Light or solid dense concrete block?

[Mcneelyma]

I'm hoping for some more advice regarding which block to use, i've had a look around but not really got a good explanation of which block i should use. I've used solid dense for founds and 3 inner course above ground level. Its a 100mm partial fill cavity.

Should i now use lighweight 7n blocks from here on? I know there lighter but is there any structual difference between them and the heavier ones that i've been using? These will be rendered as i have facing brick outer course so far.
I'm hoping to order them shortly, whats the advantages and disadvantages?

 

[Mcneelyma]

Also, are these 'lightweight' blocks the 7n aerated ones which can be rendered? Can they be mixed with solid dense?

 

[noseall]

Use 3.5n fibolites, hemelites or similar.

 

[Mcneelyma]

Are they the lightweight blocks? Are the solid dense overkill for this project and can the 3.5N be mixed with the solids?

 

[noseall]

Yes you can throw in some solid dense fellas externally but use these at the bottom.

 

[Mcneelyma]

Bear in mind this is a diy project, why use the 3.5N at the bottom? Sorry for the repeated questions but the builders merchant said to use lightweight 7.n for ease, is he trying to get a sale? I've ordered solids so i should change these to fibrolites, are they similar in texture? Never used them before....
Thanks fo the replys

 

[noseall]

If it were me i would want a uniform suction background for the rendering, therefore i would use all the same block.

I would also want to be using a well keyed, moderate suction, light-weight block i.e 3.5n fibolite/hemelite type block.

I would prefer the lightweight blocks so that i could lay lots of courses in one day without the wall buckling....or me buckling due to lifting 7n dense solids.

Bear in mind this is a diy project, why use the 3.5N at the bottom?

Thats not what i said. I said use the dense solids at the bottom.

 

[Mcneelyma]

I would prefer the lightweight blocks so that i could lay lots of courses in one day without the wall buckling....or me buckling due to lifting 7n dense solids.

Bear in mind this is a diy project, why use the 3.5N at the bottom?

Thats not what i said. I said use the dense solids at the bottom.

appoligies about the mis-interpretation.

Thats sounds like a plan to me , i dont fancy killing myself with those big heavy lump blocks,what about the lightweight 7N i mention what are these blocks or are they the same as u mentioned?

The roof load is going to have attic trusses, will the lightweights be ideal for the 'load bearing' walls?

Thanks again

 

[noseall]

No probs regards load bearing, though you will likely need pad's for any structural steel point loads.

 

[Mcneelyma]

Thanks again for some good advice, i'll order the lightweight block in the morning, my back will thank me for it lol. i'll be using l5/100 cavity lintels so i'll search the net and look for pads to suit.

 

[noseall]

Thanks again for some good advice, i'll order the lightweight block in the morning, my back will thank me for it lol. i'll be using l5/100 cavity lintels so i'll search the net and look for pads to suit.

You won't need to use pad's for proprietary manufactured lintels only for steel beams etc.