Problem with structural wall changes & new RSJs

[bigal993]

Guyz Im after some advice,
I am refurbishing a detached house which was built in 1960, if you can imagine looking from a plan view above, the house had a cross section formation that split up the lounge - diner - kitchen - hallway.

As you walked in the house the front door was on the right the wall to your left was the main bearing wall, with two doorways in it only with a 6inch brick pillar between them and the wall ran the full length of the house, the plan was to brick up the two door ways which went into the lounge and dining room, then take down the wall which split the lounge diner to make the lounge bigger and replace with a stud wall RSJ to be fitted where the original wall was, the doorway into the kitchen would stay, but the wall which continued thru the kitchen would come down and a new rsj would go in, there would be a new solid block wall built to support the two RSJs.

I found a SE to do the calcs for the job and, he recommend a builder they visited site and the builder asked about wether new concrete pillars needed to go in under the new block wall for support and the engineer said no, it will be fine, all went reasonably smoothly, job completed building control signed it off two weeks ago,

Until Friday I was preparing to take up the quarry tiles in the kitchen which has now been opened up to a kitchen /diner, and where the old doorway was and where the new wall is to support the RSJ, I found found to my horror, that the floor underneath the quarry tiles seems to be a 50mm bed of mortar, our new wall is sitting on this thin floor, area, and this is a main load bearing wall.

I have paid the builder his chq went thru on friday, I feel a bit sorry for the builder, as he only went by what his structural engineer, recommended, the problem I have is the house has just been fully plastered,

I think a section of the floor needs to come up and we will have to put concrete under the new wall, but i cant see us being able to do it without disturbing works completed.
what do you think, should it have been picked up or at least recommended for inspection by The SE to ensure the floor could cope ?

Sorry about the long post Guyz just after some opinions

 

[noseall]

Why do you feel sorry for the builder? He has done as requested, has been paid and is not liable.

The structural engineer should have insisted on a pilot hole and building control should have inspected it, long before the builder got there or prior to any of the building works starting. And you should have either dug it or picked up the tab.

I am very surprised that no one, including the builder never gave it a thought.

Everyone involved has been unprofessional.

I would say that your liability lies with building control and the structural engineer - especially the structural engineer as they are the ones who must be obeyed.

 

[bigal993]

Why do you feel sorry for the builder? He has done as requested, has been paid and is not liable.

The structural engineer should have insisted on a pilot hole and building control should have inspected it, long before the builder got there or prior to any of the building works starting. And you should have either dug it or picked up the tab.

I am very surprised that no one, including the builder never gave it a thought.

Everyone involved has been unprofessional.

I would say that your liability lies with building control and the structural engineer - especially the structural engineer as they are the ones who must be obeyed.

Why should I have dug it out, thats why I employed people to do it !! Those People who are supposed to know what they are doing !

if we wanted a botch job we could have attempted it ourselves but we paid good money for the SE & the SE recommend builder to do it, as I do not touch structural works, we told them what we wanted to do, and we paid them what they asked us to pay for the specified works,

I feel sorry for the builder because he was recommended by the SE and attended site with the SE on the initial visit, so he is involved, he has very kindly offered to help me sort it out

 

[noseall]

Don't take offence.

The customer the option to dig a pilot hole (or not) as this is usually a pre-cursor to the main job and is often done some time prior to the actual works and can determine the outcome i.e. do i demolish or not etc.

Sometimes the results can determine whether a job is actually feasible and is often required long before quotes and builders are brought in.

However I can understand your frustration. Your liability is still with the S.E.

Are you positive there was no conversation about the wall actually being load bearing or needing proof etc? I find this story bizarre.

 

[bigal993]

No offence taken mate, during there initial visit to view the job and price it up, I did hear the builder ask the SE about putting a pad in on the other side of the room where one of the RSJs was going to sit on the inner skin of the house, but the SE said no it will be fine.

Also Building control have been out and said the structural part of the works has passed, we still have a window with fire opener to be fitted so they havent sent the final completion cert yet, but i do have confirmation that the structural element has passed

I did notice that the dining room floor has sunk about 15 mm against the outer wall and mentioned that to the SE in an email but that wasnt in connection with this job, just a general enquiriy as it was where we were going to put a patio door, the alarm bells rung on Thursday during a conversation with my flooring guy, who when I told him about removing the quarry tiles, he asked how old the house was I told him 1960 and he said just check what the quarrys are laid on as they used to lay them on 50mm bed and ash underneath, thats the only reason i checked the floor,

so bloody frustrating mate,as the house has just been plastered top to bottom

 

[amwc]

This is an interesting post.
But am I missing something? what made the SE assume that a supporting wall built randomly would be ok without foundations?
I take it this new wall has not been built in an area where there once was a wall?
and are you also saying that 50mm underneath your kitchen floor is soil?

Interesting!

 

[limerockconstruction]

Usually I agree with Noseall on most things, but, as a Builder, I would still do some due diligence on the area before assuming that the Engineer was correct. I think as professionals we owe our customers that responsibility. Not to just plough on regardless, but be diligent about all aspects of our work, especially steel work.

Although it is frustrating when these expensive professionals get it so wrong!

 

[wessex101]

I'm struggling to understand so bear with me.

So you are saying they blocked up the old doorway to support the end of the new RSJ and those blocks have been built directly off the quarry tiled floor?

Under the quarry tiles is 50mm bed of mortar.....sand cement screed maybe?.......then what? Concrete slab? Or maybe the footings of a wall? I would be extremely surprised if this 50mm bed of mortar is directly on soil.

I think you need to do a bit more investigation to establish exactly what is under the new blockwork and then speak to the structural engineer.

In my experience engineers are infuriatingly over cautious massively over designing everything so you would be very unlucky to find the one engineer who took a gamble and got it wrong.

If I have completely misunderstood your post please feel free to ignore my ramblings.

 

[NS215]

Maybe I'm reading it wrong.... But I read it as the new block wall was built upon the old wall that was removed, and on original footing not the floor that was laid on a screed, like I say prob wrong as most others seem to be thinking differently

 

[noseall]

Usually I agree with Noseall on most things, but, as a Builder, I would still do some due diligence on the area before assuming that the Engineer was correct. I think as professionals we owe our customers that responsibility. Not to just plough on regardless, but be diligent about all aspects of our work, especially steel work.

Although it is frustrating when these expensive professionals get it so wrong!

Totally agree.

There is not a cat in hells chance that we would have ploughed on ahead without having conversations with fellow pro's about the validity of the wall foundations.

It seems to me that the S.E. has said to the builder that it is ok and the builder has shrugged his shoulders and carried on. Whilst i do not condone this, it seems that there is a cozy relationship, in this instance, betwixt the builder and the S.E. and the builder has put his trust and the liability onto the judgement call of the S.E.

I think impartiality is missing from this particular scenario and that's very unfortunate. Oh, and the builder is a t wat. But let us also not forget that the S.E. is the more "senior" professional and MUST be obeyed.

 

[amwc]

I agree with Wessex101 theres not an SE I know that would just blindly say stick a load bearing wall on top of quarry tiles and that will be ok. If it is in line with an old wall position there is obviously footing under it?

Is there something missing here?

 

[noseall]

Is there something missing here?

I am wonering the exact same thing.

 

[bigal993]

Gutz
let me update, the wall was built to close of two doorways, there was a 150mm dividing wall between the two doors, we were removing the quarry tiles, in the kitchen because they had blown in places, when we had removed them, I tapped the screed to ensure it was sound, it was as hollow as hell, so i put a 150mm sds drill thru the screed, it went straight thru, the screed into a sandy/ash based material this was at the side of the new block wall, i did another test hole in the hallway at the start of the block wall same thing, straight thru, we did some digging this week, and found two chambers in the floor, they had the remnants of copper pipes in them, which were from the original heating system, i had drilled into two bloody chambers in the floor, just my luck the whole floor too chose from, and i hit two chambers, after digging down the foundation brickwork does carry on thru under the original doorways, but with two inch of sand/cement screed over them, the screed had blown on 50% of the kitchen floor, so sounded hollow in a lot of the surface area, but that been sorted this week, to be fair the builder is a good guy, and said straight away, if theres a problem he would sort it out,
thanks to tony1851, who offered some great advice, and everyone else for there input
Al