Leaning extension wall

[k77]

Hello - we are having a new 2 storey extension built at the moment. The new side wall of the extension is not in line, vertically, with the existing walls of the house.
As there is scaffolding there at the moment it is difficult to see completely from the ground to the top of the first floor but from where i can see, I think the wall is straight from the ground up to the beginning of the first floor but where the first floor rendered section from the top of the ground floor up is, the wall is not straight and tapers in as it goes up.
I have been up there today with a long spirit level. The corners of the wall, ( 4.5metres in length ) seem to be level, but as I measured towards the middle it is out of line, as far as I can tell - not good with heights on wobbly scaffold - by about an inch, and maybe more if I could measure the full height.
I am going to do a plumb line tomorrow, but I know it is wrong and not straight by just looking at it, as much as I wish it wasn't!
My builders are saying it is a trick of the light, or shadows etc, but I know it is not. We are having our structural engineer visit on Tues, but just wanted any opinions on what would cause it? And what would need to be done to rectify it? Thanks.

 

[freddiemercurystwin]

A plumb line cannot be argued with. I doubt very much it will be structurally unsound, if you report back tomorrow with the actual offset someone with access to the BS will be able to say whether it is within allowed limits or not. Only fix is re-building.

 

[Nige F]

what would cause it - the wind blowing the brickies line in the middle / not using the long level enough as the brickwork rises - Having said that . It`s how whole houses went up in the 70`s I`m not going to make assumptions on the builders competence , not enough info .

 

[^woody^]

I'm confused.

Do you mean out of line, out of plumb out of square, twisting or just bowing?

 

[ChapiTheBricky]

when you say the corners are "level" i take it you mean plumb (vertical) if this is the case, i think you mean it is bowed in the middle, when you say a long spirit level what length are you talking about? 1 inch on an eight foot level isn't ideal but not something you would notice from the ground, wheras 1 inch on a two or three foot level is pretty shoddy.

 

[k77]

Hi - thanks for your replies. Visually it still looks out of line to me, but I have been up there with a plumb line and it appears pretty straight. putting the 6ft spirit level on it, there are places where it is only touching at one end - out by about an inch, but then moving it around a bit it seems to be level at other places. I had our structural engineer here yesterday - just to look. he thinks we should wait until the scaffolding is down, as it might be distorting things, but thinks there might be a taper in at the top. I feel a bit more reassured now and don't think it is a significant problem. I'm hoping a well placed drainpipe will sort it out in the end. Thanks for your input. K

 

[wavetrain]

he thinks we should wait until the scaffolding is down, as it might be distorting things, but thinks there might be a taper in at the top.

Your SE thinks scafolding is distorting a brick wall? And hence it will undistort when removed? And you believe that? Ye Gods!

 

[freddiemercurystwin]

I think the SE means that as the scaff is still up its difficult to assess whether the walls on the pee or not as it can't be viewed on its own (ie distorting the eye's view of it) and there's no space to drop a plum.

 

[wavetrain]

An SE who doesn't have a pocket laser to point up/along the wall to use as straight line reference? Ye Gods!

 

[freddiemercurystwin]

Prey tell, how will having a Disto tell if the wall is plum? You stand at the top (or the bottom or anywhere for that matter) and stick your Disto on the wall and you get a spot on the ground somewhere. How can you tell from this that the wall is plum or not? Without measuring the distance the laser dot is offset from the wall at various heights and at the same time somehow holding the Disto completely 100% vertical? Besides when did it become mandatory for SE's to carry Distos? I await your next bright idea and watch that hole you're digging getting a little deeper.

 

[^woody^]

I feel a bit more reassured now and don't think it is a significant problem. K

If builders can't even build a wall correctly, and if it really is out of range by 25mm in 1800mm, then it should sound some alarm bells in terms of what other basic building are they getting so wrong?

Movement and flexing won't become apparent for a while, during which time your builders are either long gone or "Sorry, it's out of guarantee gov"

And if your supposedly professional SE can see a bowing, twisted, tapering wall with scaffold in front, then perhaps his Labrador could do a better job.

 

[wavetrain]

FMT you are becoming far too agitated for your own good, remember, its only a forum.

As 'woody' indicates, it is child's play to check if a walls are plum, there will aways be some clearance between scafolding and wall to allow trueness checks to be made, otherewise it would not have been possible to build the wall in the first place.

 

[freddiemercurystwin]

I'm still waiting to learn how you'd check a walls trueness with a Disto. The question was is it acceptable not how could they build it out of plumb?

 

[noseall]

If the existing building is out of plumb and the new building is perfectly plumb and the two are joined along the same plane/elevation then this wall will end up 'in twist'.

You would not say build the new wall out of plumb to match the old.

This will also have a a visual effect along the soffit line insofar as it will appear to either widen or narrow along its length, depending whether the wall leans in or out. The soffit detail is not so much of a problem as you have cutting tolerances on the rafter ends.

Putting a level up a wall that is in twist will start reading out of plumb the further you are from the true corner and at its worst the nearer you get to the wonky one.

Hope none of this makes sense.

 

[theoldun]

The recognised tolerances for masonry are 8mm maximum out of plumb for walls up to 5m in height, limited to 8mm in a storey height of 2.5m. Maximum 12mm out of plumb for walls over 5m in height, limited to 8mm on a 2.5m storey height
Two ways to check. Either a 2.5m plumb board, with a plumb bob hole and centre line or a 2.5m aluminium rule with a decent level, with a full bubble and calibrated before use..
We agree with Freddy and the SE, it is not possible to visually tell whether a wall is plumb whist scaffold standards are in place. If you try to visually line in a wall with a standard, the standard could be bowed or out of plumb, consequently it is a wasted exercise Neither is it possible to visually check whether a wall is not plumb even without a scaffold standing.. You must always drop a plumb board or rule down. This should be possible even with standing scaffold.
We note that wavetrain is on his normal posting crusade again and as usual, p*ssing in the wind, how ever it would appear that this time round he has called upon the assistance of the Gods. Possibly he has out grown Tommy Walsh and Cowboy Builders.
Wavetrain, as we have never seen a so called pocket plumb laser that every responsible engineer will have in their pocket, we still use the old fashioned way, line it up against a tree, level it up against a cloud
oldun