Advice needed - crack in internal brick wall

[Perry Gunn]

We're replastering our lounge and having removed the old cracked & blown plaster, we've found a fair sided crack running diagonally in the interior brick wall between the lounge and the old kitchen.

The crack starts at the top corner where the wall joins the inner skin of the exterior wall and extends downward at approx 45 degrees then meanders a bit. There are no major visible cracks on the outer skin of the exterior wall, although one or two bricks have cracks through them but not in any sort of 'connected' way. The exterior extension walls (see below) have no visible cracks at all.

The house was built in the 1930's and the lounge has an extension, put in about 15 years ago by the previous owners, with the opening going through the exterior wall - RSJ put in above the window and the wall below the window removed. There is approx 70cm between the inner wall/outer wall corner and the opening.

We've got a builder coming round this afternoon to have a look at the crack, but I'm pretty worried about this and I'm hoping that someone can provide some reassuring words of wisdom & tell me it's common and not going to cost a fortune to put right.

Perry

[The Natural Philosopher]

Its probably some sort of setlement in the foundations. Up till quite recently foundations had no requirements to be bomb proof and were quite shallow.

You probably have something like a tree growing nearby that has shrunk the soil a bit and caused that part to drift downwards a little.

The 100% solution is to redo the foundations and underpin. About £100 a meter.

But ist seldom necessary to go to those lengths.

Check any 15 year old trees, and lop or remove...and then just patch up the crack.

[bigcat]

You didnt tell us how big it is, but if its under 2" wide, a common approach is to remortar the crack to bond it all back together, and see what happens over time. In most cases nothing more will ever need doing. However if the crack then opens up again, it means the wall's moving and struc expertise would then be needed.

BTW with very soft bricks, I'd use lime mortar or 1:1:6, not stronger cement mixes.

Disclaimer: its your house, your life, and your responsibility to read up and decide what to do, not mine.

Claimer: builders have an obvious interest in making it as complex and expensive a job as possible.

NT

[Richard Faulkner]

In message , Perry Gunn writes

The most sensible thing to do is to pay a Structural Engineer for an inspection and opinion. This will put your mind at rest, and make sure you dont fall for a builders con, (or lack of knowledge).

In the meantime, I wouldnt worry - many houses have cracks which appeared a long time ago and are going no further. If there is no matching crack on the outside, and the inside matching crack, (if there was one), wasnt getting bigger, it is unlikely that anything is ongoing.

BUT DONT TAKE THE WORD OF A BUILDER!!!

[Perry Gunn]

On Mon, 13 Jun 2005 10:45:47 GMT, Perry Gunn waxed lyrical about:

Things appear to be worse than I thought - after my earlier post we decided to remove more plaster and expose around the end of the RSJ to give the builder more to see/work with and we've found that there's no steel there!

The outer skin of the external wall has a concrete lintel and the inner skin has a couple of 5x2 timbers stood on end! Just had a rush trip to the hire shop and now got acrows supporting the opening and the ceilings on either side just to be safe.

How the *%$^ did that get through building regs - and it must have because when we brought the house 2 years ago our solicitor checked that all the documentation for the 2 extensions was correct & signed off.

We've phoned the council and have got the building inspector coming tomorrow to tell us what size RSJ to put in and decide if we're going to need to rebuild the piers with engineering bricks.

So much for a (relatively) simple 'off-with-the-old, on-with-the-new' replastering of the lounge.

Perry

[Dave Plowman (News)]

I've got a Victorian house with a bay only on the ground floor. The 9" solid brick wall above that is supported by a timber lintel. It's survived over 100 years. ;-)

[John Rumm]

And? ;-)

You might be worrying too much. As Dave said, most victorian properties will be built using timber for lintels. On older properties they also often build a slight arch in the brickwork above the lintels (but fill in the space under the arch so you never see it unless you hack the plaster off).

How much wall is there being supported on the timber?

By someone doing the calculations to show that it is adequately supported perhaps?

[Perry Gunn]

On Mon, 13 Jun 2005 15:19:19 +0100, "Dave Plowman (News)" waxed lyrical about:

Thanks for the reassurance - but they knew how to use timber then! This isn't even a solid piece, it's two 5" x 2" lengths, on edge, & they don't even appear to be bolted together.

Having spoken to the builder it doesn't look like it's too much of a nightmare to put right - although final cost will depend on what the buildings inspector tells us we've got to do - and the builder is an old friend of our future son-in-law so he's a known quantity.

I don't really fancy this as a diy job - not when a slipup could cause this much damage! Much as I hate paying builders, I'll only get him to do what the inspector tells us we have to do.

[Perry Gunn]

On Mon, 13 Jun 2005 15:46:31 +0100, John Rumm waxed lyrical about:

The opening is about 8ft. It's a two-story house and the opening was originally a ground floor window (now free space) and the wood is bridging the inner of the cavity wall skins.

Point taken! Although it doesn't appear to be adequate any more given the subsequent movement of the wall and cracking that has occurred.

[Simon]

I would have thought that if the wooden lintel had not been strong enough the cracks would have been upstairs above the lintel not downstairs.

Simon

[David Hearn]

Are you aware whether the original window was 8ft wide, or was the opening widened?

D

[bigcat]

sounds good.

?

Wood lintels are standard on Victorian houses, and work fine, as long as they dont rot.

A lot of old houses of course have no lintels at all, which is a bit naughty, but they do normally stay up.

this isnt making much sense. Lay off the caffeine. :)

you dont have to do anything.

You really need to calm down then look at all this again. Meanwhile I'd be returning the props, if it were my place.

I'm not tryint to tell you what to do, the decisions are all yours, and you'll live with the results.

NT

[Rob Morley]

Maybe it's not required.

A couple of 5x2 next to each other is pretty much as good as a single

5x4 - they will be more prone to bowing sideways if not bolted together, but the vertical stiffness will be the same.

The problem sounds like settling in the foundations rather than weakness in the lintel, although I'm not sure that I've understood your description of the situation.

[Tony Bryer]

Statistically better (2no 5x2 are 1.14 as stiff as a single 5x4 when calculating to BS5268) because it is highly unlikely that any knots or other weaknesses in one piece will also be in the other piece at that point, whilst with a single piece a knot may carry through.

[Rob Morley]

I hadn't considered that, but of course it makes perfect sense.

[John Rumm]

So is the opening the same size as before - just with the window removed? If so I would expect any support above to still be adequate.

Well if you were getting cracks forming above the lintel then yes.

You have neglected to mention the type of soil in your area, but the type of crack you describe is typical on clay soils and can be caused by changes in the water table, or commonly by close proximity of tree roots.

[Perry Gunn]

Thanks to everyone for the advice & suggestions - even the one about laying off the caffeine. :-)

My 'Oh Sh*t!' reaction is pretty typical for me - find something unexpected and think the worst, then investigate/ask questions and find out it's not as bad as all that! And a good night's sleep always seems to put things in perspective

We're currently awaiting the visit from the inspector and we'll just have to see what he says about replacing the wood - if we have to do it, we have to do it! Could do without the extra expense though!

Thanks again to all who responded.

Perry

[bigcat]

Can we all quote you for some work? I'm sure you need new piers to support your new steelwork, after all you cant rest steel on nothing.

Plus I'd have to put new foundations in for those piers of course... thats life.

My mate ere says you need to rewire that socket cos its so dangerous. In fact it all is, have to rip the lot out and start again. You've got to do it!!!

Sheesh, who put the window in like that? That could fall down at any moment! You'll need new double glazing, in lovely self yellowing self cracking plastic, plus a full set of new lintels, those old concrete ones are no good.

Oh my, who put your boiler in?? Good lord, you must get that seen to before winter, dont want any accidents there.

Perry.... relax :) You've got more support there than millions of houses in the UK, and theyre not falling down. Its quite common to find Victorian wood lintels that are rotten, there are 100s of 1000s of houses without any lintels, and so on.

NT

[bigcat]

Can we all quote you for some work? I'm sure you need new piers to support your new steelwork, after all you cant rest steel on nothing.

Plus I'd have to put new foundations in for those piers of course... thats life.

My mate ere says you need to rewire that socket cos its so dangerous. In fact it all is, have to rip the lot out and start again. You've got to do it!!!

Sheesh, who put the window in like that? That could fall down at any moment! You'll need new double glazing, in lovely self yellowing self cracking plastic, plus a full set of new lintels, those old concrete ones are no good.

Oh my, who put your boiler in?? Good lord, you must get that seen to before winter, dont want any accidents there.

Perry.... relax :) You've got more support there than millions of houses in the UK, and theyre not falling down. Its quite common to find Victorian wood lintels that are rotten, there are 100s of 1000s of houses without any lintels, and so on.

Klaxon!

NT

[Richard Faulkner]

In message , Perry Gunn writes

I would still recommend a Structural Engineers Inspection and Report