Victorian house: unbonded intersecting walls?

[PoundofCarrots]

I have just removed an old fitted wardrobe from the second (top) floor of our Victorian house. The removal revealed an area of blown plaster which came away easy revealing the brickwork. Exposure of the brickwork also shows that the two intersecting walls (internal front and side) do not appear to be bonded. There was a lot of crumbling mortar and the ends of some of the London stock bricks have corroded away.

I have removed plaster almost from ceiling to floor in the corner where the walls join to get a better look and have attached a basic picture to try and give a clearer idea together with my description.

My neighbour, who is reasonably knowledgeable, had a look and advised me to fill the gaps with 3:1 mortar before plastering over. While I was at the builders merchants this morning I explained the situation to one of the staff who told me that Victorian houses sometimes have this gap to allow for movement/expansion and that filling this gap with mortar could prevent this.

If anybody could offer their opinions on any of the above, I would be very grateful.

Thanks in advance.

Untitled

• PoundofCarrots
• 4 Jun 2013
• 1

Untitled

• PoundofCarrots
• 4 Jun 2013
• 1

Untitled

• PoundofCarrots
• 4 Jun 2013
• 1

 

[TheVictorian]

Mine had pretty much exactly the same gap, as any movement occurred a long time in the past I filled it with mortar and brick slips.

 

[PoundofCarrots]

Thanks for your reply. I've posted some better quality images in case anybody else has any experience with this.

I'm not sure whether our house still has movement or not but next door have had their cracks 'measured' over the previous year and there hasn't been a huge deal of movement.

Is this sort of gap intended then?

 

[TheVictorian]

I've never been able to find out if they were deliberate or not to be honest. However comparing mine to yours they are almost identical and it would be a lot of movement to force a crack that big to appear, especially with no other effects being noticeable.

 

[stuart45]

Party walls were supposed to be tied in, but it was quicker to build them like that.

 

[tony1851]

The man at the builder's merchants is talking rubbish; one day someone will write a book about the myths that come out of the merchant's yards.

Frequently in older houses, party walls were built first, and then they followed on with the front and rear walls. Consequently, the bond between the walls is casual at best, and non-existant otherwise.
It's perfectly normal for a house of that age.
Don't fill gaps with 1:3 - that's far too strong and it will just shrink and possibly crack more bricks. Use a softer mortar, and don't fret about it!

 

[stuart45]

Frequently in older houses, party walls were built first, and then they followed on with the front and rear walls.

Much easier to bump out the party wall when it's done first.

 

[dann09]

Are you saying that i'm looking at two internal walls that intersect at that inside corner? If so, whats the condition on the other side of either wall?

Cracks can be seen in the brickwork of the RH wall, if you hacked off more plaster from both walls and pic'ed the results on here it might help.

Vegetation or some other kind of strands can be seen at the ceiling join - have you examined the issue from the loft? Remedial plastering has taken place at some past time.

Has an historic knock-thro taken place, or a chimney breast been removed, in the vicinity? Is the floor level in that corner?

 

[PoundofCarrots]

Thank you for your replies. Yep these builders merchants yards seem to be a hotbed of testosterone and bluster!

In answer to dann09's questions. Yes: they are two internal walls joining in the right hand corner of the room (facing out towards the street).

I can take off a bit more plaster tomorrow to investigate further.

The strands you can see protruding at the top of the wall are bits of a fabric type netting that I think comes from above the ceiling. My neighbour told me the name of the stuff but I'm afraid I've forgotten.

Because it's up on the second floor, I haven't been able to inspect the external walls closely, but in general the pointing and brickwork on the external wall is in good condition.

I'm not aware of any knock-throughs or chimney removals and the floor is generally level in that corner.

I hope that helps and thanks again!

 

[stuart45]

The strands you can see protruding at the top of the wall are bits of a fabric type netting that I think comes from above the ceiling. My neighbour told me the name of the stuff but I'm afraid I've forgotten.

Scrim

 

[PoundofCarrots]

That's the one.

 

[dann09]

Thank you for setting me straight on the scrim.

However, it now seems that we are looking at the inside faces of two external walls, and that corner is the outside corner of the building? Correct me if i've got it wrong.

 

[PoundofCarrots]

Yes, sorry, you're partly right. The wall on the left of the picture is the interior side of the front external wall of the house but the wall on the right of the picture is the inside face of the party wall with next door's terrace.

I hope this is clear enough.

 

[tony1851]

It's not unusual. Just pack some broken bricks and mortar in the gap.
You only really need to think about mechanically tying the walls together if there is evidence of continuing movement.

 

[PoundofCarrots]

Thanks again for your input. I got the render on today. Used about a 5:1 mix. Hope this is ok. Packed out the gaps as advised.

Approximately how long do you think I should leave the render before I apply any plaster over it?