Cutting thickness of woodfibre board

[Jblakes]

Evening all,

Somebody in the part of the world has a number of 70mm wood fibre boards for sale, my being a tight arse are looking at them and cutting the thickness down and using as 40mm and 30mm boards.

Does anybody know it this is doable, its the steico therm multilayered boards that looks like layers of 10mm glues together. Hopefully somebody has done this before and been fine.

regards in advance
JB

 

[Cubist]

Not worth considering. You would need a large width horizontal bed band saw to do this - they can cost many thousands and few pro joinery businesses use them. It would be cheaper just to buy the new boards at the required thickness,

 

[Glenn586]

100% what @Cubist says. Even cutting them to required length is a task. Horrible things to cut.

 

[Jblakes]

Ah poo, i thought they would basically pull apart

 

[Lacan07]

No doable I'm afraid, you'll get into a right mess.

 

[Kearn]

Ah poo, i thought they would basically pull apart

They do, but that’s not a great thing. Their weakness I’ve found is in the ‘lamination’

Wood fibre on the other hand, lovely to prise apart along its length to reduce thickness.

 

[Jblakes]

These are the boards. I thought Stecio therm where wood fibre boards

 

[larry]

So I've used the Steico boards like that and it IS possible to separate them (I've done it) really carefully with a hand-saw and something long like a metal metre rule - they are basically made of 20mm sections glued together and you can carefully pull the layers apart. It's a different construction to some of the others I used which were entirely solid where of course this is impossible. However I only did this to get a small section of something thinner for a small area and wouldn't contemplate a whole room - I certainly couldn't do it without quite a lot of extra wastage and I doubt I'd get many whole boards to the right thickness.

I used the 100mm ones which were 5 layers of 20mm glued together but I've also used the 20mm ones and the 40mm ones.

What's wrong with 70mm and some extra insulation?

 

[Zebra]

I have used exactly this brand. I agree totally with Larry, you can delayer them. Especially if you are willing to destroy one half / slice in the process. It would be a fair amount of work, but not impossible.

 

[Kearn]

These are the boards. I thought Stecio therm where wood fibre boards

View attachment 15732

Ah, silly naming conventions - wood fibre batts was what I meant being easy to pull apart, rather than wood fibre boards which tend to break up in my experience - (IsoLair boards)

 

[Jblakes]

Cheers, I'll just stick that depth on the wall

 

[Zebra]

What's wrong with 70mm and some extra insulation?

Issues to consider (if using them externally) are that a thicker than anticipated board might be too proud at the eaves, gables, or window sills....

 

[Jblakes]

I was going to use them both internally and externally for small section outside View

 

[Lacan07]

These are the boards. I thought Stecio therm where wood fibre boards

View attachment 15732

This is the stuff I was referring to...not impossible to do but as I said earlier it would be difficult to achieve consistently over a full board. I used a Bahco insulation saw to cut mine.

 

[Jblakes]

how did people mount plug sockets into these boards, and rads? thinking I will need some hell of long screws.

 

[Cubist]

how did people mount plug sockets into these boards, and rads? thinking I will need some hell of long screws.

And hope the wire 'tails' are long enough to avoid using a terminal block as well.

 

[Zebra]

If mounting on top of an existing socket outlet, you could feasibly extend the cable by making a joint in the existing box using a maintenance free joint such as crimps or push-fits, then mount an extension box over the top.
If it's a new socket outlet, then a deep box mounted directly onto the substrate and long screws is the way to go.
Radiators are mounted on their own feet and screwed with long screws into the substrate but these fixings don't take the full weight.

 

[Jblakes]

if i have enough wire length, can i not just cutout 25-30mm of the insulation and sit the box within it? meaning some insulation in and around it, or is this a fire risk?

 

[Zebra]

Well you can't fix to it, so you'd still be screwing through it to the wall behind. But otherwise yes you can do that, I don't think there are any regulations against that, and any insulating effect would only be very localised, so no worse than installing a backbox in plasterboard with rockwool behind. Please remember though that cables must not be totally surrounded by insulating materials for any appreciable length, or they will be less able to carry current without overheating.

 

[Jblakes]

yeah I mean fix it through the wall, but reduce the air gap around it. Does lime plaster count as insulation? i plan to just plaster at a depth to cover them tbh.