Erm... the walls don't quite meet

[kaz]

Whilst the windows are being tackled, a friend is going around the inside of the property filling small cracks using natural hydraulic lime (hope that's the correct stuff to use). Anyway... he's been chipping off a small amount of plaster surrounding the entire crack before filling. Everything was going ok until he reached a crack running down a corner of a bedoom wall... one tap and a hole revealed itself (the internal wall doesn't quite reach an external wall).

It looks as though the 4" gap between the 2 walls had been stuffed with brown paper and plastered over by the previous decorators (there's quite a big void behind the hole). My question is... what do I do next?

Any advice would be much appreciated.

 

[MdB]

I think that is a "call a structural engineer" type of job. I doubt anybody here will give any other advice as it the sort of thing which a) needs somebody that knows what they are talking about and b) they need to see it in person.

(Oh and you should be using hydrated lime not NHL inside and for most external work. Not that it will matter much and it is a lot better than the C word)

 

[Me!]

Is the gap wider at the top than it is at the bottom? If so, then it could be wall-spread caused by the weight of the roof pushing the walls apart. Is the roof just outside that bit of wall an eaves bit, i.e. with a gutter not a gable end? What are the walls and roof made from please?

 

[Nemesis]

Is this an internal partition wall not reaching an external solid wall?

 

[inwood]

Is this an internal partition wall not reaching an external solid wall?

I agree, looks like lath and lime plaster on the right hand wall. That being the case it may just be a case of taking off old laths and replacing with longer ones. I had an internal lath and plaster wall where the laths were all over the place and in places were about 50mm away from the wall, with others touching.

What's on the other side of the wall, are there any other signs of movement around this joint? Do the floorboards meet the wall, are there signs of cracking along the joint between the ceiling and the wall on the left?

If these are both external walls or there are additional signs of movement then a structural engineer will certainly be the best way to go.

 

[kaz]

Many thanks for the replies… I’m feeling a little anxious about this situation (understatement).

In December last year I had a full building survey. The surveyor noted the ‘crack’ but wouldn’t have known about the hollow space behind it. However, he looked externally to see if there were any visible signs to correspond with the internal crack. The house was restored 8-9 years ago and there doesn’t appear to have been any external movement since then (the pointing has remained intact). I don’t know how significant this is, but at the time of restoration, central heating was introduced (the house had previously relied on open fires for warmth).

It’s hard to assess whether the gap is wider at either the top or bottom because not the whole area is exposed (the plaster has remained intact)… however, the thin baton type things behind the plaster are not all the same length, so making the gap larger in areas.

When you mentioned the weight of the roof, my heart skipped a beat. The surveyor didn’t like the direction of the main beam in the room below the ‘crack’… in fact, the main beam acts as a divide halfway along the ceiling where each side has beams going in opposite directions (see pic). This main beam corresponds with an external ‘S pin’ (not sure what it’s called).

The front of the house is brick and the back is mostly wattle and daub. I’m guessing that in line with old fashioned snobbery, the roof tiles at the front are hand made clay ones and at the back there is a mixture.

As for the gable end and external solid wall… my knowledge is pathetic (but I’m learning). I am posting pictures and have chucked in arrows to indicate where the internal crack is located.

Hopefully you’ll be able to see why I’m confused and unable to answer whether the wall is an external one or not… it may have been at some point in its history, but it looks like the house has been extended, which may explain the change in direction of the beams in the room immediately below. So… if the wall was originally an external one, there's no sign of any bricks.

There has always been a weird gap between the floor and wall... nothing is even. The surveyor removed a floor board in that room and directly underneath were coffin boards (whatever they are :shock.

Here's the section of the house affected... I've inserted a couple of wobbly arrows to show where internal crack is (also you can see why I think there may be an extension here)

External pin and intact pointing (you can see that there has been previous movement because the bricks are pulled in).

The main beam in the room below with arrow pointing up to where crack is in room above. Also note the different direction of beams.

Sorry about the long post, but I am sincerely grateful to have an opportunity to discuss this (I’m mega worried now).

Many thanks - Kaz

 

[kaz]

OOOps... forgot to mention that I don't know what is on the other side of the wall - no access, but I'm assuming it would be like eaves.

 

[Nemesis]

Don't panic. It's stood this long...

Nice pointing.

 

[MdB]

If there is no cracking since the restoration 8-9 years ago then it isn't an active problem so as Nem says, don't panic. However, it looks to me that it has moved since the tie bar was put in as the bricks above it have shifted. I would still get an expert in to check.

 

[FamilyWiggs]

I am certainly no expert - and with the caveats of Nemesis and MdB about this looking like historical movement and so less of a worry....

However, to my eye, and based upon your arrows, these do look like two structural/load bearing walls. Am I right that the 2 walls in question are the front wall of the house and what used to be the end wall which now has the half-height extension on the other side? If so, then I wouldn't panic, but I would get a structural engineer to have a look - and one who understands historical buildings.

Your average surveyor won't understand fully what he is looking at, and will likely recommend all sorts of unnecessary remedies. You'll need one who understand traditional construction techniques and the balance of risk and reward that living in an old property contains.

If you let us know which part of the country you are in, I am sure someone on here will recommend an engineer to you.

Good luck and please let us know how you get on.

Robin

 

[FamilyWiggs]

BTW - what are coffin boards?

 

[Penners]

As Nemesis has said, don't get too worried about this. From the relatively intact appearance of the external brickwork, it doesn't look as though it's a panic-stations situation.

Nevertheless, I think you're right to be looking for some sort of clear idea of what's going on, with a view to avoiding any potential future problems.

Could we just be clear about the construction of the wall in question? The exterior is obviously brickwork, but in your first picture it looks as though there may be a horizontal timber plate that has pulled away from whatever it originally joined (a corner post?). This, together with the interior beams shown in your lower picture, suggest that this is a timberframe property with an external brick skin.

If that is the case, then the fairly undamaged appearance of the bricks (other than some displacement where the "S" plate is - which perhaps needs watching) suggests that the exterior brickwork was possibly added after the timber frame pulled apart where your crack is. This suggests that the crack has existed for quite some time, and is probably stable.

The changed direction of the interior ceiling joists in the room below simply indicate that the far part of the room is in the extension, which was probably added later, and constructed a bit differently.

I can only tell you what I would do if my assumptions above are correct. I would try to get some ironwork made up to anchor the pulled-apart plate and post back together (just anchor them as they are - don't try to pull them back together). As Me! has suggested, I would pay particular attention to the very top of the corner where the crack is, to see whether the roof plate has also pulled apart at the corner. If so, I would also get some ironwork brackets made to anchor this together (in its current position). I would then cover the crack with some short laths and plaster over them, flush with the existing good plaster.

One final thought. You sound as though you don't have a great deal of experience of structural repairs (no insult intended, but it is important). If this is the case, then I think you should - as MdB suggests - employ a structural engineer to have a look at the problem and make his/her recommendations. Any suggestions you receive here will be based on a lot of assumptions.

 

[Nemesis]

It's a lovely house - really, don't panic. Old houses are full of these sort of surprises.

The external repairs, if carried out as long ago as you say, are holding up fine (I'm assuming that's lime...).

If the surveyor who looked at the property is one with historic buildings expertise, it may be worth a call, and it also may be worth tracking down the previous owner, or talking to a neighbour, to ask about work carried out, if there's no paperwork with the purchase.

 

[chuckey]

Looking at pic #3, where the big beam crosses the main room, that was the position of the original house wall. When the extension was built they knocked through that wall and tried to take the weight of the upper half of the wall and 1/4 of the roof on that "big" beam. when the mortar dust started falling, the builders reckoned they had to take some weight off the beam, so they removed the upper half of the wall, supporting the roof on the stud work. Whew!, that was a close one. They then went around and tried to pull the structure back to true with the S plate as the front wall did not have the side wall to keep it upright.
All in all, a close one for the house, but as it has not moved for 50+ years, not much trouble for you. These houses without any gables end (i.e. "hipped" all round) have a terrible tendency to "spread" and push the wall tops out. In one axis the rafter/wall plates/ceiling joists junction could be tied together. In the other axis, a couple of ties right across from rafter to rafter would help.
Get some nice clean brown paper and a bucket of plaster.
Frank

 

[arthurw3]

 

[kaz]

Thank you again for the support / suggestions. Sorry I’ve taken a while to reply, but I’ve been re-reading the survey report (83 pages). I am trying hard to understand everything and have had a chat with a neighbour who’s lived in the village for zonks. He’s thrown a bit of light on things.

Looking at the survey report it describes the house as having a timber frame primary structure which would have been in filled with wattle and daub. The Georgian brick frontage was added at a later date (there is also some brickwork to the rear on this part of the house only).

There is a problem with the roof on that corner… the survey report recommends that a roofer re-beds the tiles (without actually getting on the roof). See pic. I hadn’t thought of the connection this may have with the crack.

The report also mentions the sole plate and that it can often be a concern in timber framed properties. He suggests that I dig a French gully around the house (that should keep me out of mischief for an hour!).

The neighbour tells me that he heard that prior to the property being extended in that area, the ‘old’ exterior wall mostly comprised of a chimney stack.

The surveyor specialises in older properties and ‘face to face’ he said plenty to reassure me… e.g. the house isn’t about to fall down, but I need to be proactive and come up with a 5 year maintenance plan. He also said that I should start assessing changes using a check list e.g. crack appeared / worsened, etc. However, the report seems far more negative than the verbal comments made on the day of the survey.

Reading your theory Frank made sense… I think that’s what may have happened.

So just to round up… I need to contact the surveyor and ask him to come and have a look at what’s been recently uncovered (I’m not sure if he is a structural engineer – I’ll check)?

Many thanks again (please don’t abandon me!)

Arthur... it helps greatly to see that there's hope... thank you for sharing the photos.

Kaz.

 

[FamilyWiggs]

Arthur - I think you pics are the wrong way round. Either that or you have put a very nice crack into a perfectly good wall! No wonder your techniques draw some concern on here!

:lol:

 

[Me!]

As others have said, there is obviously some historic movement around the S plate, but it doesn't look recent to me.
Looking at your internal picture showing the beams, it looks like the large vertical beam (that supports the main horizontal one) is very much in the room rather than in the wall. I have something similar in my house, and it seems to be that the 'new' brick frontage was built slightly further out than the original timber framed outer wall. This could easily account for a large vertical gap at the outer edge of internal walls where they now fail to meet the, now further away, outer wall.

 

[Lime]

It is all a matter of degree as to how serious this is.

I suppose what concerns me is that the wall tie has not stopped the brickwork moving outwards from the house and the people in the past, and not so long ago IMO, just covered up the evidence of movement without doing any remedial work.
The thoughts that flows from that is that there is probably more cover up elsewhere which could be serious and that the movement is on going.
The roof suggests that the roof timbers are dropping/dropped below the outer skin of brick and may or may not be serious.
Perhaps the wall that was removed from the downstairs room caused structural settlement of the frame and hence the drop.

As I see it there has been movement of the upper brickwork since the tie was fitted and nothing else has been done to stop the movement except covering up.
I don't think there is any evidence apparent to show corrective work has been carried out since.

 

[chuckey]

Look at the curvature on the ridge (?) tiles on the last picture.Unless the builders used a new form of exponentialy curved roof lines, I think it should be straight, the bottom end has bent outwards causing the curve. Each roof slope will have a "belly" in it (not really correct term as most bellies are convex and the curvature is concave). Ties are required from side to side on the bottom of the rafters. Any purlins should also be propped onto internal walls and/or braced as opposite pairs.
Round here, inspite of being conventional ridge roofs, loads of roofs have this form of curvature on them. Looks very picturesque, local roofers ignore the bumps and dips and re-lay the flags as though the roof was flat(?) .
Frank