Which block to use

[RonnyRaygun]

You don't need to employ anyone.

Just give Celcon a call. They will advise you of what you need to comply with current regs.

Probably 200mm blocks with 80mm internal insulation wouldn't be far off the mark.

I doubt you are going to comply with regs with 40mm insulation (does the 40mm include the plasterboard?)

 

[mcluma]

My appologies i had overlooked something on the specsheet from Celcon

I checked it again

the spec sheet says

a 300 wide solid block (no cavity)
16mm render outside
30mm thermalite basic inside
gives a 0.3 U value

 

[wavetrain]

Steady on wavetrain, there are ways and means you know!

Am I getting grumpy in my old age?

 

[wavetrain]

My appologies i had overlooked something on the specsheet from Celcon

I checked it again

the spec sheet says

a 300 wide solid block (no cavity)
16mm render outside
30mm thermalite basic inside
gives a 0.3 U value

Not with a Celcon Standard will you get 0.3 U value, maybe with a Solar, but you cannot get render to stick to a Solar unless you are lucky so builders lore goes. And you wrote you were going for a Standard. You are changing your rules as you go on.

Are you by chance one of forum user diy001's aliases?

 

[mcluma]

My appologies i had overlooked something on the specsheet from Celcon

I checked it again

the spec sheet says

a 300 wide solid block (no cavity)
16mm render outside
30mm thermalite basic inside
gives a 0.3 U value

Not with a Celcon Standard will you get 0.3 U value, maybe with a Solar, but you cannot get render to stick to a Solar unless you are lucky so builders lore goes. And you wrote you were going for a Standard. You are changing your rules as you go on.

Are you by chance one of forum user diy001's aliases?

You are right about the solarblock - wel spotted

so the grooves on the outside will not help the render (isn't that the hole point of the grooves so the render stick best)

Wavetrain,
So rather telling me what cannot be done, what would you recommend as a solid block in combination with a 40mm insulated plasterboard

 

[freddiemercurystwin]

My appologies i had overlooked something on the specsheet from Celcon

I checked it again

the spec sheet says

a 300 wide solid block (no cavity)
16mm render outside
30mm thermalite basic inside
gives a 0.3 U value

Not with a Celcon Standard will you get 0.3 U value, maybe with a Solar, but you cannot get render to stick to a Solar unless you are lucky so builders lore goes. And you wrote you were going for a Standard. You are changing your rules as you go on.

Are you by chance one of forum user diy001's aliases?

You are getting increasingly grumpy and a bit blind in your old age too, anyhoo its irelavant anyway the U value required for extension walls is 0.28.

To estbalish exactly what you need, contact your eventual insulation supplier be it Celotex, Kingspan or British Gypsum or whoever and ask them to do the calc, they'll send you a PDF you can stick under the nose of Building Control.

Celotex have a handy U value calculator that's free and easy to use.

 

[wavetrain]

n
You are getting increasingly grumpy and a bit blind in your old age too

Pot calling the kettle black! Who was it who took down his posted detail in a hissy fit a few weeks back because the intended recipient did not thank you within 24 hours?

 

[freddiemercurystwin]

But I've always been this grumpy!

 

[mcluma]

That calculator is really handy

Thanks

 

[stuart45]

There have been a number of houses built in recent years using 300mm blockwork with a thin joint system.
www.masonryfirst.co.uk/pdf/Thin-Joint system brochure-85.pdf

 

[theoldun]

Tell yer what wave train, Freddy boy may be grumpy he may even be obnoxious and argumentative at times, but we always respect his posts, respect his knowledge and respect the way he is one of the first to help people out with free advice.

Why not answer the OPs question and tell him what to do and what to use instead of telling him what not to do and what not to use.

mcluma. You are making heavy going on your proposed method, if you have not got yourself sorted out by now, come back and we will tell you the best way to achieve the new 0.28.
oldun

 

[hotrod]

But I've always been this grumpy!

Ain't ya just Fred !

View media item 15294

mcluma - a bit of advice if I may, 'KISS and buildability'. 100/100/100 all the way if you're not familiar with construction methods stick to tried and tested designs, methods, details and materials that are readily availible at a competitive cost and without daft lead times.

 

[wavetrain]

Tell yer what Old un, I would not build a solid wall for 0.28 as I don't like the lightweight structures that result, but as the OP would not hear of a cavity wall construction with heavier weight load bearing materials, all I could do is point out his mistakes so he doesn't end up with a U value too high to pass BC.

As you can see, I'm not an augmentative person.

 

[noseall]

300mm thick solid blockwork with pants insulation on the inside!!!

FFS whatever next!

As stated 100/100/100 every time.

Who in their right mind would opt for fitting insulation to the inner wall surface, when there are simpler options, needs their head looking at.

 

[wavetrain]

As you can see, I really am not an augmentative person.