Cutting PIR board straight is harder than it looks, and the reason is that you are cutting from the wrong side. Roger meets Jody Baxter on site to look at SlideGuide, a telescopic track system that runs underneath the board rather than on top of it, so the jigsaw blade cannot wander and the cut comes out square through the full depth.
Anyone who has cut Celotex or Kingspan by hand knows the problem. You follow the line perfectly along the top, then you turn the board over and the other face has drifted off by 10mm or more. The blade flexes, the cut tapers, and on a roof or between studs that gap is the difference between a tight fit and a cold bridge stuffed with expanding foam.
Jody has been testing blades as well as guides, and the Bosch blade used here is the one giving the least dust so far, a fine tooth pattern closer to a metal cutting blade than a wood one. A longer version is in development that should produce no dust at all. Because the track mounts on the underside, blade length is not the limiting factor, only how straight the blade stays.
We also look at the SlideGuide Mini, a single track version that opens to 1300mm and has 45-degree bevels built into the wear strips, aimed squarely at roofers cutting into eaves, ridges and under layboards where the waste is enormous.
FIND OUT MORE 👇
SlideGuide
https://go.skill-builder.uk/slideguide
KEY TAKEAWAYS
• Mounting the guide on the underside of the board is what stops the blade meandering, because the cut is referenced from the face the blade exits rather than the face you can see.
• A tapered cut is caused by blade flex, not by a shaky hand, so a straight edge laid on top of the board will never fully solve it.
• A fine tooth metal cutting blade throws far less dust than a coarse soft material blade when cutting PIR and sandwiched metal roofing panels.
• The standard opening is 1118mm between the clamp pads, and releasing the thumb screws lets the telescopic rails extend to take a full length board.
• The Mini version cuts 45 degree bevels, which is where roofers waste the most board, and the clamp pads rotate so they can be set at an angle for bevel work.
WATCH NEXT
[Insulated roof panels video link]
[Loft insulation video link]
00:00 The problem with cutting PIR board
00:19 How the underside track system works
00:30 Choosing the right jigsaw blade
00:47 A longer blade with no dust at all
01:00 Dave, the millimetre perfect tradesman
01:20 Setting the opening and the clamp pads
01:47 Trimming off the damaged edge
02:02 The 40mm track saw rail
02:28 Squaring the board up in the guide
03:07 Marking 355 at both ends
03:40 The finished edge
03:57 Fitting the board between the studs
04:02 SlideGuide Mini, the single track version
04:55 Cutting a 45 degree bevel
05:39 The result and the limits of the blade
06:05 Where to buy it and the MKM rollout
Have you found a way of cutting PIR board that actually holds a line? Tell us in the comments.
#PIRBoard #Insulation #Celotex #SkillBuilder
