Conservatory dwarf walls. Do these look right?

Rural_Puppy

williamgriffin said:

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

Probably. If we eventually get the thing built, the plan is to have gravel running along the outside of the walls below the dpc. ETA: the dpc is running along the top of the lower brick course.

williamgriffin

Rural_Puppy said:

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.  

Not enough to prevent it being too hot in summer and too cold in winter. 

williamgriffin

Rural_Puppy said:

williamgriffin said:

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

Probably. If we eventually get the thing built, the plan is to have gravel running along the outside of the walls below the dpc. ETA: the dpc is running along the top of the lower brick course.

The DPC should be 150mm above the ground so your builder has gone wrong there. 

stuart45

Have you paid him yet?

Rural_Puppy

stuart45 said:

Have you paid him yet?

No!

Rural_Puppy

Thanks all. From the responses:
1. The original spec may have been wonky. We expected 4 blocks high set on their sides, rendered externally with timber kit inner leaf.
2. Not ideal to have different materials in the construction of the outer wall, but unlikely to affect wall strength. Will it take render though, as the bricks' smooth side is facing out?
3. Wall ties would have been preferable, but not essential as it is a low wall.
4. The dpc is too close to the ground level.
However..... I am still concerned that the outer wall may not be strong enough to bear the weight of the structure, and also that dampness may be an issue.
There are two sets of dpc, one above the lower brick course, and the other beneath the floor slab.
We are also worried about the buried electricity supply cable.
Our options are:
A. Demolish entire thing and start again.
B. Remove inner walls and replace with timber kit.
C. Continue to build off this structure and hope for the best.

We have parted company with the builder due to him consistently failing to follow our instructions and cutting corners at almost every stage. Finding an alternative and decent tradesman to take on his (possibly faulty) work for the conservatory base may be difficult.
What would you do in our shoes?
Thank you!

tonyh66

Nothing wrong with building a conservatory off a cavity wall, the only problem I can see with yours is the DPC on the outer wall is too low (I can't actually see it on the pictures) golden rule is 2 bricks above ground level.

stuart45

Rural_Puppy said:

Thanks all. From the responses:
1. The original spec may have been wonky. We expected 4 blocks high set on their sides, rendered externally with timber kit inner leaf.
2. Not ideal to have different materials in the construction of the outer wall, but unlikely to affect wall strength. Will it take render though, as the bricks' smooth side is facing out?
It will take the render. If there is ever a problem with a material a bonding agent can usually be applied.
3. Wall ties would have been preferable, but not essential as it is a low wall.

4. The dpc is too close to the ground level.
Can your ground level be lowered.
However..... I am still concerned that the outer wall may not be strong enough to bear the weight of the structure, and also that dampness may be an issue.
There are two sets of dpc, one above the lower brick course, and the other beneath the floor slab.
We are also worried about the buried electricity supply cable.
Our options are:
A. Demolish entire thing and start again.
B. Remove inner walls and replace with timber kit.
C. Continue to build off this structure and hope for the best.
If the measurements are correct and the foundation was deep enough I would carry on with the build.

We have parted company with the builder due to him consistently failing to follow our instructions and cutting corners at almost every stage. Finding an alternative and decent tradesman to take on his (possibly faulty) work for the conservatory base may be difficult.
What would you do in our shoes?
Thank you!

Just my opinion.

FreeBear

A conservatory isn't a particularly heavy structure. The walls you have there will be more than adequate.

As for cabling - It should be at least 50mm below the finished surface and even better if run through some steel conduit that is earthed. Being in conduit makes life much easier should the cable ever need replacing.

Rural_Puppy

Thanks again for replies much appreciated. A few more questions:
1. How do we know the foundations are deep enough? We think there is a 350mm cement strip foundation. Not sure how deep down. There is then a line of cement blocks on their sides sitting on top, then the course of orange bricks, then the dpc strip.
2. The conservatory has a glass roof which will add to the weight. It is also in quite an exposed location for prevailing winds. Hence our concern at later failure if the walls aren't strong enough.
3. Very worried about the electricity supply cable. I think it has been buried in the cement floor slab. Nothing sensible like a conduit to protect it. This might be one for the electric co to look at. They laid it fairly recently and were warned of the planned location of the conservatory and to run the supply cable around the outside. It appears that that did not happen. 
What started off as a nice entrance porch with space for sit ootery has turned into a complete nightmare!! We want to do the right thing to fix it, but just aren't sure quite what the right thing is. Thank you.