Best ways to route PIR boards?

Discussion in 'Eco Talk' started by TGull, Jun 9, 2018.

  1. TGull

    TGull Member

    Afternoon all,

    I'm putting some PIR boards in between my joists for underfloor heating.

    The issue I have now is routing bits out of the top... say it's 50mm deep. I need to cut say 25mm out of it where the water pipes bend around / cross the boards. So this is a mixture of shapes, not just in straight lines.

    So far I have done this with a stanley knife and it's ok, but you have to manually gouge the bits out with another knife. This creates a very messy / chunky cutting marks, as its impossible to cut in the middle. So it becomes very clumpy and inconsistent. Ideally I want the cuts to be clean so there is minimal air gaps.... I understand PIR have heat resistant properties, so that excludes any hot wires or the likes of sadly. That would have been perfect otherwise.

    Also due to the way I cut it's quite often you cut deeper than 25mm, getting close to perhaps 40mm, which is reducing the benefits of the insulation in the first place.

    Given that PIR boards prefer sharp knives to large teeth (because big teah on saws make a massive mess, and not so good for breathing in), what is the best way to do this do you think?

    I had a few ideas:
    1. Using something like the item in the bottom of this pic. This would be very messy, but I imagine it would gouge a clean route to so speak as long as you keep your hands steady -
    2. Using a router to cut it out... Once again I haven't tried this, but I imagined it will be messy.... can anyone thing of any bits which will create minimal mess e.g. cutting big chunks rather than small ones?

      I bought this router a while back but still havent used it much -
    3. Multi-tool bit - Ideally something which has a scoop. Almost like a spoon of some time which then oscillates and cuts the way forward. So far I haven't found anything like this... ideally 20mm to 22mm U shape needed for this cutting.
    4. Hand tool - something which can gouge easily though it!?!? I have a feeling this is going to be tricky though... also I imagine quite easy to go right through the boards, so no benefit there.

    Any help would be greatly appreciated, as I have a mountain of work to do still.


  2. TGull

    TGull Member

    FYI I tried using the router to cut the pipe lines.

    It was very neat but my god did it make a mess. Would not recommend regardless of the situation. I only did a couple of boards outside and it turned the whole outside with nasty white dust.

    I have gone back to using a craft knife carve shapes.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice