How should I cut Kingspan insulated dry-lining board?
DavidA
I need to cut some Kingspan Kooltherm K17 dry-lining board. I want to
make a really nice job of it so that it s not necessary to skim-
plaster it when its mounted on the wall.
Kingspan's cutting advice is:
"Cutting should be carried out either by using a fine toothed saw, or
by using a sharp knife to cut through the insulation and paper backing
of the plasterboard, then snapping the board face down over a straight
edge and cutting the paper facing of the plasterboard on the other
side. Ensure accurate trimming to achieve close butting joints and
continuity of insulation."
I am not sure I understand this. Presumably its necessary to cut
through not just the insulation but part-way through the board itself,
if one stands any chance of snapping it. I don't know how I would do
that.
Please can anyone give me advice on the best way of doing this?
BR
David
stuart noble
I'd cut straight through with a saw, plaster uppermost. The plaster will
blunt it pretty quickly so use any old saw you have lying around and
take it slowly to avoid tearing the paper. If it's anything like the
standard foam boards, a sharp knife is not a good method, but anything
with teeth just glides through it.
d...@gglz.com
Best tool I found was one of those snap-off blade knives - so I could
extend it right out to go through 50mm kingspan in one go - with a
sawing action. A steak knife is almost as good. Use a straight edge.
Then like they say, snap along the line - it jut releases any little
bits you missed. Finally score through the backing paper, which is a
little tough to get right through with the first pass that went right
through the board.
d...@gglz.com
I had read it.
DavidA
> Sorry, you were describing kingspan backed PB, not plain kingspan - as
> I had read it.
K17 is plasterboard with insulation on the back.
I still don't understand the snapping part - surely the plaster board
part is pretty tough. Do I have to cut part way through that before
snapping?
Franko
"DavidA" <dand...@talktalk.net> wrote in message
news:0117be4f-22ee-4655...@s50g2000hsb.googlegroups.com...
As with most types of plasterboard - you only need to score, albeit quite
deeply, the first layer of paper, the board will then snap along the
weakest point when you apply pressure - as long as you have scored deeply
enough then it will snap quite cleanly along the line.
The main thing that gives plasterboard its strength is the paper bonded to
each side, without the paper it is just brittle plaster.
You then fold the board back on itself and follow the score on the other
side with a stanley knife.
You may need to tidy up the cut side with a surform or carefully with a
stanley knife but most often the cut will be tidy enough as it is.
Franko.
Dave Liquorice
> I still don't understand the snapping part - surely the plaster board
> part is pretty tough. Do I have to cut part way through that before
> snapping?
Plaster is pretty weak, most of the strength of plasterboard comes from
the paper on each face. The instructions are fairly clear, IMHO.
You cut through the insulation *and* right through the paper between the
plaster core and insulation. Place the board face down (insulation and cut
up) along a straight batten an inch or two high aligned with the cut and
if the bit suspened is of a decent size it's weight will be enough snap
the plaster. So you should have placed the board face down along the
batten first, with both sides of the cut supported... You then need to cut
through the paper on the face side, this might be the hard part as the
weight of the plaster/insulation may well try to tear the paper away from
the plaster core.
Personally I've used a stanley saw blade in a knife handle, 57220 or 20862
(for finer teeth, not used that) from Screwfix. They also have a wall
board saw 36570 but that looks a bit vicious and doesn't have a
replaceable blade(?).
In your OP you also said:
> I want to make a really nice job of it so that it s not necessary to
> skim-plaster it when its mounted on the wall.
How are you proposing to fill the joints? They need to be taped or they
will crack with normal building movement. I can't think of way that you
can just but join edges without having to skim over the tape to cover it.
You can get featheredge insulated board and the tape sits in the feather
and you just skim/fill the feather rather than the entire wall.
--
Cheers
Dave.
Geo
<allsortsn...@howhill.com> wrote:
>Personally I've used a stanley saw blade in a knife handle, 57220 or 20862
>(for finer teeth, not used that) from Screwfix. They also have a wall
>board saw 36570 but that looks a bit vicious and doesn't have a
>replaceable blade(?).
Very coarse (7tpi) - used it once then went back to the stanley knife saw.
Geo