Rigid PIR boards in cavity Walls. DON'T DO IT.

[Iceverge]

I had a look at a new site recently. Good job was done on the blockwork I thought.

 

The PIR Was installed in the usual fashion, far far from the worst I've seen mind you. Gaps between boards, wall ties not fitting correctly, mortar droppings on the boards etc. 

 

I maintain it cannot be accomplished to a satisfactory standard in real life and shouldn't be attempted. Bonded EPS beads or mineral wool batts are far superior. 

 

 

 

Edited April 13 by Iceverge

[Iceverge]

 

 

[Iceverge]

 

 

[Iceverge]

 

[Iceverge]

[ProDave]

And I bet the builders will be saying what a good job, a nice insulated house.....

[nod]

A lot of sites now blow the beads in afterwards 

But even these tend to settle Or end up und the Block and beam 

[G and J]

I'm told, and I believe it, that when selling a house telling the world it’s a self build is taken as a big negative - peeps would much rather have professionally built houses.   My guess would be the above would be less likely in a self build where the self is actively involved in the build.  Odd world innit.

[Mr Punter]

It looks like some of the board was used in the outer leaf!

 

[Nickfromwales]

  On 13/04/2025 at 14:12, Mr Punter said:

It looks like some of the board was used in the outer leaf!

 

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Yup. I was wondering how they got hold of load bearing PIR……

 

I think the block layer has gone rouge here.   

[Mattg4321]

He certainly will be rouge when it’s pointed out to him, if he’s got any pride that is. 

[Nickfromwales]

  On 13/04/2025 at 14:35, Mattg4321 said:

He certainly will be rouge when it’s pointed out to him, if he’s got any pride that is. 

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Just terrifying tbh, wtf was he thinking?!

[ProDave]

  On 13/04/2025 at 13:23, Iceverge said:

 

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I see he's used "structural PIR" at both ends.

[Canski]

  On 13/04/2025 at 14:12, Mr Punter said:

It looks like some of the board was used in the outer leaf!

 

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They may have stone cills to install afterwards and are using insulation as a prop for the blockwork.  There will be a reason. 

[Declan52]

  On 13/04/2025 at 14:12, Mr Punter said:

It looks like some of the board was used in the outer leaf!

 

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You do the same thing when your leaving the cills out to be put in later on to prevent damage. I assume some sort of door threshold will be installed at a later date.

[Iceverge]

At a guess I think this if for an external precast threshold. 

 

I'll keep an eye when I'm passing.

 

It's a shame the boards are used. It's a generally well done site otherwise. 

[jack]

A recent build near me uses the same boards as these.

 

The inner leaf was built several rows ahead of the outer leaf. No snots. Boards installed flat against the inner leaf, with all joints foamed and taped. 

 

It's frustrating that this is notable. It should be standard practice.

[tuftythesquirrel]

  On 13/04/2025 at 14:00, G and J said:

I'm told, and I believe it, that when selling a house telling the world it’s a self build is taken as a big negative - peeps would much rather have professionally built houses.

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Hi, Give me a hands-on self-builder, with OCD any day 😜

[MikeGrahamT21]

I totally agree with most of the PIR products, but still think this one is head above the rest with its engineered parts that prevent a lot of the issues mentioned: https://unilininsulation.co.uk/products/cavitytherm/ct-pir-cavitytherm/

 

This is also the only system with purpose made components for different areas of the build, not relying on someone cutting them by hand and cocking it up

Edited April 14 by MikeGrahamT21

[Canski]

  On 14/04/2025 at 07:54, MikeGrahamT21 said:

I totally agree with most of the PIR products, but still think this one is head above the rest with its engineered parts that prevent a lot of the issues mentioned: https://unilininsulation.co.uk/products/cavitytherm/ct-pir-cavitytherm/

 

This is also the only system with purpose made components for different areas of the build, not relying on someone cutting them by hand and cocking it up

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I’m sorry but that is the worst insulation system that I have ever used for so many reasons. Xtratherm used to have a similar product maybe they just changed the name. 

[MikeGrahamT21]

  On 14/04/2025 at 15:59, Canski said:

I’m sorry but that is the worst insulation system that I have ever used for so many reasons. Xtratherm used to have a similar product maybe they just changed the name. 

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It’s the same one, they rebranded to unilin.

 

care to elaborate on why you didn’t like it? By far the best system I’ve come across and used