Celcon Foundation Blocks

[realtek]

Hi,

I've used two courses of Celcon foundation blocks to get me up to a good ground level for a conservatory dwarf wall.

However, I assumed because they could be used below DPC that they could be used above ground. I did not think about frost being new to these.

Basically, in the worst area I have almost whole foundation blocks showing.

Is this a major concern (i.e should I remove the second course and use something else) or will it be sufficient to render down the just below ground level and that will be enough to protect them?

Thanks

 

[cjard]

The frost is only a problem if it gets wet: When the water freezes it expands and chips the block. After some time the ground would be covered in trench block dust. If you can ensure that water in the block doesn't freeze it won't happen..

 

[^woody^]

The frost is only a problem if it gets wet:

Unless the OP is building a conservatory in the Sahara, then a foundation block is going to get wet.

I suspect that 95% winter humidity, a rapid temperature drop, and an air frost may also have an impact.

Is this a major concern

I thought all this was mentioned in your original thread several weeks ago? ie don't use these blocks in that location

 

[realtek]

Thanks woody. Yes it as mentioned a few weeks back. Perhaps I miss understood. I thought we were talking about celcon Foundation blocks full stop. I didn't realise we meant just at ground level. Expensive mistake on my part!

Perhaps it would be wiser to demolish the second course and just have the one course below ground. I have some dense concrete blocks turning up tomorrow so I can use them in its place. Only £50 down the drain but a lot of time and a set back but hey could have been worse

 

[realtek]

Woody, are celcon ok on the inside skin below dpc or shall i just use concrete blocks for all below dpc?

Only asking because I will have enough to do the lot but if it's not recommended I will avoid

Thanks