Which mushroom fitting is better?Metal or plastic.

eamon11

Hello Folks,

I wonder if any of you have an opinion on this.

I am internally slabbing and wonder is metal or plastic mushroom fittings better?
Insulated slab 62mm thick.

Thanks a lot

DublinDilbert

eamon11 wrote: »

Hello Folks,

I wonder if any of you have an opinion on this.

I am internally slabbing and wonder is metal or plastic mushroom fittings better?
Insulated slab 62mm thick.

Thanks a lot

You'll get mixed responses. The metal ones do grab better and I've heard plasters prefer them. But some people say the metal ones can cause cold spots on the wall where moisture can condense and get mouldy.

I've used both, it does feel like the metal ones hold better.

Robbie.G

DublinDilbert wrote: »

You'll get mixed responses. The metal ones do grab better and I've heard plasters prefer them. But some people say the metal ones can cause cold spots on the wall where moisture can condense and get mouldy.

I've used both, it does feel like the metal ones hold better.

I've seen the metal ones cause mould but that was because they drilled through the internal block and into the cavity so cold air was blowing up through the fixing.
If you use the metal type use a dept stop on your drill and make sure you don't drill through the internal block

TheLastMohican

The metal ones can cause cold bridging. I did it into cavity blocks on a 1950s extension. This caused condensation when the shower was being used. After a year or so I stuck warmboard on top and reskimmed. Have not used metal since. But they as easier to fit.

eamon11

thanks a lot lads,

I have heard something similar. The wall is a 14 inch solid concrete wall. 1940 bungalow. So because there is no cavity block, might the metal ones be ok?

Bonzo Delaney

I've used the metal ones on hollow block. To stop the head of the fixing showing through after fixing ive painted the heads with zinsser bin primer/sealer paint. It's worked every time.