Construction and engineering questions

Hannaho

Just wondering what should an engineer look out for with pre and post concrete pouring? What does he examine? What tests should an engineer preform before foundations are poured. Should the engineer get the pyrite and foundations certificates at these times from the builder? Would an engineer be able to spot that their were no foundations under an extension that was being knocked and rebuilt?

Also, if building over a drain - Council drain running through back gardens - what should tests should the engineer take - how does he ensure that the drain is built over correctly?

Gumbo

Hannaho wrote: »

Just wondering what should an engineer look out for with pre and post concrete pouring? What does he examine? What tests should an engineer preform before foundations are poured. Should the engineer get the pyrite and foundations certificates at these times from the builder? Would an engineer be able to spot that their were no foundations under an extension that was being knocked and rebuilt?

Also, if building over a drain - Council drain running through back gardens - what should tests should the engineer take - how does he ensure that the drain is built over correctly?

Pre concrete pour
Ground conditions
Vegetation
Depth of cutting
Condition of soil
Reinforcement placement
Concrete designed strength
Delivery receipt for the concrete which shows that the delivered concrete was to the designed strength.

You are misled with regards to pyrite. Pryrite forms in the fill material that gets placed under the floor slab. It has nothing to do with foundations. This will Ben dealt with by getting the fill material in compliance with SR21 Annex’s E at that stage.

If your knocking and rebuilding an extension, it should be apparent if there is or is not any foundation.

If there is a council drain, then you cannot build over or without 5m of it. It will contain a wayleave and any works near it cannot be done. Are you sure it’s a council drain and not a private drain?

Hannaho

Hi! Kcerie, thanks for your reply. Sorry, meant to say that the drain is a private drain running behind my house, which is an ex Council House - what are the requirements to build safely over this drain. How do I know it was built over in accordance with Building Regulations. The engineer refused to give us anything certifying it was built over in accordance with building regulations.

Thanks re info on concrete for foundations - the supervising engineer did not get this receipt from the builder either. Re the foundations, we were charged 20k for new foundations, but they built over the old ones, though telling us there were no foundations under the original extension which was knocked. So, basically, you are saying that if they knocked the original extension, they would have known there were foundations under it?

The engineer would only give us certification for parts A and C. He never mentioned the other parts of the building regulations and certification for these, so now we are just finding out what he should have certified.

Thanks for your help. Really appreciate it!

RORY O CONNOR

Batch time of the concrete -check the delivery docket. If the batch time is more than two hours before time on site/pour it may have already started to go off and should not be used. Check the batching docket to ensure the right spec of concrete is in the truck and also check you are getting the correct load volume. If you have ordered 6 cubic meters the docket should say 6 cubic meters.

Check the slump-make sure the builder has not added water to the concrete to make it more workable. Workable concrete should slump at 100/120mm. If it has the consistency of soup water has probably been added. In heavy rainfall, rain can get into the bottle adding water to the mix!

In this heat cover the pour with polythene to prevent premature evaporation of the water in the concrete-think about pouring at the end of the day when the sun is not shining directly onto the site.

Make sure the foundations are deep enough (and wide enough) to the good ground with no soft spots, water, loose earth. Make sure any mesh is not simply lying on the bottom of the trench but elevated and supported by bricks/stones so the concrete actually flows around it.

Don't let the block layers build for two or three days to allow some of the early strength of the concrete to develop. Day old concrete is still green and not strong even if it is hard.

Calahonda52

Op: what exactly did the contract with the "supervising engineer" specify

Hannaho

Thanks for replying. The contract with the engineer said periodic site visits - there were 11 visits. There was supposed to be 5 - but he also made a mistake on planning which costs us more money, and more visits, and meant our house should have come under BCAR but didn't. It was a house renovation and a new extensions - 10.6k fee for 130k renovation. Apparently he used the periodic visits to get out of any responsibility. He said he would only certify A and C of building regs, we didn't know it had to be A to M. However, he signed himself, the supervising engineer on the building contract - it was a builder from his panel. He referred to himself in numerous emails as the 'supervising engineer' and stated that he was also the project manager and designer, so all decisions and costings had to go through him.

We took him to his engineering body, he was recommended for suspension for a year, but appealed it - we're waiting the result of this. His engineering body said he didn't give us the right contract, and it was far too basic.

After two years, having paid for all the documents, we still haven't got certification, we had to have remedial work of 75k done. He eventually 2 years later gave his engineering body his implementation plan - he said when he visited the house when roof structures in attic conversion and kitchen extension were completed, and took photos, that he could find not issues. When the new Chartered Engineer took on the remedial project, he discovered that the kitchen roof design had not been followed at all, and all the timbers were all undersized, and the attic conversion timbers were under stress and needed further support. These were just two of many problems!!

If you, of any others here know exactly what he should have ensured was done, I would be grateful. I am particularly interested to know what type of tests he should have done to build over a drain - a private drain at the back of our house - and what he should have done to ensure it was done correctly. I would be really grateful for this information.

Gumbo

Hannaho wrote: »

Thanks for replying. The contract with the engineer said periodic site visits - there were 11 visits. There was supposed to be 5 - but he also made a mistake on planning which costs us more money, and more visits, and meant our house should have come under BCAR but didn't. It was a house renovation and a new extensions - 10.6k fee for 130k renovation. Apparently he used the periodic visits to get out of any responsibility. He said he would only certify A and C of building regs, we didn't know it had to be A to M. However, he signed himself, the supervising engineer on the building contract - it was a builder from his panel. He referred to himself in numerous emails as the 'supervising engineer' and stated that he was also the project manager and designer, so all decisions and costings had to go through him.

We took him to his engineering body, he was recommended for suspension for a year, but appealed it - we're waiting the result of this. His engineering body said he didn't give us the right contract, and it was far too basic.

After two years, having paid for all the documents, we still haven't got certification, we had to have remedial work of 75k done. He eventually 2 years later gave his engineering body his implementation plan - he said when he visited the house when roof structures in attic conversion and kitchen extension were completed, and took photos, that he could find not issues. When the new Chartered Engineer took on the remedial project, he discovered that the kitchen roof design had not been followed at all, and all the timbers were all undersized, and the attic conversion timbers were under stress and needed further support. These were just two of many problems!!

If you, of any others here know exactly what he should have ensured was done, I would be grateful. I am particularly interested to know what type of tests he should have done to build over a drain - a private drain at the back of our house - and what he should have done to ensure it was done correctly. I would be really grateful for this information.

Because you’ve gone legal here, I don’t think many posters will give you much advice.
If you are building a case of what he should have done, then best to engage a chartered engineer to prepare a document that can be stood over and used as official proof/evidence.

It does sound like you were shafted here unfortunately.