in the valley as the ridge cap screws go through the tops of the ribs), then feeling where the purlin was through insulation, mark the sheet in the second valley. Then with the next sheet, using the mark as a guide, put a screw in the overlap. Once I had the whole roof up, I used my spirit level (or any straight edge) to mark the sheets between the screws, and fix all the rest of the screws.


As for your windows, I'd start from the edge of one sheet. Less cutting.
But I've never liked windows in my sheds. Less secure. (Yes, I know it would only take a cordless drill, a driver bit and two minutes to get into most sheds, but out of site, out of mind.)

Thanks for the replies so far. Anymore ideas on how to put up the insulation and roof sheets?

What tool is best for making the window cutouts - tinsnips, angle grinder, or what?

I've used a small angle grinder with a very thin cutting blade to trim up some old tin for lining some parts of my shed interior ie. included a doorway - worked really nicely.

An angle-grinder's really not recommended on colourbond. :no: It overheats it and damages the protection so that you're far more likely to have corrosion problems further down the line....

I'm a tin-snip kinda guy, but any other "cold cutting" method will do... a nibbler (I wish!) or even a jig-saw at low speed with an appropriate blade.

Good point Skew,
I'm certainly no expert.
When my shed was being built, I quizzed the builder about what they used to cut colorbond for doors etc.. He said that he had tried many tools over the years & that the one that he recommended was a Malco power shear that bolts onto a cordless drill. Looked like an unwieldly contraption but he demonstrated a high level of cutting precision with this tool ie. straight & curves He also used traditional tin snips as well.

Tin-snip are fine (as I said, that's what I use) but to do a good job - and to nake it easier - you really need 3 different ones. A LH set, a RH set (Wiss is probably the most common good brand) and a straight set. (I like my 12" Footprints.)

I've never used the Malco power shears myself, but I've seen used and you're right - they work well... but there're times you still need the snips.

If Flying Duck doesn't already have all 3 types of snip and doesn't intend to do a LOT of cutting, he'll probably find it cheaper to buy a cheap jigsaw and appropriate blade. :rolleyes:

The plumber used electric tin snips to do the edge of a roof I just had installed and I am not real happy with it because the edge has a slight "wavy" effect from the snips. He used a nibbler for the transverse cut which gave a much better finish. Wish he had used it on the longitudinal cut.

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Originally Posted by Metung

The plumber used electric tin snips to do the edge of a roof I just had installed and I am not real happy with it because the edge has a slight "wavy" effect from the snips. He used a nibbler for the transverse cut which gave a much better finish. Wish he had used it on the longitudinal cut.

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Rather then cut the edge of the roof, you should have just lined the sheet up with the edge and let the sheet overlap more on the join.

You would then have a nice clean line :2tsup:

That's probably what I would have done if I had been allowed to instal it but,as we all know, I'm not. Sorry, just finished responding to a thread about rangehoods and the carry over factor is still in existence.

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Originally Posted by FlyingDuck

I am just wondering on what is the best method and tools to use to make the rectangular cut-out in my CBond walls to install windows? I want to get the cuts as straight and neat as possible.

Also, I am now up to the stage of installing the roof insulation (Protherm Reflecta-Cell) and the CBond roof sheets. I would be interested in hearing on suggestions on what method people use. I am considering first marking out and drilling all the screw holes for the roof sheets while they are still stacked in a pile on the ground, then installing them onto the purlins to get the holes aligned right with the purlins, then going back and taking off the sheets one by one, installing the insulation underneath as I go along. I think to first lay down the insulation, then the roof sheets, might be a bit tricky in terms of trying to get the insulation to stay in place, and also in lining up the holes in the sheets with the purlins when you can't see them with the insulation inbetween.

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where abouts in brisbane are you i am near brisbane on the north side it would be better to show you how to do the roof, its too hard to explaine if you haven,t done it before ,give me a pm. have put up countless colourbond roofs,and can show you also how to cut out your doors ,windows etc, bob

ps dont pre-drill the sheets for god sake you will regret it.bob