Conservatory dwarf walls. Do these look right?

Rural_Puppy

Hello all
Had a bit of a nightmare with our builder. Long story.
Short(er) version: We have parted company with our builder part way through a conservatory build. The conservatory was purchased as a supply only from manufacturer.
It's about 3m x 3m lean to with glazed roof.
The dwarf walls are up and concrete slab laid. My worry is that the walls are not as we expected and may not be appropriate. Spec was 600mm wall to be constructed of 4 X 150mm blocks to be rendered externally. Internal wall and floor to be insulated. Internal leaf to be timber kit with cavity.
Issues:
1. Outside leaf is built of a mix of bricks and blocks. The lower course of bricks indicates the damp course. But why so many bricks in the upper courses and of different types? Some red, some white and some split blocks. (Suspect he ran out of blocks, and didn't want to own up.) Will this affect strength of wall?
Have the red bricks been set the wrong way round with the smooth side facing the render rather than the rough face?
Outer wall  is laid on foundations of poured concrete 350mm thick. Is that enough?
2. Inner leaf is 4 blocks high ie 600mm with no bricks, so must be built off a different higher foundation level. It has got a separate DPM that is laid beneath the concrete slab.
We were expecting inner wall to be timber kit to maximise space inside, as conservatory panels will sit on outer leaf.
3. There are no wall ties. Is this ok as wall is low at 600mm high?
4. The electricity supply cable is buried under the concrete foundations. This is newly laid and was supposed to run around the walls, not underneath. Cable has been pulled from outside and is now tight against the meter inside.

Basically I am concerned that the walls as built may not be sufficient to hold the conservatory up.
Can anyone assist before I find another contractor and ask them to demolish and start again?
Thank you 

stuart45

Unfortunately conservatory bases are often poorly constructed. However the mix of materials won't really affect the strength of the wall. 

Doozergirl

I get it if someone has given a strict and sensible spec and a builder hasn't followed it, but I don't understand the spec.   Who created it?  

As above, the vast majority of conservatories aren't built to the building regulations, they are cheap for a reason.  If the objective is to build them even more cheaply.... 

150mm isn't the height of a block.  Blocks are 215mm high.  You get 140mm depth blocks,
but if you lay them on side + 10mm
mortar, you get a solid 215 wall. 

I don't really understand what you've specced or what they've built but it looks like the result of some strange conversations.  

Rural_Puppy

Thanks for the replies. Part of the reason we parted company with the builder is because he didn't like written specs......we found that very odd. In retrospect, one of several red flags. You live and learn.
Doozergirl, you are quite right, the spec arose from various on site conversations. We knew the height of the wall and that it needed a cavity and to be insulated. We knew we wanted a concrete floor with same finished level as inside house. We did not know how to build it (we aren't builders!).
The builder said: well to avoid lots of cutting I will make it 4 blocks high to give the 600mm. Made sense at the time.... and no mention of bricks.
He added that "we will dig down to ensure we get the correct height overall." To be fair, the inner leaf is built like that with 4 complete blocks, but we had expected that to be timber kit....so we wonder if he somehow miscalculated measurements and that leaf was originally meant to be the outer one??
Anyway, we now need to decide whether we can safely proceed with what we have per the questions above.
we currently have a pond developing outside our house, so any assistance that anyone can offer would be gratefully received! TIA.

stuart45

The bricks aren't a problem, although they would have been better at the bottom so the inner and outer skins would line up for a few wall ties. I'm guessing that there is insulation and screed to go on the floor yet, so you will be getting some ponding at the moment. The walls can also be insulated later. 

Rural_Puppy

Are wall ties necessary?

Rural_Puppy

Oh and he argued with us about insulation, said there was no point.....

stuart45

They normally go in every second course of blocks, or every course at the jambs. 6 and 3 for brickwork. Your walls aren't very high, so a few missing ties will probably not be a problem. It's mainly on houses, especially the gable ends where the lack of ties is a problem. They sometimes get forgotten on site and the hod carrier scrapes a bit of mortar out at the back and sticks them in, but they are never the same as being built in. 
I wouldn't worry too much, ties can be retro fitted if needed. 
I guess the original spec was for 6 inch blocks on their side and the inside battened out and plasterboard. What you have is a standard cavity wall for a conservatory. Cavity batts could be slid down for insulation.

Ectophile

Rural_Puppy said:

Oh and he argued with us about insulation, said there was no point.....

You're putting in a lean-to greenhouse with a fancy name.  I don't suppose cavity wall insulation will make much difference.  Most conservatories don't meet building regs anyway.

williamgriffin

The DPC is at ground level on one side, are you going to be removing and earth to drop the ground level?

Rural_Puppy

Ectophile said:

Rural_Puppy said:

Oh and he argued with us about insulation, said there was no point.....

You're putting in a lean-to greenhouse with a fancy name.  I don't suppose cavity wall insulation will make much difference.  Most conservatories don't meet building regs anyway.

Our thinking is that insulation in the floor and walls will help regulate inside temperature a bit. The reason he argued is because he had not dug out the floor deep enough for the rigid insulation to go in. He finally agreed to dig it out further before laying the cement floor.