What fixing for sink into insulated plasterboard
What fixing for sink into insulated plasterboard
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dba7108

Original Poster:

675 posts

191 months

Sunday 14th September 2025
quotequote all
What is the best fixing for a small cloakroom basin sink. Porcelain tile onto insulated "insulated qboard basiq". Behind this is breeze block. The sink has come with a fischer type bolt but maybe I need to get a much longer one?


wolfracesonic

8,899 posts

150 months

Sunday 14th September 2025
quotequote all
Google ‘Rigifix’ fixings; if the blocks are really crumbly types, undersizing the drill hole by .5mm can sometimes give a stronger fixing.

Pheo

3,496 posts

225 months

Sunday 14th September 2025
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Corefix is probably what I’d be using into the blocks behind

LooneyTunes

9,017 posts

181 months

Sunday 14th September 2025
quotequote all
Cut a section out and fit a wooden patress then through that with pretty much any plug/screw combination that is long enough and strong enough to make it into the block.

fat80b

3,179 posts

244 months

Sunday 14th September 2025
quotequote all
Pheo said:
Corefix is probably what I d be using into the blocks behind
I had to hang a rad the other week onto plasterboard, gap then brick.

I used the Resin stuff R Kem from Screwfix in the hole as well as the corefix plugs.

It’s solid as a rock and supporting quite a weight.

119

17,282 posts

59 months

Sunday 14th September 2025
quotequote all
If its a pedestal type, i have just used normal plugs and screws into the block, with a thin bead of silicone around the back face of the sink around an inch in from the edge.

Haven t had one fail (yet!).

OutInTheShed

13,114 posts

49 months

Sunday 14th September 2025
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If there is block behind the plasterboard, then I would fix into the block and use a spacer or rigid filler to avoid compressing the plasterboard.
Many ways of doing this, doesn't matter so much which you use, so long as you do it right.


Plasterboard is surprisingly strong for forces acting straight down the sheet.
Forces pushing into the face or pulling out, not so much.

dba7108

Original Poster:

675 posts

191 months

Sunday 14th September 2025
quotequote all
Thanks for replies. It's a wall sink and I'm guessing my concern was that the breezeblock is quite crumbly. I'm going to try the fixing above with the resin I think that will be the most solid.

POIDH

2,955 posts

88 months

Sunday 14th September 2025
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With a (wood fibre) internally insulated wall before I 'chased in' a couple of wood battens down to the floor and replaced plasterboard with ply, 'legs' held back to stone wall with two very long Fischer fixings. Then tiles over the top to hide it all.

dba7108

Original Poster:

675 posts

191 months

Monday 15th September 2025
quotequote all
Is FIS V zero (fischer) ok as an injection ? Thanks