Best method for accurately cutting Kingspan

[ggc]

So we had a ‘small’ delivery of insulation arrive yesterday

Took Mrs GGC and I the best part of two hours to move it from the driveway where it was offloaded , into the build to keep it safe and allow access.

 

Anyway 😁

As we have a touch of OCD regarding neatness and accuracy….

Whats the best diy’ers method of cutting this with minimal waste, and the best odds of accuracy without creating badly angled cuts creating less insulation against the wall timbers please ?

 

[Mr Punter]

Mask, goggles and cut with a handsaw.  I like to use a nail and a straight edge to mark the cut line on the foil face.  Foam any gaps.

[nod]

Circular saw is the quickest and will keep the edges square 

[Roundtuit]

Another vote for hand saw.  With a bit of practice, cutting at a shallow angle, you can get a consistently tight fit, and cutting square wasn't difficult. 

[SuperJohnG]

2 hours ago, nod said:

Circular saw is the quickest and will keep the edges square 

It's very quick. But defo do outside or wear goggles it's a bastard when it gets in your eyes

[RobLe]

I usually use a large kitchen knife, just to reduce dust.  It does squeal sometimes though, ear defenders!  Whether saw or knife, a wide blade helps keep the edge straight.  Japanese pull saws are thin, wide blade.

Spray a bit of water then foam gaps, the water helps foam stick.  If you use too much, leave it to set, then cut it off.

[nod]

1 hour ago, RobLe said:

I usually use a large kitchen knife, just to reduce dust.  It does squeal sometimes though, ear defenders!  Whether saw or knife, a wide blade helps keep the edge straight.  Japanese pull saws are thin, wide blade.

Spray a bit of water then foam gaps, the water helps foam stick.  If you use too much, leave it to set, then cut it off.

Just attach a Hoover 

[Bonner]

I used a jigsaw with these blades. Virtually no dust. Much easier than a knife but the blade can wander if pushed too hard. 
https://www.amazon.co.uk/Festool-Jigsaw-Blade-155-204345/dp/B07M6PKLCS/ref=asc_df_B07M6PKLCS/?tag=googshopuk-21&linkCode=df0&hvadid=412285882712&hvpos=&hvnetw=g&hvrand=2151927361750310403&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1007018&hvtargid=pla-872783453695&psc=1&th=1&psc=1&tag=&ref=&adgrpid=85363719810&hvpone=&hvptwo=&hvadid=412285882712&hvpos=&hvnetw=g&hvrand=2151927361750310403&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1007018&hvtargid=pla-872783453695

[Onoff]

I'm going to go for bfo table saw!

[Miek]

I use a hand saw.  Put the sheet on saw horses with a couple of scaffold boards to fully support the sheet underneath, then neel on top of the sheet and cut along using a straightedge as a saw guide. I find this more accurate than following a line. Oversize by 1 or 2mm when cutting for a tight fit . 

[ggc]

Well, we purchased one of these earlier today after watching a few YT videos

 

Tested it on some offcuts that were stored in the garage after having that insulated. 
Gives a very clean cut, with virtually no mess created whatsoever.

Probably going to knock up a jig of some sort to help speed up and give accurate and consistent sizes of insulation (as suggested by Robin Clevett)

Wont get a start on it until next week 🤞

 

[Onoff]

Just now, ggc said:

Well, we purchased one of these earlier today after watching a few YT videos

 

Tested it on some offcuts that were stored in the garage after having that insulated. 
Gives a very clean cut, with virtually no mess created whatsoever.

Probably going to knock up a jig of some sort to help speed up and give accurate and consistent sizes of insulation (as suggested by Robin Clevett)

Wont get a start on it until next week 🤞

 

 

I've one. I Iike the wavy edge blade idea. Not as accurate as my original Celotex pink handsaw though on say 100mm stuff. 

[scottishjohn]

8 hours ago, nod said:

Circular saw is the quickest and will keep the edges square 

especially if you have a panel saw --egwith the track bar 

[Onoff]

With PIR, however good a fit you start off with isn't there always going to be an eventual, possibly varying gap between the PIR and timber stud?

 

Guessing a spray foam like Icynene, that sticks to to the timber might accommodate such movement better? 

 

Some I believe advocate cutting the PIR 5/10mm short on the width deliberately and foam filling the whole gap width one side as an expansion thing. Is there a case for doing it both sides?

 

[Dave Jones]

Last one I just bit the bullet and bought the festool (only comp who make one?) insulation cutter with dust extraction. It runs on a track and you can do 2x 100mm sheets per pass.

 

don't forgot gapotape the edges, no bodging with foam.

 

https://gaposhop.com/shop/ols/products/gapotape-gt10-slash-100

 

good practice for complying with the new regs, pictures of everything.

[Huckleberrys]

4 hours ago, Dave Jones said:

Last one I just bit the bullet and bought the festool (only comp who make one?) insulation cutter with dust extraction. It runs on a track and you can do 2x 100mm sheets per pass.

 

don't forgot gapotape the edges, no bodging with foam.

 

https://gaposhop.com/shop/ols/products/gapotape-gt10-slash-100

 

good practice for complying with the new regs, pictures of everything.

Is the festool worth it? Better than a handsaw?

[Thorfun]

40 minutes ago, Huckleberrys said:

Is the festool worth it? Better than a handsaw?

yes (in my opinion)

[Thorfun]

5 hours ago, Dave Jones said:

Last one I just bit the bullet and bought the festool (only comp who make one?) insulation cutter with dust extraction. It runs on a track and you can do 2x 100mm sheets per pass.

+1

[Dave Jones]

1 hour ago, Huckleberrys said:

Is the festool worth it? Better than a handsaw?

 

2 words. dust extraction.

[crispy_wafer]

1 hour ago, Huckleberrys said:

Is the festool worth it? Better than a handsaw?

Absolutely, either buy rails, or use a straight edge and clamps, keep it in good condition, wipe/brush or air blow it clean it after use and you will sell it for not much less than you paid for it when finished.

 

Essential for cutting the edges true, Gapotape is OK as it allows you a few mm of leeway, I used a couple of boxes of gapotape, then went cutting onto flush and inteference fit when I ran out.