Internal wall insulation - fixing PIR boards

[DaveH]

Hi all,

 

What options do I have for fixing foil backed PIR boards to internal masonry? I'm intending to batten over the top and screw plasterboard to the battens but what is considered best practice for fixing the PIR to the masonry? Googling and searching forums seems to give different opinions on foam or whether board adhesive will work with foil backed sheets. One of these options would be ideal as I could then cover any discrepancies in the walls so that the PIR is installed nice and flat before battening.

 

Thanks

[markc]

Use hammer in plastic fixings (Hamnmerfix) etc. makes the job really easy and maintains the insulation.

[DaveH]

17 minutes ago, markc said:

Use hammer in plastic fixings (Hamnmerfix) etc. makes the job really easy and maintains the insulation.

 

Thanks for the reply.

 

To be honest I was going to use frame fixings to fix the battens through the insulation and into the blockwork. Maybe I'm overthinking it (wouldn't be the first time!) but I was wanting something to 'glue' the insulation to the blockwork first and hopefully have a bit of give so I can make sure the sheets are nice and true as you would when installing plasterboard with dot and dab.

Edited January 12, 2021 by DaveH

[markc]

You could use expanding foam or similar as an adhesive and leveling compound prior to drilling and fixing. I wouldn't use frame fixing due to the cold bridging of the screw/nail

[DaveH]

2 minutes ago, markc said:

You could use expanding foam or similar as an adhesive and leveling compound prior to drilling and fixing. I wouldn't use frame fixing due to the cold bridging of the screw/nail

 

Thanks again.

 

Excuse my ignorance but is a frame fixing different to a plastic hammer fixing? I thought they were different names for the same item as below:

 

https://uk.rs-online.com/web/p/frame-fixings/5146577/?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Fasteners_%26_Fixings_Whoop-_-Frame+Fixings_Whoop-_-5146577&matchtype=&pla-336892306686&gclid=EAIaIQobChMIuOmqoMKW7gIVugYGAB1WeQokEAQYAyABEgJUYPD_BwE&gclsrc=aw.ds

 

https://www.screwfix.com/p/easyfix-nylon-hammer-fixings-8-x-120mm-10-pack/19157?tc=UA3&ds_kid=92700048793290424&ds_rl=1249413&gclid=EAIaIQobChMIuOmqoMKW7gIVugYGAB1WeQokEAQYBCABEgIV0PD_BwE&gclsrc=aw.ds

 

[markc]

Hi,

I prefer the all plastic hammer in fixings similar to this

https://www.tcfixings.co.uk/product/timco-m8-x-70mm-plastic-insulation-fixings-pif70-100/3361?gclid=Cj0KCQiArvX_BRCyARIsAKsnTxOjHautPssmd4i97G29ik_A4Ud8gGM4flDqSvSo8oC7w3JygGyDKA8aAk4REALw_wcB

Ordinary frame fixings cam be used, i just stayed clear of the metal inserts when i needed to fix insulation to cellar walls

[DaveH]

Got it. Thanks Mark

[jfb]

I can see how a plastic plug will hold the insulation to the wall but what is securing the battens?

[Mr Punter]

Cheap adhesive from a mastic gun just to hold the insulation in place.  Tape the joins.  Pre drill the battens so your chosen plug will fit through.  Drill through all.  Fix the whole lot with long screws into plastic plugs.