Neighbour building an extension

redser7

Thought I'd revisit this as the extension is complete now. Can't fault the neighbours or the builders or indeed the finished job. Looks good to my untrained eye and I've been keeping a close eye on it as it went along. The builders were respectful and tidy at all times as they had to access our garden a few times. The party wall is bang down the middle and the exterior finished very nicely, just waiting to dry and be painted. The neighbour is very happy with the job and says it went like clockwork without any delays.
But one thing came up while chatting to him. They didn't get a cert. I asked about it and he seemed relaxed about it and said that it could be got in the future if it was needed and sure they'd be carried out in a box in 40 years. He said he took lots of photos along the way which he will keep.
But I wonder how that affects us if we want to build against that new party wall in the future. Also, to be honest we were going to approach the builder and ask for a quote to get the same thing done. He's done 3 pretty identical jobs now in our estate (knocking kitchen/diningroom wall and squaring off the L-shaped kitchen). We're sort of tyre-kicking but all the construction going on got us thinking about brining it forward.
It's all new to us but reading around I see that certification is very important. So any comments?
Thanks

BryanF

how can a structural foundation cert be produced retrospectively? Unless the engineer did inspect and just hasn't been asked to produce the physical piece of paper?

redser7

Is that an actual question for me or rhetorical? It's the neighbours build so I honestly don't know. The 'impression' I got from his relaxed attitude is that there will be no certs issued and therefore no inspections were done. I didn't ask straight out was an engineer involved.
I'm in a tricky position in that it's not my build but it affects me. I'm also in a tricky position in that I know nothing about construction and compliance. So please assume you're talking to a dummy and can you tell me what ramifications it could have for me in the future (not just nuclear disaster ramifications) and can certs be obtained retrospectively if needed?
I do appreciate any advice.

BryanF

to build off the party wall in the future it would be best of you had a copy of the cert / structural spec for your shared boundary foundation/wall.

If an engineer wasn't involved at the time/ hasn't inspected the install of foundations/rising wall then I don't see how they can respectively issue a cert.

Ramifications may be minor, a seasoned engineer might just inspect your side of the foundations and design an extension of the wall. but then we don't know what s/he might recommend until you go to extend. What if they say 'I don't know what the construction is, we should build a separate wall'?

redser7

Thanks Bryan. Hopefully his photos are extensive and allow someone to issue a cert (opinion - I'm learning!) in the future. I'll talk to him about it.

BryanF

redser7 wrote: »

Thanks Bryan. Hopefully his photos are extensive and allow someone to issue a cert (opinion - I'm learning!) in the future. I'll talk to him about it.

If your unwilling to chase this cert, at least ask for a copy of all photos pertaining to the party wall - if it were me I'd be looking for a picture of the trench, rebar(steel fixing/cover), poured concrete foundation etc oh and if available a copy of concrete delivery mix ratio. (I'm not a structural engineer btw)

redser7

Thanks again! I'll mention that to him alright and get the copies.

redser7

BryanF wrote: »

If your unwilling to chase this cert, at least ask for a copy of all photos pertaining to the party wall - if it were me I'd be looking for a picture of the trench, rebar(steel fixing/cover), poured concrete foundation etc oh and if available a copy of concrete delivery mix ratio. (I'm not a structural engineer btw)

Your talk of foundations brought something back to me! God.
For the party wall, they didn't dig foundations. The existing party wall which was cavity block, was taken down to the ground. Then (and I use my own words here to describe as best I can) two layers of long precast concrete slabs/bars where laid down and the wall of new blocks (solid on the flat) was constructed on this. Does it sound like something that is done in practice? Perhaps they've just built on top of an existing foundation from the original separating wall and didn't need to dig a new foundation? The had already done at least one other identical job on our road so maybe they knew this was ok?
When it came the front of the extension they did dig out the concrete path, dig out the soil and pour a new foundation. This was a short enough strip about 3 metres long where the french windows went in.
Sounds like a bodge describing it like this but hoping it's ok.

BryanF

BryanF wrote: »

Removing boundary to build extension all sounds quiet reasonable and is imo typically best practice. I would expect that your neighbour's structural Engineer would provide you with a Structrual cert

redser7 wrote: »

Your talk of foundations brought something back to me! God.
For the party wall, they didn't dig foundations. The existing party wall which was cavity block, was taken down to the ground. Then (and I use my own words here to describe as best I can) two layers of long precast concrete slabs/bars where laid down and the wall of new blocks (solid on the flat) was constructed on this. Does it sound like something that is done in practice? Perhaps they've just built on top of an existing foundation from the original separating wall and didn't need to dig a new foundation? The had already done at least one other identical job on our road so maybe they knew this was ok?
When it came the front of the extension they did dig out the concrete path, dig out the soil and pour a new foundation. This was a short enough strip about 3 metres long where the french windows went in.
Sounds like a bodge describing it like this but hoping it's ok.

what depth were these 'slabs' installed at? we cannot comment on specific structural installations (see forum charter). My advice get a structural cert for your neighbour, it's your party wall too. Best of luck with it.

redser7

I understand.
I wasn't around the day they started the new wall and it was a few courses high by the time I got home.
The previous day the old wall was taken down to the ground, level. I think the 'slabs' were simply placed on top of the flat surface. And the wall built on top of that.

Drift

Hi OP.

Did the long "slabs" look a bit like what's shown in the link below:

http://www.tullyleek.co.uk/images/postcard/large/prestressed-concrete-lintols-01.jpg

Bearing in mind that ones in the picture are sitting on their side.

What you describe sounds to me like they placed/left concrete lintels on the existing foundation and then built the new block on flat wall on top of this. I might be way off though!

As mentioned above we're not allowed give structural advice here but I think it would be safe to say that I personally would not consider this to be best practice .... if it's what happened.

redser7

Thanks Drift. Yes these look exactly like what was used. I understand your predicament but I guess I'm trying to unravel backwards what may have been done rather taking advice on a way to go forward with a building.
Hypothetically speaking, on a scale of 1 - 10, 10 being best practise where would you place such a practise?
Cheers

Drift

Hi redser,

Even if I wanted to answer that I couldn't here!!!

But I'd be afraid to anyway - without having seen the wall being built or seen some "designs" for the foundations I could be worrying you unnecessarily or worse reassuring you wrongly!

Do you know you any structural engineers? If you get the pictures from your neighbour you could show them to one and ask for their opinion. It sounds like no engineer was involved from your neighbours side so I think the chances of ever getting a cert are very close to zero!

redser7

Understood Drift. I feel a bit the same away about worrying the neighbour over their lovely new extension. But it needs to discussed, we have a right to build on too.
Thanks again

BryanF

redser7 wrote: »

Thanks Drift. Yes these look exactly like what was used. I understand your predicament but I guess I'm trying to unravel backwards what may have been done rather taking advice on a way to go forward with a building.
Hypothetically speaking, on a scale of 1 - 10, 10 being best practise where would you place such a practise?
Cheers

redser7 wrote: »

Understood Drift. I feel a bit the same away about worrying the neighbour over their lovely new extension. But it needs to discussed, we have a right to build on too.
Thanks again

Redser
What more can we do. You know we can't offer an opinion on the structure. May I ask, what discussion did you have regarding the party wall with your neighbour before works started? Did the suggestions made here get discussed?

If your speaking to the neighbour explain that just because he plans to stay there doesn't mean he should haven't certs showing compliance with building regulations, in the event that something forced the sale or remortgage the lack of cert may become an issue.but from what you've stated above, in relation to your party wall, I'd expect to see an engineers cert

redser7

Construction seems to be more of a minefield than I had thought so apologies if you feel I'm pushing for information. Perhaps my queries might have yielded a response from someone along the lines of 'new foundations MUST be made when upgrading a party wall'. This could be given as sound general advice and not specific to this case which could land someone in hot water. How do I know?
The builder called in one evening and answered any questions I had. Foundations was not one of them and neither were certs. Suffice to say hindsight is 20-20 and things would be different if I could go back.
I'm reckon the neighbour understands perfectly well what the scoop is with certs. Some people are simply not bothered, some are. I would be the latter type.
Thanks again for your time.

BryanF

redser7 wrote: »

Construction seems to be more of a minefield than I had thought so apologies if you feel I'm pushing for information. Perhaps my queries might have yielded a response from someone along the lines of 'new foundations MUST be made when upgrading a party wall'. This could be given as sound general advice and not specific to this case which could land someone in hot water. How do I know?
The builder called in one evening and answered any questions I had. Foundations was not one of them and neither were certs. Suffice to say hindsight is 20-20 and things would be different if I could go back.
I'm reckon the neighbour understands perfectly well what the scoop is with certs. Some people are simply not bothered, some are. I would be the latter type.
Thanks again for your time.

My advice to any client dealing with a party wall extension: either you get a cert and/or you pay for your neighbours choosen engineer to inspect the party wall install