Bungalow internal wall taking purlin? Foundation depth

[tombo8383]

Hi,

 

I’m in the process of fully renovating a 1950’s bungalow. One part of the project is dealing with an internal blockwork wall which is running from below floor level - 400mm below suspended timer floor directly off compacted hardcore, all the way up to the loft area, then switching to bricks and supporting the purlin (hipped roof). I’d like to rebuild this wall 1m further right at the centre of the span of the purlin, and then remove the original wall, but I’m unsure of what will be required to build a new blockwork wall off. I’m planning to remove the entire timber suspended floor and infill with a new insulated solid floor (with UFH). Will be a great time to rebuild this wall, in a more convenient location to take the weight of the purlin and knock down the old blockwork wall. The current load bearing wall seems to be built off compacted hardcore under the floor. I’m assuming that Building regulations will require me to cast some sort of concrete foundation to take the new 100mm blockwork wall, but surely they won’t require it to be 1m deep excavation? I’ll obviously go off what the BRegs require, but would like to know if it’s feasible to rebuild the wall off more shallow foundations than 1m? 
 

photo1 - In loft, the purlin being supported by the brickwork, which is sitting on the blockwork wall I’d like to rebuild. 
 

photo2 - the blockwork wall

 

photo3 - under the suspended floor showing brickwork off compacted hardcore, switching to blockwork above floor level, going back to brickwork in the loft space directly under the purlin.

 

thanks for any advice or tips

 

Tom 

[ProDave]

I very much doubt that wall is just built on the compacted hardcore, I bet you will find it extends down to some footings.

 

You will need to discuss the foundations for the new wall with your BCO.

[tonyshouse]

I have seen lots of internal loadbearing wall built off the slab with no foundations under them common in the 50’s 

 

some had gone down a bit.

 

you may be able to add a truss or girder beam in the loft or an rsj/gloelam, pleas put it above the ceiling 

[tombo8383]

Just an update: I have a dig today and there is some sore of concrete footing underneath the wall currently. Does anyone know very roughly the sort of depth that would be required for a new wall internally? Surely not 1m? 
I will obviously consult Building Regs, but trying to plan ahead. 

[MikeGrahamT21]

Are you wanting to move this wall to a different location?

 

If so, you'll need to consult a structural engineer to see how far you can move it, as the area for supporting the timber will likely sit in a particular zone in the middle.

[tombo8383]

I do want to move it, but currently it’s around a metre off centre of the span of the purlin. Convenient for the bedroom wall. I want to build the new wall exactly in the middle of the span so perfectly distributing the load. 

[Dave666]

I realise this topic is over 2 years old but I am in a very similar situation, again a bungalow with a block wall continuing into the loft to support a purlin.

 

The section of purlin has a total span of 7m (no joins) - the wall splits the space  into 2 rooms (2.5m  & 4.5m in length). I would like to remove the wall and replace with a new wall giving me two rooms of 3.5m in length (i.e. supporting purlin at its mid point). 

 

I was wondering if the original poster (tombo8383) completed their project and if so what solution was chosen?

 

I am leaning towards going for a non-load bearing stud wall & a RSJ running above it with a post to support the purlin (this would mean no new footings required) but still not 100% sure. 

 

Suggestions from the original poster or anyone else appreciated.

Edited May 18, 2022 by Dave666
typo