Bowing house wall - tie rods?

[Grunff]

Background - our house was built in the 30s, has a square footprint around 8x8m, and has no foundations to speak of. It's made of stone + lime mortar, and the walls are between 50 and

60cm thick.

When we bought it 2 years ago, we noticed that the back wall had at some point in the past bowed, so that while it's still attached to the outer walls, it's come away from the internal partition walls, causing a lot of cracks between the end wall and the partitions, and the end wall and the ground floor ceilings.

We filled these cracks so that we may study future movement. Two years on, the wall seems to have shifted by another mm or so.

The wall isn't sinking - there are no cracks at floor level downstairs. The cracks appear about 1m above floor level, and increase in size as you go upwards.

Similarly, the wall is still firmly attached to the two exterior side walls. So it's only moving outwards in the middle. It's bowing.

I know the traditional fix for this is to tie the two opposing walls together with steel tie rods, and spread the load on the outside of the walls using steel plates.

I am considering doing this to our house. The obvious place to run the steel rods is between the floor and ceiling. This would be fine, since they'd run parallel to the joists.

Has anyone done this before, and do you have any advice to offer? Is there anywhere when I could read up on this? Basic stuff - like how big the rods should be, how big the plates should be, how far apart, how many (two seems very common), that kind of thing.

TIA

[BigWallop]

Just reading the first part of your post and I would advise you to call in an engineer to take a look. If this movement is continuois, then something needs to be done to stop it. You say that it is opening further and further every year, so it will eventually get the point of no return and may collapse.

If the movement had taken years to open to a couple of millimeters, then it is not as urgent, but as you say your problem is happening over a shorter period of time, then it might just be safer to get it looked at.

Good luck with.

PS. And just another point. Ask your insurance company what they think. (this came from the little woman sitting behind me, who seems to be up on that sort of thing)

[Grunff]

Well, yes, that's the obvious answer, but I'm looking for more info at this stage.

TBH, I'm not terribly worried about the wall collapsing, because [a] It's very unlikely to do so, given that it's stood this long, and is supported by a great big stone porch on the outside, and [b] Even if it did, it really wouldn't be the end of the world, and would give us a good reason to rebuild the house.

It's been on the move since at least the 60s, because we found some 1960s newspapers stuffed into one of the bigger cracks.

Thanks. No google link? ;-)

[John Laird]

[a] But you say it is still moving... What gives you confidence that the movement will stop before it eventually collapses ? I don't think "it's stood this long" is a particularly sound reason, engineering-wise ! [b] Do you think this wall is non-structural ? What's to say your house won't come down with it.

I think you ought to get a structural engineer to take a look (was anyone other than a surveyor involved when you bought the place). You could start off the whole process with a call to your insurers, but be warned that after a claim you may be unable to ever change companies.

I had a bulging back wall re-tied as part of the mortgage conditions on my house - the outer leaf had come adrift from the inner (structural) wall.

[The Natural Philosopher]

I think you ought to get a structural engineer to take a look (was anyone

Structural engineer is MANDATORY. NOT expensive either usually. DO WHAT THEY SAY and then you can sue them - or your insurance company can, when the house falls down.

Its really not expensive to put a tie rod through and tighten up the bolts.

Just make sure its as specified by certified engineers with liability insurance.

Then you are covered against mistakes.

[Grunff]

No, the wall most certainly *is* structural, and the house would most definitely come down with it. But that wouldn't be the end of the world. That's what I'm saying.

Hmm..maybe. No, we didn't have a structural survey done (we were fully aware of the problem).

[Grunff]

What qualifications should one look for in a structural engineer? Are all structural engineers listed in the yellow pages equal?

[Darren Griffin]

It may well be the end of your world if you are in the house when it comes down.

[Grunff]

I think it has a fair way to move before that happens, and would be pretty obvious that something bad is about to happen. Houses very rarely spontaneously self destruct without warning.

[James Salisbury]

Try a Chartered Civil or Structrual engineer, a decent engineer needs C Eng after her or his name.

[PoP]

As others have said, and perhaps to lend weight as if we were voting on the next step, I'd consult someone who knows what they are talking about. And your insurance company should be part of the deal.

It is possible that your insurance company has a get-out clause buried in the fine print, in so far that at the time you purchased the property there was a problem. That should have been noted by the surveyor who inspected prior to purchase. Depending on his description may be whether the insurance company feel they are liable (and like all insurance companies their starting gambit will tend to be "not us, guv!").

Remember that the Titanic didn't sink instantly after coming into contact with a block of frozen water.

PoP

[BigWallop]

Please say your not sure. All it can take is some ground movement or a heavy lorry passing the building, to take any precarious structure over the edge. Do you know that the joist are still properly seated on their retainers ? Have the joists moved out of their original position and are now sitting on crumbling mortar.

A low flying jet from RAF Leuchars, brought down a cottage in the wilds of the Ayrshire country side. So please, if you can see that the movement is continuing at a pretty even rate over short periods of time, then have it looked at properly. We'd all miss you.

[Grunff]

I don't think so. First off, the wall isn't sinking - there's no movement at ground level. It's bulging out, greatest bulge at the centre of the wall. Second, I don't believe the porch walls are tied in to the bulging wall - it appears to have just been built there, in contact with but not attached to the wall.

[John Rumm]

Are you sure its not the porch that is sinking and pulling the wall with it?

[Grunff]

Greatest deflection is aout 30mm, over 70 years. The joists are still nicely in their holes, that was one of the first things I checked.

I'm touched...

I will be doing something about it - don't worry. Just getting the group's thoughts first. I like to understand things. I'm trying to understand what possible solutions may exist. I like to have this information before calling in someone who may or may not know what they're talking about.

[Dave Baker]

Ummm, run, run very fast. Run now.

Seriously, it must have foundations or it wouldn't stil be up.

It's

I remember Fred Dibnah doing this to his house in his tv program. I think you'll find the rods and plates are pretty much of a std size unless it's a castle you're trying to shore up. The plates are about 1 foot in diameter (or they can be crosses) and the rods are about an inch. Two in 8m sounds plenty. A

1 inch mild steel bar will withstand over 20 tons and there'll be nothing like that sort of force pulling at your walls or they'd be down by now.

I read through the thread before posting and the bit about the front porch is worrying. If the walls are bowing but not sinking and the porch is still attached to the walls then the porch must be sinking or something else would have had to crack. I think the porch could well be your problem.

Dave Baker - Puma Race Engines

I'm not at all sure why women like men. We're argumentative, childish, unsociable and extremely unappealing naked. I'm quite grateful they do though.

[Grunff]

Ok, it has some very shallow stone foundations. No deeper than a foot.

I know - it's puzzled me too. I concluded that the bowing wall must be pushing the porch out with it. I think if the porch was going to sink it would just detatch from the house. I could be wrong.

[Richard Faulkner]

In article , Grunff writes

What are you waiting for - are you skint? a cheapskate? stupid? naeive? .........

Get a structural engineer in fast. It will cost around £175 to £400 or so, for a visual inspection, initial prognosis and advice for further inspection and/or cure.

The longer you leave it, the more chance of having to rebuild the wall than using simple metal strapping.

I would get the engineer 1st - before involving your insurance co.. You may not need, or want, to bother with insurance.

This is not Do It Yourself - you need the correct paperwork to satisfy a surveyor when you sell.

[Grunff]

None of the above. I'm ... laid back.

What is the correct paperwork? This is exactly why I posted my question.

[Owain]

"James Salisbury" wrote | > What qualifications should one look for in a structural | > engineer? Are all structural engineers listed in the yellow | > pages equal? | Try a Chartered Civil or Structrual engineer, a decent engineer needs | C Eng after her or his name.

You want a Structural Engineer who will be MIStructE (Member of the Institute of Structural Engineers -

but I don't think they have an online member listing[1]) and CEng as well.

Owain

[1] They do have but it's a paid-for listing rather than a comprehensive register of members. You could try a local reference library for the IStructE Sessional Yearbook and Directory of Members