Trench block or cavity with infill below DPC advice required?

[Canski]

7 minutes ago, ruggers said:

My joists are going on internal masonry hangers. Door and window reveals say they need a wall tie every 225mm so they'll need slit to.

Tada !! yes they need to be slit too. More delamination 

[Mr Punter]

I have used full fill rigid t&g insulation before.  It was often a struggle to get the bricklayers to fit them the correct way up.  Luckily it was just ground floor with timber frame and cladding above so not so much hassle with coursing.

[Dave Jones]

best bang for your buck buildup. Use EPS under the screed not far from half the price of celotex for a superior U value. Here is what we use working FFL down. 

 

         external                      Internal

             damp                   damp

75mm   eng                      75mm screed

75mm   eng

225mm 7n block              300mm EPS insulation

225mm 7n block              150mm beam

                                          75mm conc common

 

total build up 600mm / 600

 

dont forget to use thermally broken marmox blocks as the first course of inner skin.

[ruggers]

@Dave JonesThanks Dave, whats the difference with the marmox blocks and a celcon/aircrete/thermalite block for the first course? I was going to run a course of them round before I build my inner walls with normal block on top. The marmox looks very expensive.
 

I had a look at EPS and I'd need 240mm to equate to 160/165mm PIR. The saving was £700 but by the time I'v bought the extra course of bricks and paid the labour it just works out the same. 

[MikeGrahamT21]

1 hour ago, ruggers said:

@Dave JonesThanks Dave, whats the difference with the marmox blocks and a celcon/aircrete/thermalite block for the first course? I was going to run a course of them round before I build my inner walls with normal block on top. The marmox looks very expensive.
 

I had a look at EPS and I'd need 240mm to equate to 160/165mm PIR. The saving was £700 but by the time I'v bought the extra course of bricks and paid the labour it just works out the same. 

 

Marmox Thermoblocks are essentially XPS with concrete reinforcement in them, where aircrete blocks are 0.11W/mK marmox is 0.047W/mK

 

https://www.marmox.co.uk/products/thermoblock

[ruggers]

Thanks a big difference in U-Value, I wouldn't mind a house built from them if I wasn't paying for it.

[MikeGrahamT21]

Isn't that just a house constructed from SIPS or ICF? 😂

[ruggers]

I didn't think sips was that low, thought it's just PIR of a certain thickness in structural panels for fire it up quick. 

I've never looked into it much due it it being fairly expensive but I think it's a great way to build if you can afford it.