Is my house about to fall down?

[Adsibob]

I’m knocking down the full width of the rear ground floor of my house. Have a good structural engineer who has done a detailed design which impressed the architect. But he didn’t specify how to knock down the rear wall, which I guess is normal. No need to teach an experienced builder how to suck eggs. At least that’s what I saw until I saw this.

This is a view from upstairs and shows how they have temporary supports coming from the ground up through the first floor and supporting each side of six short RSJs that in turn supports the rear upstairs wall of the house. It is not how I was expecting them to do it, but what do I know. What do you think? Presumably they will add a seventh pair of supports for a seventh RSJ in between the two on the left and middle of the photo so the supports are all more or less equidistant. 
Thoughts?

[Russell griffiths]

Looks perfect to me, exactly how I would do it. 

[Gus Potter]

Unfortunately all may be not well from the one photo posted.

 

At first floor level (the photo?) there is no bracing / lateral restraint to prevent rotation of the needles (RSJs) on plan. What is going on at the ground floor. The needles under the windows are only holding up a few course, the props may lift the masonry here. A lot of load could be coming down that masonry pier between the two windows so all the roof load (depending on span direction) could be on the props here and they could easily be very overloaded, buckle and collapse. The tops of the needles have not been dry packed / packed by the looks of things. When you take the wall down you may get some local crushing of the brick.. movement. Also, the props holding up the pier may not be able to carry the load, especially if they are not braced and footed properly at ground floor level.

 

I would strongly recommend that before you progress with taking down the wall you get an SE to have a look at this.

 

 

[Mr Punter]

One or two pins missing.  Make sure the acrows are tied together with scaff poles.  Make sure they all are vertical and have a proper footing.

[Adsibob]

Just to clarify, I don’t know whether or not they have finished the preparatory work. But based on the helpful comments here, I definitely need to check first thing tomorrow morning!

[Adsibob]

3 minutes ago, Mr Punter said:

have a proper footing

What constitutes proper footing?

[Mr Punter]

1 minute ago, Adsibob said:

What constitutes proper footing?

 

Some nice, solid ground.  Like if you dropped a sledgehammer where the base was going from a height of a metre, after 50 goes it would not be sinking down.

[PeterW]

You’re paying the builder to do his job ..? Let him do his job. Assume he’s insured and let him crack on and finish the prep. 

[Adsibob]

Yea, he’s insured and experienced. I just have OCD.

[Russdl]

@Adsibob WAY better to ask than wish you’d asked. 

[markc]

You can see the support works are not yet finished (another hole started), the UB`s are not new and pretty much an ideal length - They have done this before

Edited January 28, 2021 by markc

[ProDave]

Check VERY carefully that the builder IS insured for this.  Does your own building insurance know what work is being done and what have they said?

[Adsibob]

5 hours ago, ProDave said:

Check VERY carefully that the builder IS insured for this.  Does your own building insurance know what work is being done and what have they said?

Yes, all good. I made it a condition precedent of our contract that he provide me with his insurance policies. He did and I checked them and they are all in good order. My buildings insurer is also aware and has charged me an additional (and extortionate, in my view) premium for the additional cover. 

 

Anyway, I spoke to the builder this morning and they aren't ready to do the actual demolition yet. Still have some further supports to erect.  

[joe90]

11 minutes ago, Adsibob said:

. My buildings insurer is also aware and has charged me an additional (and extortionate, in my view) premium for the additional cover. 

Why the need to have two sets of insurance, just more money printing IMO.

[Adsibob]

4 minutes ago, joe90 said:

Why the need to have two sets of insurance, just more money printing IMO.

Different insureds. E.g. all mortgages require the mortgagor (i.e. the borrower) to insure the mortgaged property adequately. I would be in breach of my mortgage contract if I didn't notify my insurer that I was having building work done and amend the policy accordingly.

That is very different to the situation when I need to make sure the builder is insured; i.e. say he's negligent - there is not much point suing him (actually it, as the contractor is a private limited company) unless it is adequately insured. Otherwise I'm relying on the asset position of the limited company the builder is operating through, and most small to medium builders don't have a significant asset position.

Also, I'm fairly sure that my buildings policy won't cover the situation where one of the builder's employees has an accident during the building work. Whereas one of the builder's two policies does cover that.