What fixing for sink into insulated plasterboard
What fixing for sink into insulated plasterboard
Author
Discussion

dba7108

Original Poster:

675 posts

189 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

8,704 posts

148 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

3,494 posts

223 months

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

LooneyTunes

8,700 posts

179 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

3,134 posts

242 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

16,072 posts

57 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

12,686 posts

47 months

Sunday 14th September 2025
quotequote all
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

189 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

2,565 posts

86 months

Sunday 14th September 2025
quotequote all
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

189 months

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