When a wall needs to be lightweight blocks downstairs and concrete upstairs?

[vincentianpinner]

I'm talking about the internal wall in a porch. Which becomes an external wall on the first floor. As there needs to be a tray to keep rain from entering the cavity just about the flat roof is that a point where you can change the type of block?

 

[davidmiller]

Have you started yet? I think I'd do the porch inner walls with concrete blocks. Solves that issue and not a lot of difference regarding warmth.

 

[^woody^]

"Needs to be"?

You would not normally do this

 

[vincentianpinner]

"Needs to be"?

You would not normally do this

Yes there is a tray going in. Do you know if it can be a roll of wide dpc or the individual hard plastic ones?
I think I will do the other suggestion also, medium concrete blocks on inner wall of porch.

 

[vincentianpinner]

Have you started yet? I think I'd do the porch inner walls with concrete blocks. Solves that issue and not a lot of difference regarding warmth.

Yes I might do that. Cheers

 

[^woody^]

Yes there is a tray going in. Do you know if it can be a roll of wide dpc or the individual hard plastic ones?
I think I will do the other suggestion also, medium concrete blocks on inner wall of porch.

450mm wide DPC, polyethylene or the rubber (polymeric) type but not the bitumen type.

 

[vincentianpinner]

450mm wide DPC, polyethylene or the rubber (polymeric) type but not the bitumen type.

Thanks very much. I assume I can't cut a mitre to do a corner and something else is needed there?

 

[^woody^]

Yes you can form it, and tape it if need be

 

[vincentianpinner]

Yes you can form it, and tape it if need be

Nice one.

 

[Markbon]

Just a word of caution, and I'm no expert but I've heard that if you have different materials on an internal cavity wall then moisture can collect in the cavity. If it's different on both sides of the cavity I mean.

 

[vincentianpinner]

Ok. Thanks. Not sure what to do but thanks

 

[vincentianpinner]

Just a word of caution, and I'm no expert but I've heard that if you have different materials on an internal cavity wall then moisture can collect in the cavity. If it's different on both sides of the cavity I mean.

 

[Markbon]

Ok. Thanks. Not sure what to do but thanks

As you mentioned a dpc will separate them. Also I think I've seen ex-met in the bed joints between the different blocks to help this. Not sure it's the answer but I think it might be.