Cutting corrugated plastic sheet roofing.

Discussion in 'Carpenters' Talk' started by tore81, Mar 25, 2016.

  1. tore81

    tore81 Screwfix Select

    Hi all

    I'm after a bit of advice on how to cut the plastic sheeting as I had some difficulty cutting and marking,

    It was ok as It wasn't really seen on this particular project, but I always like to know the correct method.

    First of all marking, I used tape as you can't pencil line on, and market didn't work great.

    And next how to cut, tried multi tool did the job but no finish. Any ideas?
     
  2. Neil1987

    Neil1987 Member

    Hacksaw has produced the best finish so far for me but involves bending sheet
     
    tore81 likes this.
  3. DIYDave.

    DIYDave. Screwfix Select

    I've cut a few sheets of this myself

    Measure down both sides, mark with a felt tip or sharpie, lay a straight edge across 2 marks and then you can mark the tops of the ridges

    Alternatively stick a length of making tape across width and mark with a pencil

    Cut mine with a fine tooth hand saw, can't remember tooth count and saw in garage and I'm far to lazy to look now

    Main thing is support the sheet really well, especially close to cut line, support off cut as well, you don't want any wobble at all.
    Gently clamp a length of timber on top of roof sheet and clamp to work bench

    Cut at a steady speed at a low angle. I got nice clean cuts, only had about 3 sheets to cut and no problems with mine

    If weather cold and roofing been stored outside, bring it in house night before to warm up a bit - cold makes it more brittle and again, support support support and NO wobble :eek:
     
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  4. Ryluer

    Ryluer Well-Known Member

    A black marker marks most plastic sheeting.

    I've cut GRP corrugated sheeting with a serrated 12" diamond blade in a con saw and worked well. Festool have a range of blades designed to cut all sorts of plastics.
     
    tore81 likes this.
  5. seen it all before

    seen it all before Active Member

    18v makita cordless grinder with a 1mm metal cutting blade. Mark with a sharpie first.
     
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  6. tore81

    tore81 Screwfix Select

    Thanks all for the tips.

    Great info.
     
  7. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    I never tried this, but how about sandwiching it between two pieces of ply, the ply having stuck to its end edge on both pieces(offset), that foam profile that is used for end blocking.
    Pressing on the ply at the cutting edge with just your cutting line on the corry sticking out, gotta be able to saw easily with normal handsaw!

    Innit?

    I normally cut it as DIYDave but with a more blunt handsaw, following the profile horizontally/vertically/angled as needed.

    Mr. HandyAndy - Really
     
    tore81 likes this.
  8. tore81

    tore81 Screwfix Select

    Ye might be worth trying that Andy. Didn't have a fine tooth saw. Next time I'll get one!

    I'll tell you what the multi tool definetly doesn't work lol. Edges looked rough but luckily hidden.
     
  9. KIAB

    KIAB Super Member

  10. tore81

    tore81 Screwfix Select

    Ok handy to know for next time.

    Thanks Kiab
     
  11. chippie244

    chippie244 Super Member

    SIAB has it right. It's easiest if the sheet is laying on an old piece of ply as it stops you from going to deep and hitting the sheet with the centre nut.
     
    tore81 likes this.
  12. sospan

    sospan Screwfix Select

  13. chippie244

    chippie244 Super Member

    A 4 1/2" grinder with a slitter blade is perfect.
    I had to cut loads last month and tried all sorts of methods and that was by far and away the quickest, easiest and most accurate.
     
    seen it all before likes this.
  14. BMC2000

    BMC2000 Screwfix Select

    What's a slitter blade exactly? I have to do a bit of this poly cutting and want to copy. Cheers
     
  15. chippie244

    chippie244 Super Member

    It's a thin angle grinder blade, lay your sheets on a sheet of sacrificial ply and crack on.
     
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  16. gas monkey

    gas monkey Well-Known Member

    Done this works perfect
     
  17. big all

    big all Screwfix Select

    old thread;)
     
  18. chippie244

    chippie244 Super Member

    That somebody wanted an answer to :cool:
     
  19. big all

    big all Screwfix Select

    yes i understand its more for information rather than accidentilly covering old ground ;)
     

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