Lateral Movement?

[8ball]

OK so back in April 2015 I made a post on Ebuild regarding taking out a block wall which became redundant due to other projects but now it needs doing so I am re-posting but this time with a bit more information as my investigation work has been a lot more thorough.

 

So here goes, I need to remove a single skin block built non load bearing wall. The wall is a dividing a kitchen and a dinning room and is part of a single/double story wrap around extension that was built back in 1985. Once the wall is removed it will create a large L shaped kitchen diner hopefully.

 

Here is a pic of the single story extension:

 

The wall in question is marked in red to the right just inside the double doors please see pic below:

 

As you can see from the pic below there is a boxed in steel lintel marked in yellow/black running across from the outside cavity wall (marked in Orange)to an internal wall which used to be the exterior of the house this is a cavity wall measuring 3 metres in length and built from block and brick(used to be load bearing but no longer is). The cavity wall then takes a 90 degree turn forming the back of the single story Kitchen extension(becomes load bearing), this was originally the back corner of the house before the extension was built.

 

 

The single skin block wall that needs removing is not tied to the internal cavity wall but is tied to the outside single story 8 metre long wall (pics below), also wanted to note that this is the only internal wall stretching from the old exterior of the house to the 8 metre long back wall of the single story extension.

 

 

All the top rafters sit on a wall plate bolted to the wall with supports at various intervals transferring weight down to the bottom rafters with one giant nail steadying each rafter. All the bottom rafters are built into the wall, 2 bottom rafters in the roof sit either side of the wall that wants removing. I have taken a couple of pics to show the roof structure as below:

 

The archway (98cm width) in the non load bearing double skin wall is being made wider creating a opening of 152cm, stone arch will be removed and a standard square opening created. See pics below of both sides of arch:

 

 

My concerns are:

Removing the single skin block built non load bearing wall will leave an 8 metre long exterior wall laterally unsupported apart from its ends but will the roof help to keep this in place?

 

 

Expanding the width of the archway to the left and removing the single skin block wall to the right of the double skinned load bearing wall will surely leave it vulnerable to lateral movement?

 

 

 

Really sorry for the giant post but I wanted to make sure that I provide as much info as possible thus avoiding any costly mistakes.

 

Cheers

Edited June 2, 2017 by 8ball

[Brickie]

Could you show the layout & proposed changes on plan?

[8ball]

55 minutes ago, Brickie said:

Could you show the layout & proposed changes on plan?

I'll rev up the laptop and get on it

[8ball]

[PeterW]

Is the main steel under the back wall a single run ..? Watch for bearing ends and a minimum

bearing on the padstone. 

 

1200mm of blockwork is fine as a supporting wall assuming it's built well - doubling it in thickness is an option if you are worried and there is a footing below it 

[8ball]

12 hours ago, PeterW said:

Is the main steel under the back wall a single run ..? Watch for bearing ends and a minimum

bearing on the padstone. 

 

1200mm of blockwork is fine as a supporting wall assuming it's built well - doubling it in thickness is an option if you are worried and there is a footing below it 

The lintel sits on the back wall which is the original outside wall of the house, it's a cavity wall made from block and brick. I,m worried that taking materials from either side of this wall will leave it unstable the same goes for the 8 metre long outside wall.

Edited June 3, 2017 by 8ball

[Temp]

Check the pad stone under the 2.8m steel as it may well extend over the area you want to remove.

Re 8m external wall - check part A for the buttress requirements of long walls. 

 

[8ball]

1 hour ago, Temp said:

Check the pad stone under the 2.8m steel as it may well extend over the area you want to remove.

Re 8m external wall - check part A for the buttress requirements of long walls. 

 

Thanks for the heads up on the padstone Temp, I have read through Part A and after a few diagrams and calcs the exterior wall is OK but I am now going to keep part of the internal wall in place as a buttress and adding some of the blocks I take out to make it double thickness just to settle my over cautious mind. 

 

Cheers Temp